Sacramento Municipal Utility District's Upper American

SACRAMENTO MUNICIPAL UTILITY DISTRICT’S

UPPER AMERICAN RIVER PROJECT

(FERC Project No. 2101)

and

PACIFIC GAS AND ELECTRIC COMPANY’S

CHILI BAR PROJECT

(FERC Project No. 2155)

TECHNICAL REPORT ON

HYDROLOGY

APRIL 2004

Pacific Gas and Electric Company Sacramento Municipal Utility District Chili Bar Project Upper American River Project FERC Project No. 2155 FERC Project No. 2101

TABLE OF CONTENTS

Section & Description Page

1.0 INTRODUCTION ...... 1 2.0 BACKGROUND ...... 2 2.1 Hydrology Study Plan...... 2 2.2 Water Year Type...... 3 2.3 Agency Requested Information ...... 4 3.0 COMPUTATION OF MEAN DAILY DATA...... 5 3.1 Available Data ...... 6 3.2 Methodology...... 17 3.2.1 South Fork Silver Creek at Ice House Reservoir...... 18 3.2.2 Rubicon River at Rubicon Reservoir ...... 35 3.2.3 Little Rubicon River at Buck Island Reservoir...... 46 3.2.4 Gerle Creek and South Fork Rubicon River...... 54 3.2.5 Silver Creek at Union Valley Reservoir ...... 76 3.2.6 Silver Creek at Camino Reservoir Including Brush Creek...... 86 3.2.7 South Fork American River at Slab Creek Reservoir...... 110 3.2.8 South Fork American River at Chili Bar Reservoir...... 113 4.0 ACCRETIONS ...... 127 4.1 Computation of Daily Accretions ...... 127 4.2 Computation of Monthly Accretions ...... 128 5.0 FLOW STATISTICS...... 129 5.1 Magnitude of Monthly Water Conditions (IHA Group 1)...... 130 5.2 Magnitude and Duration of Annual Extreme Water Conditions (IHA Group 2)...... 130 5.3 Timing of Annual Extreme Water Conditions (IHA Group 3)...... 131 5.4 Frequency and Duration of High and Low Pulses (IHA Group 4)...... 131 5.5 Rate and Frequency of Change in Water Conditions (IHA Group 5)...... 131 6.0 DIURNAL DAILY FLUCTUATION ...... 131 7.0 FLOOD PEAK FREQUENCY...... 132 8.0 LITERATURE CITED ...... 133

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Pacific Gas and Electric Company Sacramento Municipal Utility District Chili Bar Project Upper American River Project FERC Project No. 2155 FERC Project No. 2101

LIST OF TABLES

Section & Description Page

2.2-1 Water year types applied to individual months for Water Years 1975-2003 ...... 4 3.0-1 Combined Project Reservoir Release Points...... 5 3.1-1 Existing and Discontinued USGS Gage Records for the Combined Project...... 7 3.1-2 Drainage Area and Average Annual Precipitation...... 11 3.1-3 Elevation Storage-Area Curves...... 12 3.1-4 Net Evaporation Rates at Various Project Reservoirs ...... 15 3.2-1 Streamflow Gages Adjacent to or Nearby the UARP...... 17 3.2.1-1 Evaluation of Drainage Area Elevation Characteristics, An Example ...... 19 3.2.2-1 Computed Unimpaired Inflow Data to Rubicon Reservoir ...... 35 3.2.3-1 Computed Unimpaired Inflow Data to Buck Island Reservoir...... 46 4.1-1 Daily Accretions: Regulation Location Points ...... 127 4.1-2 Daily Accretions: Unregulated Location Points ...... 128 4.2-1 Monthly Accretions: Regulated Location Points...... 129 5.0-1 IHA Analysis: Locations Analyzed ...... 130 6.0-1 Diurnal Daily Fluctuation Analysis, USGS Sites ...... 132 7.0-1 Flood Peak Frequency Analysis Points...... 132

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Pacific Gas and Electric Company Sacramento Municipal Utility District Chili Bar Project Upper American River Project FERC Project No. 2155 FERC Project No. 2101

LIST OF FIGURES

Section & Description Page

3.0-1 Drainage Areas of Project Reservoir Release Points...... 6 3.1-1 Isohyetal Lines...... 11 3.1-2 Storage in Acre-feet ...... 14 3.1-3 Geologic Formations, Sequences and Complexes...... 16 3.1-4 Sedimentary Rocks and Gravels ...... 16 3.1-5 Metamorphic and Igneous Rocks...... 17 3.2.1-1 Ice House Watershed and Nearby Vicinity Schematic Diagram Showing Storage, Diversions and Metering Locations...... 22 3.2.1-2 Inflow to Ice House Reservoir, WY 1995 ...... 23 3.2.1-3 Inflow to Ice House Reservoir, WY 1975 ...... 24 3.2.1-4 Inflow to Ice House Reservoir, WY 1994 ...... 25 3.2.1-5 Ice House Reservoir – Drainage Area Versus Elevation...... 26 3.2.1-6 Ice House Reservoir, Drainage Area Versus Elevation for Simulated Data...... 27 3.2.1-7 Inflow to Ice House Reservoir, WY 1995 ...... 28 3.2.1-8 Silver Creek at Ice House, August Flow Versus July Flow...... 29 3.2.1-9 Inflow to Ice House Reservoir, WY 1995 ...... 30 3.2.1-10 Inflow to Ice House Reservoir, WY 1975 ...... 31 3.2.1-11 Inflow to Ice House Reservoir, WY 1994 ...... 32 3.2.1-12 Double Mass - Cumulative Annual Runoff, 75-01 – SF Silver Creek Below Ice House Reservoir Versus American River at Fair Oaks ...... 33 3.2.1-13 South Fork Silver Creek at Ice House Reservoir, WY 1975-01 – Monthly Box-whisker Diagram...... 34 3.2.2-1 Inflow to Rubicon Reservoir, WY 1995...... 38 3.2.2-2 Inflow to Rubicon Reservoir, WY 1994...... 39 3.2.2-3 Inflow to Rubicon Reservoir – Schematic Diagram Showing Storage, Diversions and Metering Locations – 1993-Present...... 40 3.2.2-4 Inflow to Rubicon Reservoir – Schematic Diagram Showing Storage, Diversions and Metering Locations – 1975-1986...... 40 3.2.2-5 Inflow to Rubicon Reservoir – Schematic Diagram Showing Storage, Diversions and Metering Locations – 1987-1992...... 41 3.2.2-6 Inflow to Rubicon Reservoir, WY 1995...... 42 3.2.2-7 Inflow to Rubicon Reservoir, WY 1994...... 43 3.2.2-8 Double Mass – Rubicon Versus Ice House...... 44 3.2.2-9 Rubicon River at Rubicon Reservoir, WY 1975-01 – Monthly Box- Whisker Diagram...... 45 3.2.3-1 Little Rubicon Watershed and Nearby Vicinity – Schematic Diagram Showing Storage, Diversions and Metering Locations – 1993-2001 ...... 47 3.2.3-2 Little Rubicon Watershed and Nearby Vicinity – Schematic Diagram Showing Storage, Diversions and Metering Locations – 1975-1992 ...... 48 3.2.3-3 Inflow to Buck Island Reservoir, WY 1994 ...... 49

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LIST OF FIGURES

Section & Description Page

3.2.3-4 Inflow to Buck Island Reservoir, WY 1995 (on the x-axis, the plot runs from October 1, 1994 through October 1, 1995)...... 50 3.2.3-5 Inflow to Buck Island Reservoir, WY 1997 (on the x-axis, the plot runs from October 1, 1996 through October 1, 1997)...... 51 3.2.3-6 Double Mass – Buck Island Versus Ice House...... 52 3.2.3-7 Little Rubicon River at Buck Island WY 1975-01, Monthly Box- Whisker Diagram...... 53 3.2.4-1 Gerle Creek Drainage Area...... 57 3.2.4-2 Loon/Gerle/Robbs Watershed and Nearby Vicinity – Schematic Diagram Showing Storage, Diversions and Metering Locations...... 58 3.2.4-3 Inflow to Loon Lake Reservoir, WY 1995 ...... 59 3.2.4-4 Inflow to Loon Lake Reservoir, WY 1994 ...... 60 3.2.4-5 Inflow to Loon Lake Reservoir, WY 1975 ...... 61 3.2.4-6 Inflow to Loon Lake Reservoir, WY 1994 ...... 62 3.2.4-7 SF Rubicon below Gerle Creek, WY 1995...... 63 3.2.4-8 SF Rubicon below Gerle Creek, WY 1994...... 64 3.2.4-9 SF Rubicon below Gerle Creek, WY 1975...... 65 3.2.4-10 Double Mass – Loon, Robbs & Gerle Versus Ice House ...... 66 3.2.4-11 Inflow to Loon Lake Reservoir, WY 1995 ...... 67 3.2.4-12 Inflow to Loon Lake Reservoir, WY 1975 ...... 68 3.2.4-13 Inflow to Loon Lake Reservoir, WY 1994 ...... 69 3.2.4-14 Gerle Creek at Loon Lake WY 1975-01, Monthly Box-whisker Diagram ...... 70 3.2.4-15 Gerle – Robbs, WY 1995...... 71 3.2.4-16 Gerle – Robbs, WY 1994...... 72 3.2.4-17 Gerle – Robbs, WY 1975...... 73 3.2.4-18 Gerle Creek at Gerle Creek Reservoir WY 1975-01, Monthly Box- Whisker Diagram...... 74 3.2.4-19 South Fork Rubicon River at Robbs Peak WY 1975-01, Monthly Box- Whisker Diagram...... 75 3.2.5-1 Inflow to Union Valley Reservoir and Nearby Vicinity – Schematic Diagram Showing Storage, Diversions and Metering Locations (Present) ...... 77 3.2.5-2 Union Valley, WY 1995 ...... 78 3.2.5-3 Union Valley, WY 1975 ...... 79 3.2.5-4 Union Valley, WY 1994 ...... 80 3.2.5-5 Union Valley, WY 1995 ...... 81 3.2.5-6 Union Valley, WY 1975 ...... 82 3.2.5-7 Union Valley, WY 1994 ...... 83 3.2.5-8 Double Mass – Union Valley Versus Ice House ...... 84 3.2.5-9 Silver Creek at Union Valley Reservoir WY 1975-01, Monthly Box- Whisker Diagram...... 85

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LIST OF FIGURES

Section & Description Page

3.2.6-1 UARP Project – Schematic Diagram Showing Storage, Diversions and Metering Locations (1993-2001) ...... 90 3.2.6-2 Camino, Junction and Brush, WY 1995 ...... 91 3.2.6-3 Camino, Junction and Brush, WY 1975 ...... 92 3.2.6-4 Camino, Junction and Brush, WY 1994 ...... 93 3.2.6-5 1986-2001 July – Daily Flow - Forest Creek near Wilseyville Versus Rock Creek near Placerville (adjusted for Rock Creek Powerplant near Placerville) ....94 3.2.6-6 1986-2001 January – Daily Flow - Forest or Pilot Creek Versus Rock Creek near Placerville (adjusted for Rock Creek Powerplant near Placerville)...... 94 3.2.6-7 Double Mass – Rock Creek Versus American River at Folsom...... 95 3.2.6-8 1951-57 January – Daily Flow: Adjusted Silver Creek near Placerville Versus Pilot Creek near Georgetown...... 95 3.2.6-9 1951-57 April – Daily Flow: Adjusted Silver Creek near Placerville Versus Pilot Creek near Georgetown...... 96 3.2.6-10 1951-57 August – Daily Record: Adjusted Silver Creek near Placerville Versus Silver Creek at Union Valley...... 96 3.2.6-11 Camino, Junction and Brush, WY 1995 ...... 97 3.2.6-12 Camino, Junction and Brush, WY 1994 ...... 98 3.2.6-13 Camino, Junction and Brush, WY 1975 ...... 99 3.2.6-14 Double Mass Final– Junction, Camino, Brush Versus Ice House ...... 100 3.2.6-15 Junction (Area A), WY 1995...... 101 3.2.6-16 Junction (Area A), WY 2000...... 102 3.2.6-17 Junction (Area A), WY 1994...... 103 3.2.6-18 Area B, WY 1995 ...... 104 3.2.6-19 Area B, WY 2000 ...... 105 3.2.6-20 Area B, WY 1994 ...... 106 3.2.6-21 Silver Creek at Junction Reservoir WY 1975-01, Monthly Box-whisker Diagram...... 107 3.2.6-22 Silver Creek at Camino Reservoir WY 1975-01, Monthly Box-whisker Diagram...... 108 3.2.6-23 Brush Creek at Brush Creek Reservoir WY 1975-01, Monthly Box- Whisker Diagram...... 109 3.2.7-1 Unregulated SFAR Inflow to Slab Creek Reservoir (SFAR Regulated for P184, Silver Creek Unregulated) WY –1975-01, Monthly Box- Whisker Diagram...... 111 3.2.7-2 Natural SFAR Inflow to Slab Creek Reservoir (Both P184 & Silver Creek Unregulated) WY 1975-96, Monthly Box-whisker Diagram...... 112 3.2.8-1 SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1995...... 115 3.2.8-2 SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 2000...... 116 3.2.8-3 SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1994...... 117

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LIST OF FIGURES

Section & Description Page

3.2.8-4 Double Mass – Water Year Data 1975-2001 – Accretions Chili Bar Versus American River Inflow to Folsom...... 118 3.2.8-5 White Rock Powerhouse Computed Efficiency Pre and Post – Acoustical Velocity Meter Measurement ...... 119 3.2.8-6 SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1980...... 120 3.2.8-7 SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1979...... 121 3.2.8-8 SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1980...... 122 3.2.8-9 SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1979...... 123 3.2.8-10 Double Mass – Water Year Data 1975-2001 – Accretions Chili Bar Versus American River Inflow to Folsom ...... 124 3.2.8-11 Unregulated SFAR Inflow to Chili Bar Reservoir (SFAR Regulated for P184, Silver Creek Unregulated) WY 1975-01, Monthly Box-whisker Diagram...... 125 3.2.8-12 Natural SFAR Inflow to Chili Bar Reservoir (Both P184 & Silver Creek Unregulated) WY 1975-96, Monthly Box-whisker Diagram...... 126

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LIST OF APPENDICES

Appendix & Description Page

APPENDIX A A COMPUTATION OF SIMULATED DATA INFLOW TO ICE HOUSE RESERVOIR (PROVIDED IN HARDCOPY AND ON CD) APPENDIX B MONTHLY UNIMPAIRED FLOW (MONTHLY DATA PROVIDED IN HARDCOPY AND ON CD; DAILY DATA PROVIDED ON CD ONLY) APPENDIX C COMPUTATION OF SIMULATED DATA INFLOW TO JUNCTION, CAMINO AND BRUSH CREEK RESERVOIRS (PROVIDED IN HARDCOPY AND ON CD) APPENDIX D COMPUTATION OF SIMULATED DATA ACCRETIONS (PROVIDED IN HARDCOPY AND ON CD) APPENDIX E IHA ANALYSIS (PROVIDED ON CD ONLY) APPENDIX F DIURNAL DAILY FLUCTUATION (PROVIDED IN HARDCOPY AND ON CD) APPENDIX G FLOOD PEAK FREQUENCY DATA AND CURVES (PROVIDED IN HARDCOPY AND ON CD)

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HYDROLOGY TECHNICAL REPORT

SUMMARY

This report includes the following analyses: • Computation of mean daily data: Development of mean daily flow data at all reservoir release points for both unregulated and regulated conditions for water years 1975 through 2001. ο Introduction - Summary of available data including and discussion of points where unregulated data and regulated data are provided. ο Methods - Summary of methods used to compute calculated unimpaired mean daily flow and synthesized unimpaired mean daily flow. ο Results - Summary of unregulated mean daily flow data (box-whisker diagrams and average annual flow). • Computation of monthly accretions (Note that this has been revised to a computation of daily accretions for all points described above Chili Bar Reservoir): Development of mean daily accretions for locations described by the Water Balance Subcommittee (8 October 2003) for water years 1975 through 2001. ο Introduction - Summary of locations where flow is computed. ο Methods - Summary of methods used to compute accretions. ο Results – Summary of unregulated mean daily accretions data. • Computation of flow statistics: Development of mean daily flow statistics for selected locations using data for water years 1975 through 2001. ο Introduction - Summary of available data where statistics are computed. ο Analysis – Assess project effects of the unregulated flow characteristics. IHA methodology is applied. • Hourly Flow Data: Evaluate diurnal fluctuations in unregulated flow data for the South Fork Silver Creek downstream of Ice House Dam and the South Fork American River downstream of Slab Creek Dam using hourly flow data from representative unregulated watersheds nearby the UARP for water years 1990 through 2001. ο Introduction - Summary of available data including and discussion of points where analysis will be performed. ο Methods - Summary of methods used to evaluate daily diurnal fluctuations. ο Results - Graphical presentation of relationship between mean daily flow and maximum daily flow during the spring snowmelt. • Annual Peak Flow Data: Summarize annual peak flow data at all gage locations in the Project area with long- term regulated and unregulated peak flow information. All available peak flow data is used in this analysis. ο Introduction - Summary of available data including and discussion of points where analysis is performed. ο Methods - Application of U.S. Army Corps of Engineers statistical methodology. ο Results - Graphical presentation of flood-peak frequency analysis.

1.0 INTRODUCTION

This technical report is one in a series of a reports prepared jointly by the Sacramento Municipal Utility District (SMUD) and Pacific Gas and Electric Company (jointly referred to as the Licensees) to support the relicensing of SMUD’s Upper American River Project (UARP) and Pacific Gas and Electric Company’s Chili Bar Project (jointly referred to as the Projects). The Licensees intend to append this technical report to their respective applications to the Federal Energy Regulatory Commission (FERC) for a new licenses. This report addresses the distribution and abundance of special-status amphibian and aquatic reptile species and suitable habitat in Projects reservoirs and in streams affected by the Projects reservoirs, including the

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Reach Downstream of Chili Bar. This section of the South Fork American River is downstream of the Pacific Gas and Electric Company’s Chili Bar Project.

• BACKGROUND – Includes when the applicable study plan was approved by the UARP Relicensing Plenary Group; a brief description of the issue questions addressed, in part, by the study plan; the objectives of the study plan; and the study area. • DESCRIPTION OF ANALYSIS AND RESULTS BY SUBJECT AREA o METHODS – A description of the methods used in the study, including a listing of study sites. o RESULTS – A description of the most important data results. Raw data, where copious, and detailed model results are provided in a separate compact disc (CD) for additional data analysis and review by interested parties. o ANALYSIS – A brief analysis of the results, where appropriate. • LITERATURE CITED – A listing of all literature cited in the report.

This technical report does not include a detailed description of the UARP Alternative Licensing Process (ALP) or the Project, which can be found in the following sections of the Licensee’s application for a new license: The UARP Relicensing Process, Exhibit A (Project Description), Exhibit B (Project Operations), and Exhibit C (Construction).

Also, this technical report does not include a discussion regarding the effects of the Project on hydrology or associated environmental resources, nor does the report include a discussion of appropriate protection, mitigation, and enhancement measures. An impacts discussion regarding the UARP is included in the applicant-prepared preliminary draft environmental assessment (PDEA) document, which is part of the Licensee’s application for a new license. Development of resource measures will occur in settlement discussions, which will commence in early 2004, and will be reported in the PDEA.

2.0 BACKGROUND

2.1 Hydrology Study Plan

On August 7, 2002, the UARP Relicensing Plenary Group approved the Hydrology Study Plan that was developed and approved by the Aquatic Technical Working Group (TWG) on June 24, 2002. The study plan was designed to address, in part, the following questions developed by the Plenary Group:

Issue Question 17. How has the Project affected the timing and natural hydrology in all Project reaches and tributaries? What are the effects on habitat and geomorphology?

Issue Question 43. What are the unimpaired (pre-Project) and regulated flows in the Project area? What is the range of variability of those flows?

This technical report addresses these issue questions with the exception of effects on habitat and geomorphology, which are addressed in separate technical reports (i.e., Stream Habitat, Reservoir Habitat and Amphibians Test Flow technical reports).

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For the purpose of the study, “natural flow” was defined as the unregulated streamflow computation adjusted for regulation and diversions from upstream projects including Project 184 and the UARP and Chili Bar projects; ”unregulated flow” was defined as the unregulated streamflow computation adjusted for regulation and diversions made by the UARP and Chili Bar projects; and “regulated flow” referred to the observed or measured flow (not adjusted for regulation and diversion upstream of station).

The study objectives were two fold. First, to develop a stream flow database composed of:

• Mean Daily Data: Develop mean daily flow data at all reservoir release points for both unregulated and regulated conditions for period of record from Water Year 1976 through 2001.

• Hourly Flow Data: Evaluate diurnal fluctuations in unregulated flow data for the South Fork Silver Creek downstream of Ice House Dam and the South Fork American River downstream of Slab Creek Dam using hourly flow data from representative unregulated watersheds nearby the UARP for the period from Water Year 1990 through 2001.

• Annual Peak Flow Data: Summarize annual peak flow data at all gage locations in the Project area with long-term regulated and unregulated peak flow information. All available peak flow data will be used in this analysis (i.e., as early as WY 1925 through WY 2001).

• Monthly Accretion Flow Estimates in Project Reaches: Synthesize monthly accretion flow data at the bottom of all Project Reaches, including contributions from significant tributaries for the period from Water Year 1976 through 2001.

The second objective was to assess Project effects on the unregulated flow characteristics including:

• Flow Statistics: Where data are not limiting the analysis, analyze mean daily flow data.

• Flood Peak Frequency Analysis: Develop flood peak frequency curves (annual-event curves), with separate curves developed for regulated and unregulated conditions.

• Diurnal Flow Analysis: Investigate the relationship between mean daily flow and minimum or maximum daily flow during the spring snowmelt.

The study plan specifically listed that an Indicators of Hydrologic Alteration (IHA) analysis, a flood peak frequency analysis, and a diurnal flow analysis would be performed.

The study area encompassed all Project Reaches, including the Reach Downstream of Chili Bar.

2.2 Water Year Type

The information in this subsection is provided for informational purposes, as requested by agencies. The derivation of water year types is described in the Water Quality Technical Report. Note that the types in Table 2.2-1 below are those that would result from the application of the

SMUD UARP/Study Report/Hydro_redline accepted_42704.doc Page 3 of 133 Sacramento Municipal Utility District Pacific Gas and Electric Company Upper American River Project Chili Bar Project FERC Project No. 2101 FERC Project No. 2155 water types proposed by the UARP Relicensing Water Year Type Subgroup to the period of record, and not those water year types that actually were applied in conformance with the existing UARP or Chili Bar licenses. Table 2.2-1 presents water year types for the period that is pertinent to this Hydrology Technical Report.

Table 2.2-1. Water year types applied to individual months for Water Years 1975 through 2003. (CD=Critically Dry; D=Dry; BN=Below Normal; AN=Above Normal; W=Wet) Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1974 ------W W W 1975 W D BN BN AN AN AN AN AN AN AN AN 1976 AN D D CD CD CD CD CD CD CD CD CD 1977 CD CD CD CD CD CD CD CD CD CD CD CD 1978 CD AN AN AN W W W W W AN AN AN 1979 AN D BN BN BN BN BN BN BN BN BN BN 1980 BN AN W W W W W W W W W W 1981 W D D D D D D D D D D D 1982 D W W W W W W W W W W W 1983 W W W W W W W W W W W W 1984 W W W W W W W W W W W W 1985 W BN BN BN D D D D D D D D 1986 D BN W W W W W W W W W W 1987 W D D D CD CD CD CD CD CD CD CD 1988 CD BN D CD CD CD CD CD CD CD CD CD 1989 CD D D BN BN BN BN BN BN BN BN BN 1990 BN D D D D D D D D D D D 1991 D CD CD D D D D D D D D D 1992 D D D D D D D D D CD CD CD 1993 CD AN AN AN AN AN AN AN AN AN AN AN 1994 AN D D D CD CD CD CD CD CD CD CD 1995 CD W AN W W W W W W W W W 1996 W BN AN AN AN AN AN AN AN W W W 1997 W W W W W W W W W W W W 1998 W AN W W W W W W W W W W 1999 W AN W AN AN AN AN AN AN AN AN AN 2000 AN BN AN AN AN AN AN AN AN AN AN AN 2001 AN D D D D D D D D D D D 2002 D BN BN BN BN BN BN BN BN BN BN BN 2003 BN BN BN D BN BN BN BN BN ------

2.3 Agency Requested Information

In a letter dated December 17, 2003 to the Licensee regarding content of technical reports, the agencies requested that the Hydrology Technical Report include (besides the information listed in the Hydrology Study Plan):

• Updated, corrected report • Flood frequency analysis

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3.0 COMPUTATION OF MEAN DAILY DATA

The Licensee’s methods conformed to the methods in the study plan, with the exception that the Licensee’s study period began in Water Year 1975 rather than Water Year 1976.

This document summarizes the results of the Hydrology Study Plan Mean Daily Flow Analysis prepared for SMUD’s Upper American River Project (UARP or Project) and PG&E’s Chili Bar Project (Chili Bar). The UARP and Chili Bar projects will be referred to as the Combined Project. Daily data for this analysis are provided in an electronic format on the accompanying CD. Included in this document is a description of the computation of unimpaired mean daily flow for the drainage areas at the following reservoir release points:

Table 3.0-1. Combined Project Reservoir Release Points Rubicon River at Rubicon Reservoir South Fork Silver Creek at Ice House Reservoir Little Rubicon River at Buck Island Reservoir Silver Creek at Junction Reservoir Gerle Creek at Loon Lake Silver Creek at Camino Reservoir South Fork Rubicon River at Robbs Peak Reservoir Brush Creek at Brush Creek Reservoir Gerle Creek at Gerle Creek Reservoir South Fork American River at Slab Creek Reservoir Silver Creek at Union Valley Reservoir South Fork American River at Chili Bar Reservoir

The period of record analyzed was October 1, 1974 through September 30, 2001 (water years 1975 through 2001). Figure 3.0-1 delineates several of the drainage areas described in Table 3.0- 1.

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Figure 3.0-1

3.1 Available Data

The United States Geological Survey (USGS) and SMUD have monitored reservoir storage, powerhouse draft, releases at reservoirs and tunnel diversions for many points within the drainage basin. Available data are summarized in Table 3.1-1.

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Table 3.1-1. Existing and Discontinued USGS Gage Records for the Combined Project Gage Drainage USGS Elevation Area Number USGS Description Notes (feet) (sq-mi) Period of Record Stream/River Flow Gages 11427960 Rubicon River below The gage only measures 6,520 29.8 Published: 10/91 Rubicon Dam near Meeks low flows less than 10 to present. The Bay, CA cfs; however, SMUD USGS records has provided estimates indicate that there of daily spill for the is unpublished period 1993 to present record for the and for some years period 1964-91; prior to this period. however, they were unable to locate the record. SMUD also has some sporadic measurements for the Rubicon River above the reservoir for the period 1975-91. 11428000 Rubicon River at Rubicon Gage located 31.6 2/1/10-12/31/13 (formally Springs, CA downstream of present 10/1/56 –9/30/86 gage 391) Rubicon Dam, 0.75 mile upstream of Miller Creek 11428400 Little Rubicon River The gage only measures 6,420 6.0 Published: below Buck Island Dam low flows less than 2 10/1990 to present near Meeks Bay, CA cfs; however, SMUD The USGS has provided estimates records indicate of daily spill for the that there is period 1993 to present unpublished and for some years record for the prior to this period. period 1964-91; however, they were unable to locate the record. 11429500 Gerle Creek below Loon Records Loon Lake 6,250 8.0 9/1962 to present Lake Dam near Meeks spill and release Bay, CA 11430000 South Fork Rubicon River Includes release and 4,970 47.6 8/1961 to present below Gerle Creek near spill from Gerle and Georgetown, CA Robbs Peak Reservoirs 11441000 Silver Creek at Union Gage was located near 82.7 10/1/24-12/31/27 (formally Valley, CA present Union Valley 10/1/28-1/31/50 gage 414) Dam, 0.6 mile 7/27/50-2/28/51 downstream of 8/31/51-9/30/60 confluence of Big Silver and Jones Fork creeks.

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Table 3.1-1. (continued) Gage Drainage USGS Elevation Area Number USGS Description Notes (feet) (sq-mi) Period of Record 11441500 South Fork Silver Creek Gage was located near 5,290 27.2 10/1/24-12/31/57 (formally near Ice House, CA the present Ice House gage 415) Dam, 0.3 mile downstream of Peavine Creek 11441500 South Fork Silver Creek Records Ice House 5,290 27.5 1/58 to present near Ice House, CA Reservoir spill and release 11441800 Silver Creek at Junction Gage monitors low 4,280 147 Published: Dam near Pollock Pines, flows only (<30 cfs); 10/1987 to CA however SMUD has present. The estimated daily spills USGS records for the period 1993 to indicate that there present. is unpublished record for the period 1965-87; however, they were unable to locate the record. 11441900 Silver Creek below Records Camino Dam 2,754 171 10/1960 to present Camino Diversion Dam, spill and release plus CA Round Tent Canyon 11442000 Silver Creek near Gage was located 0.2 177 5/1/22-9/30/61 (formally Placerville, CA mile upstream of gage 417) confluence with SFAR. 11442700 Brush Creek below Brush Flow released from 2,700 8.0 Published: Creek Dam near Pollock Brush Creek Dam. 10/1987 to Pines, CA SMUD has estimated present. The daily spills for the USGS records period 1993-present. indicate that there is unpublished record for the period 1971-87; however, they were unable to locate the record. 11443500 South Fork American Records Slab Creek 1,625 493 10/1922 to River near Camino, CA Dam spill and release present 11444201 Rock Creek near Records flow over 1,305 73 10/1/1986 to Placerville broad-crested weir and present sharp-crested weir. Water diverted immediately upstream to Rock Creek Powerplant (11444280) 11444500 South Fork American Records Chili Bar spill, 931 598 10/1/1964 to near Placerville release and flow present through Chili Bar Powerhouse

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Table 3.1-1. (continued) Gage Drainage USGS Elevation Area Number USGS Description Notes (feet) (sq-mi) Period of Record 11445500 South Fork American Flow 635 673 10/1/1951 to near Lotus 9/30/1995 11446000 Weber Creek near Salmon Flow 610 97.6 4/1/1943 to Falls 9/30/59 Powerhouse and Tunnel Flow 11427940 Rubicon-Rockbound Flow that is diverted to 6,533 N/A 10/1963 to present Tunnel near Meeks Bay, Buck Island Reservoir CA 11428300 Buck-Loon Tunnel near Flow that is diverted 6,425 N/A 10/1963 to Meeks Bay, CA from Buck Island to present Loon Lake 11429300 Robbs Peak Powerplant Flow through 4,827 N/A 10/1962 to powerhouse present 11429340 Loon Lake Powerplant Flow through 5,270 N/A 10/1974 to present powerhouse 11440900 Jones Fork Powerplant Flow through 4,870 N/A 10/1984 to powerhouse present 11441002 Union Valley Powerplant Flow through 4,435 N/A 10/1972 to present powerhouse 11441780 Jaybird Powerplant Flow through 2,920 N/A 10/1991 to present powerhouse 11441895 Camino Powerplant Flow through 1,848 N/A 10/1973 to present powerhouse 11443460 White Rock Powerhouse Flow through 990 N/A 3/1972 to present powerhouse 11444280 Rock Creek Powerhouse Flow through N/A 73 10/1/1986 to powerhouse present Reservoir Elevation SMUD Rubicon Reservoir Daily Observation N/A N/A 1993 to present (some earlier record, sporadic) SMUD Buck Island Reservoir Daily Observation N/A N/A 1993 to present (some earlier record, sporadic) 11429350 Loon Lake near Meeks Daily Observation at N/A N/A 12/1963 to present Bay, CA midnight 11429600 Gerle Reservoir near Daily Observation at N/A N/A 10/1990 to present Meeks Bay, CA midnight 11441001 Union Valley Reservoir Daily Observation at N/A N/A 11/1962 to present near Riverton, CA midnight 11441100 Ice House Reservoir near Daily Observation at N/A N/A 10/1959 to present Kyburz, CA midnight 11441760 Junction Reservoir near Daily Observation at N/A N/A SMUD operation Pollock Pines, CA midnight record 1980-91 (sporadic) Published: 10/1991 to present

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Table 3.1-1. (continued) Gage Drainage USGS Elevation Area Number USGS Description Notes (feet) (sq-mi) Period of Record 11441890 Camino Reservoir near Daily Observation at N/A N/A SMUD operation Pollock Pines, CA midnight record 1980-91 (sporadic) Published: 10/1991 to present 11442690 Brush Creek Reservoir Daily Observation at N/A N/A SMUD operation near Pollock Pines, CA midnight record 1980-91 (sporadic) Published: 10/1991 to present 11443450 Slab Creek Reservoir near Daily Observation at N/A N/A SMUD operation Camino, CA midnight record 1975-86 (sporadic) Published: 5/1987 to present PG&E Chili Bar Reservoir Daily Observation, N/A N/A 1/1/1993 to various times present

Precipitation data have also been collected for many points within and adjacent to the UARP. Isohyetal maps describing annual precipitation are available from the Oregon Climate Service. These data were obtained for the UARP and are illustrated in Figure 3.1-1. An area-weighted average precipitation was determined for each watershed and is summarized in Table 3.1-2.

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Figure 3.1-1

Table 3.1-2. Drainage Area and Average Annual Precipitation (as computed by Vestra) Annual Precipitation Drainage Area Area (sq mi) (inches) Rubicon River at Rubicon Reservoir 26.5 55.3 Little Rubicon River at Buck Island Reservoir 6.0 50.1 Gerle Creek at Loon Lake 8.0 44.2 South Fork Rubicon River at Robbs Peak Reservoir 15.2 48.7 Gerle Creek at Gerle Creek Reservoir 30.7 47.5 Silver Creek at Union Valley Reservoir 83.9 49.5 South Fork Silver Creek at Ice House Reservoir 27.3 51.7 Silver Creek at Junction Reservoir 142.6 50.3 Silver Creek at Camino Reservoir 167.1 50.7 Brush Creek at Brush Creek Reservoir 8.0 55.1 South Fork American River at Slab Creek Reservoir Not computed by Vestra Not computed by Vestra South Fork American River at Chili Bar Reservoir Not computed by Vestra Not computed by Vestra

A combination of storage and elevation data was provided by SMUD for the project reservoirs. Reservoir storage data for some project reservoirs is available from the USGS. However, the USGS data for many locations are rounded to the nearest 100 acre-feet, and the unimpaired

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Elevation data and storage-elevation curves using recent bathymetry data collected during 1999- 2000 were provided by SMUD for the Loon Lake and Ice House Reservoir. Storage-elevation relationships used in the analysis are summarized in Table 3.1-3. Storage-elevation data for the combined Gerle Reservoir/Gerle Canal/Robbs Reservoir was also provided by SMUD (Table 3.1-3). Storage-elevation curves developed by SMUD were provided for Rubicon, Buck Island and Union Valley reservoirs and are summarized in Figure 3.1-2. Elevation-area curves were developed from storage-elevation-curves for Rubicon and Buck Island reservoir and are also provided in Figure 3.1-2. Elevation-area curves assumed for Union Valley Reservoir are summarized in Table 3.1.3. Storage data in acre-feet were provided for the remaining regulating reservoirs. Data availability varied by location. Some missing data were estimated by linearly interpolating between days with available data. This technique was only applied when the number of consecutive missing days was less than five except at Rubicon Reservoir where storage data were collected at two to four-week intervals prior to water year 1993.

Table 3.1-3. Elevation-Storage-Area Curves Robbs-Gerle Union Valley Regulation Reservoirs Ice House Reservoir Loon Lake Reservoir Reservoir and Gerle Canal Elevation Storage Area Elevation Storage Area Elevation Area Elevation Storage Acre- Acre- Feet feet Acres Feet feet Acres Feet Acres Feet Acre-feet 5,320 3 2 6,305 - - 4,650 150 5,196 157 5,325 41 10 6,330 2,359 140 4,660 200 5,197 171 5,330 78 18 6,331 2,499 140 4,670 255 5,198 185 5,340 471 65 6,332 2,646 147 4,680 315 5,199 201 5,350 1,407 126 6,333 2,799 153 4,690 380 5,200 217 5,360 3,053 200 6,334 2,957 158 4,700 450 5,201 235 5,370 5,420 271 6,335 3,080 123 4,710 500 5,202 253 5,380 8,439 330 6,336 3,203 123 4,720 580 5,203 273 5,390 12,000 379 6,337 3,582 379 4,730 675 5,204 293 5,400 16,026 426 6,338 3,977 395 4,740 780 5,205 315 5,410 20,537 475 6,339 4,385 408 4,750 890 5,206 338 5,420 25,551 526 6,340 4,809 424 4,760 5,207 362 5,430 31,038 571 6,341 5,246 437 4,770 5,208 387 5,440 36,984 618 6,342 5,699 453 4,780 5,209 413 5,450 43,504 675 6,343 6,165 466 4,790 5,210 441 5,460 50,024 732 6,344 6,647 482 4,800 5,211 470 6,345 7,142 495 4,810 5,212 500 6,346 7,652 510 4,820 5,213 532 6,347 8,176 524 4,830 5,214 565 6,348 8,715 539 4,840 5,215 600

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Table 3.1-3. (continued) Robbs-Gerle Union Valley Regulation Reservoirs Ice House Reservoir Loon Lake Reservoir Reservoir and Gerle Canal Elevation Storage Area Elevation Storage Area Elevation Area Elevation Storage Acre- Acre- Feet feet Acres Feet feet Acres Feet Acres Feet Acre-feet 6,349 9,268 553 4,850 5,216 636 6,350 9,835 567 4,860 5,217 674 6,351 10,417 582 4,870 5,218 713 6,352 11,013 596 5,219 754 6,353 11,623 610 5,220 796 6,354 12,247 624 5,221 840 6,355 12,886 639 5,222 886 6,356 13,539 653 5,223 933 6,357 14,205 666 5,224 983 6,358 14,887 682 5,225 1,034 6,359 15,582 695 5,226 1,086 6,360 16,291 709 5,227 1,141 6,361 17,014 723 5,228 1,197 6,362 17,752 738 5,229 1,254 6,363 18,503 751 5,230 1,316 6,364 19,269 766 5,231 1,378 6,365 20,048 779 6,366 20,842 794 6,367 21,649 807 6,368 22,471 822 6,369 23,306 835 6,370 24,156 850 6,371 25,019 863 6,372 25,896 877 6,373 26,787 891 6,374 27,691 904 6,375 28,610 919 6,376 29,542 932 6,377 30,488 946 6,378 31,448 960 6,379 32,421 973 6,380 33,409 988 6,381 34,409 1,000 6,382 35,424 1,015 6,383 36,452 1,028 6,384 37,494 1,042 6,385 38,549 1,055 6,386 39,618 1,069 6,387 40,701 1,083 6,388 41,797 1,096 6,389 42,907 1,110 6,390 44,030 1,123

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Storage in Acre-feet Rubicon Reservoir = MElev*(-2.8946) + MElev2 * (2.712422) + Melev3 * (-0.013234) + 19 where MElev = Measured Elevation at Rubicon in Feet – 6520

Buck Island Reservoir = Melev*(1.821236) + MElev2 * (.330139) + MElev3 * (0.01243) + 3 where MElev = Measured Elevation at Buck Island in Feet – 6400

Union Valley Reservoir = MElev*(266.02471854) + MElev2 * (-0.7059044574) + MElev3 * (0.0255698466) + MElev4 * (-0.000032551) + MElev5 * (0.0000000419) + 6605.806 where MElev = Measured Elevation at Union Valley in Feet – 4640

Area in Acres Rubicon Reservoir = Maximum (0, or Minimum (Elev*5-32605, or Elev*0.21466-1292.4)) where Elev = Measured Elevation at Rubicon in Feet

Buck Island Reservoir = Maximum (Elev*1.333-8534, or Elev*2.2-14095, or 3.143*Elev – 20155) where Elev = Measured Elevation at Buck Island in Feet

Figure 3.1-2

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An adjustment for net evaporation is made at some Project reservoir release points. Net evaporation rates were developed from pan data collected by SMUD at several locations within the Project area during the seventies. Average monthly “net evaporation” rates were computed based on the collected data. The same monthly adjustment is applied each year regardless of water year type. Monthly net evaporation rates are summarized in Table 3.1-4. Monthly net evaporation data are not available for Rubicon and Buck Island Reservoirs. The values for Loon Lake Reservoir were assumed at both of these locations. Net evaporation was applied at Rubicon, Buck Island, Loon Lake, Ice House and Union Valley reservoirs using the following equation:

Net Evaporation = Reservoir surface area for day (values from Table 3.1-3 or Figure 3.1-2) * Evaporation Rate for month (Table 3.1-4)

Table 3.1-4. Net Evaporation Rates at Various Project Reservoirs Month Loon Lake (Ft/day) Ice House (Ft/day) Union Valley (Ft/day) January 0.000000 0.000000 0.000000 February 0.000000 0.000000 0.000000 March 0.005387 0.001871 0.001871 April 0.007900 0.005067 0.005067 May 0.014097 0.009290 0.009290 June 0.016433 0.014833 0.014833 July 0.021548 0.017903 0.017903 August 0.020194 0.016258 0.016258 September 0.017300 0.011500 0.011500 October 0.008935 0.005419 0.005419 November 0.002433 0.001367 0.001367 December 0.000000 0.000000 0.000000

Maps describing the geological characteristics within the UARP watershed were provided by the United States Department of Agriculture, Forest Service (El Dorado National Forest). These maps are included as figures 3.1-3 through 3.1-5 of this report and describe the following features:

• Figure 3.1-3: Geologic Formations, Sequences and Complexes • Figure 3.1-4: Sedimentary Rocks and Gravels • Figure 3.1-5: Metamorphic and Igneous Rocks

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Figure 3.1-3. Geologic Formations, Sequences and Complexes

Figure 3.1-4. Sedimentary Rocks and Gravels

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Figure 3.1-5. Metamorphic and Igneous Rocks

3.2 Methodology

In general, the unimpaired inflow record was computed by mass balance when sufficient data were available. However, for periods during which a complete record of necessary hydrologic parameters was insufficient to apply a mass balance approach, the unimpaired inflow record was synthesized using streamflow records from nearby watersheds with similar characteristics (e.g., watershed elevation and basin geology). Streamflow gage data from nearby stations used in the analysis are summarized in Table 3.2-1.

Table 3.2-1. Streamflow Gages Adjacent to or Nearby the UARP Gage Drainage USGS USGS Elevation Area Period of Record Number Description (feet) (sq-mi) Blackwood Creek near Tahoe City 10336660 6,240 11.2 10/1/1960 to present (Blackwood) Ward Creek at Hwy 89 near Tahoe Pines 10336676 6,230 9.7 10/1/1972 to present (Ward) 10336780 Trout Creek near Tahoe Valley (Trout) 6,250 36.7 10/1/1960 to present Duncan Creek near French Meadows 11427700 5,270 9.9 10/1/1960 to present (Duncan) 11431800 Pilot Creek above Stumpy Meadows (Pilot) 4,280 11.7 10/1/1960 to present Rock Cr near Placerville, CA (adjusted to 11444201 1,305 73.0 10/1/1986 to present include powerhouse diversions) (Rock)

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Depending upon the available data and quality of computed unimpaired inflow data, different procedures were used to develop the final unimpaired flow data. Because different techniques were sometimes applied, each site is discussed individually.

3.2.1 South Fork Silver Creek at Ice House Reservoir

Ice House Reservoir is located on South Fork Silver Creek. The drainage area above the reservoir is about 27.3 square miles and ranges in elevation from 5,290 to almost 10,000 feet. The watershed is a combination of granite at high elevations and timber area with more developed soils at the lower elevations. The USGS have collected streamflow data on the South Fork Silver Creek since October 1924. The original stream gage was located at the current dam site. After the reservoir was completed in October 1959, the gage was relocated 0.4 mi downstream of the reservoir. The increase in drainage area at the new gage site is about 1 percent.

Since October 1959, this measured flow of the South Fork Silver Creek near Ice House has been regulated by Ice House Reservoir. To compute the unimpaired inflow to Ice House Reservoir, SMUD adjusts this measured flow to account for the change in storage at Ice House Reservoir and net evaporation. Net evaporation over the reservoir surface is based on the surface area at the beginning of the day times monthly evaporation rates (based on average pan evaporation data collected by SMUD during the seventies). The monthly evaporation rates are assumed to be constant for all years.

In 1985, the Jones Fork Powerhouse began operation. With the addition of Jones Fork Powerhouse, flow can bypass the stream gaging station, entering Silver Creek at Union Valley Reservoir. To compute the unimpaired inflow to Ice House Reservoir after 1985, SMUD adjusts the measured flow downstream to account for the powerhouse draft, reservoir storage change and net evaporation. A schematic diagram showing storage, diversions and gaging locations is provided in Figure 3.2.1-1.

The Ice House Reservoir location was selected as the first site to compute unimpaired flow data because of the long period of available daily record and the minimal regulation that occurs upstream of the site. Because of the robust nature of the available information at this location, a technique to synthesize the daily unimpaired inflow record at this location based on streamflow data from nearby gaging stations was developed. The technique was then applied at the remaining basins where data are more limited. Though theoretically sound, and applicable for the Ice House drainage, the technique was not applicable at all Project locations.

Using the historical record, the daily unimpaired inflows to Ice House Reservoir were computed using a mass balance procedure with the information described in Figure 3.2.1-1. Examples of the “computed” unimpaired inflow are provided in figures 3.2.1-2 through 3.2.1-4. The daily unimpaired inflow for water year 1995 is displayed in Figure 3.2.1-2. The annual unimpaired inflow during water year 1995 (wet year) was about 200% of the average annual inflow. Comparable data for water year 1975 are displayed in Figure 3.2.1-3. The annual unimpaired inflow during water year 1975 (average year) was close to the average annual inflow. Water year 1994 is displayed in Figure 3.2.1-4. The annual unimpaired inflow during water year 1994

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(dry year) was about 40% of the average annual inflow. As seen in these figures, the calculation procedure occasionally resulted in computed negative inflows and some large fluctuations. These anomalies were probably due to questionable storage data (i.e., wind and erroneous gage readings). Further refinement was required to adjust these data to eliminate computed negative inflows and to provide some “data smoothing”.

As described before, the drainage basin lies above elevation 5,290 feet. Winter precipitation is in the form of snow and the majority of the annual runoff occurs during the spring months when the snow melts. To synthesize a daily inflow record at this site, recorded daily data from a nearby stream gage site in a basin of similar elevation characteristics is used. The elevation characteristics of the South Fork Silver Creek above the Ice House Reservoir (Ice House) drainage and the characteristics of drainages of nearby gaging stations are displayed in Figure 3.2.1-5.

As seen in Figure 3.2.1-5, none of the nearby drainage basins exactly replicate the elevation characteristics of the Ice House drainage. These nearby drainages are either higher in elevation (resulting in the drainage having snowmelt later into the spring season) or are lower in elevation (resulting in the drainage having an increased winter runoff and a reduced volume of runoff in the spring). A combination of these gages was used to develop a surrogate basin with similar characteristics to the Ice House drainage. First, the elevation data for each drainage basin was evaluated in size (square miles) and combined to create a basin with similar elevation/area characteristics to the Ice House drainage. A simplification of the methodology is provided in Table 3.2.1-1 using two hypothetical drainage basins. In the example provided in Table 3.2.1-1, a “synthetic” basin was created from drainage basins 1 and 2 that has similar elevation characteristics to drainage area A. A coefficient of 2 is applied to drainage basin 1 and 0.5 to drainage basin 2 in order to create a synthesized basin similar to basin A. Additional adjustments to the coefficients are made to compensate for large discrepancies in average annual precipitation characteristics.

Table 3.2.1-1. Evaluation of Drainage Area Elevation Characteristics, An Example Drainage 5,000-5,500 Feet 5,500-6,000 Feet 6,000-6,500 Feet 6,500-7,000 Feet A: To be Estimated 200 300 500 700 Nearby Gaging Stations 1 105 160 0 0 2 0 0 950 1,500 Synthesized 210 320 475 750

This procedure was applied at the Ice House drainage using the sites identified in Figure 3.2.1-5 (Blackwood, Ward, Trout, Duncan and Pilot creek drainages). In a parallel procedure, a multiple regression analysis was performed relating the monthly inflow for Ice House and the flow for all the nearby drainage basins. The regression coefficients computed for the nearby gages by the procedure were very close to the coefficients that had been based upon the elevation/area characteristics.

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The regression equation basically resembles the following equation:

Ice House Monthly Flow (AF) = Coefficient Area A * Area A monthly Flow (AF) plus Coefficient Area B * Area B monthly Flow (AF) plus Constant

The following modification was made to convert the monthly relationship to a daily relationship in cubic feet per second (cfs):

Ice House Daily (cfs) = Coefficient Area A * Area A daily Flow (cfs) plus Coefficient Area B * Area B daily Flow (cfs) plus Constant/60

The factor applied to the constant adjusts for the number of days in a month and a conversion from volume (AF) to cfs. The procedures and coefficients to compute the simulated inflow into Ice House Reservoir are provided in Appendix A.

The area-elevation characteristics of the synthesized basin which is based on the coefficients developed by the multiple regression procedure are displayed in Figure 3.2.1-6, and compares well to the characteristics of the Ice House Reservoir drainage. A comparison of synthesized daily flows for wet year 1995 to computed daily flows are plotted in Figure 3.2.1-7. The black line represents the computed daily inflow for Ice House based on a mass balance of gaged flows and computations. The red line represents the synthesized daily inflow based on the area/elevation and regression procedure. The results of the synthesis are considered to be very good in comparison to the gaged and computation values.

The “computed” monthly data for inflow to Ice House are of high quality, with the exception of some low flows that are discussed in the following section. To improve the synthesized record, the daily data were modified by proportionately adjusting the daily inflow values so that the total synthesized monthly inflow volume is equal to the monthly “computed” inflow volume to Ice House. This was accomplished by applying the following formula:

Adjusted Synthesized Daily Inflow = Synthesized Daily Inflow * Computed Monthly Inflow to Ice House Synthesized Monthly Inflow to Ice House

There still remained a handful of computed negative monthly inflow volumes during low flow periods. The extensive pre-project USGS flow record was utilized to modify these values. The pre- and post-project data were evaluated to depict “carryover flow” conditions during the June through October period. Using both pre- and post-project data, plots (Figure 3.2.1-8) were made of:

• June versus July monthly flow • July versus August monthly flow • August versus September monthly flow • September versus October monthly flow

Using these historical data for guidance, estimates of minimum monthly flows reasonably likely to occur were made. For example, the computed inflow to Ice House reservoir for July 1992, as compared to August 1992, appeared high for a dry year (Figure 3.2.1-8, light blue hatched

Page 20 of 133 SMUD UARP/Study Report/Hydro_redline accepted_42704.doc Pacific Gas and Electric Company Sacramento Municipal Utility District Chili Bar Project Upper American River Project FERC Project No. 2155 FERC Project No. 2101 circle). The simulated flows and computed flows were compared and the computed flow for August through October 1992 appeared too low and the computed flow for July 1992 appeared too high. The computed flow was redistributed between the four months based on the simulated monthly volumes. In most cases, an attempt was made to redistribute the computed volume over the modified period. In the specific case of calendar year 1992, the computed flow volume was reduced by 2.8%.

Comparisons of results for a wet, average and dry year are displayed in figures 3.2.1-9, 3.2.1-10, and 3.2.1-11, respectively. The black line represents the computed daily inflow for Ice House based on a mass balance of gaged flows and computations. The red line represents the synthesized daily inflow based on the area/elevation and regression procedure. The blue line represents the synthesized values which have been adjusted for the monthly computed values. This data set represents the final data values of the analysis.

Changes in gage location, instrumentation and observational procedures may cause a relative change in the computation of flow at a location. Sometimes these changes can be detected by plotting a scatter diagram of annual streamflow comparing two locations. However, these changes can be more easily detected by comparing the accumulated annual record of the two locations. A double-mass analysis evaluates the consistency of the data by comparing one site’s accumulated annual runoff for the period of record with the accumulated annual runoff record from an adjacent location where the data have been already evaluated for consistency. As a final evaluation of the quality of the unimpaired inflow data for the full investigation period (1975- 2001), a consistency (or homogeneity) analysis was performed using a double mass procedure with the unimpaired inflow for the American River at Fair Oaks site, as computed by the Department of Water Resources. Accumulated annual unimpaired inflow to the American River at Fair Oaks plotted against inflow to Ice House Reservoir (double mass diagrams) is provided in Figure 3.2.1-12. The constant slope of the relationship without any significant shift illustrates that the synthesized data appear homogeneous.

A box-whisker plot describing the daily flow characteristics for each month is provided in Figures 3.2.1-13. A box-whisker plot is commonly used to show the minimum, maximum, median, and lower and upper quartile values for a data set. In this case, the box-whisker plot illustrates the characteristics of the daily flow data for a month. The box defines the range of values that is within the lower and upper quartiles of the data, and the line in the center of the box is the median value. The caps extending from the end of each box indicate the extreme values (minimum and maximum) of the data set. The median value represents the data point for which an equal number of values occur above and below. The lower quartile value represents the data point for which 25 percent of the sample will be less than (and 75 percent of the sample will exceed) and the upper quartile represents the data point for with 75 percent of the sample will be less than (and 25 percent of the sample will exceed).

The average annual runoff at Ice House Reservoir is 60,000 acre-feet. A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

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Ice House Watershed and Nearby Vicinity Schematic Diagram Showing Storage,Diversions and Metering Locations

toUnion Valley Power House Junction Reservoir Union Valley Reservoir Silver Creek

Jones Fork to Jaybird Power Plant Power House

Net Evaporation

Ice House Reservoir South Fork Silver Creek near Ice House (instream release and spill) Gaging station

Stream, open flume or canal showing direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.1-1

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1600 Inflow to Ice House Reservoir Computed

1200

800

400 Inflow to Ice House ReservoirInflow in to Ice cfs

-400

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (days)

Figure 3.2.1-2. Inflow to Ice House Reservoir, WY 1995

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1000

Inflow to Ice House Reservoir Computed

800

600

400

Inflow to Ice House Reservoir in cfs House Reservoir Ice to Inflow 200

-200

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (da ys)

Figure 3.2.1-3. Inflow to Ice House Reservoir, WY 1975

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300

200

100 Inflow to Ice House Reservoir in cfs Reservoir House Ice to Inflow

Inflow to Ice House Reservoir Computed

-100

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (da ys)

Figure 3.2.1-4. Inflow to Ice House Reservoir, WY 1994

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100 Ice House 10336660 Blackwood Creek 10336676 Ward Creek 10336780 Trout Creek 11427700 Duncan Creek 11431800 Pilot Ck

40 Drainage Area in Percent of Area Drainage DrainageTotal of Area in Percent

0 <1500 <2000 <2500 <3000 <3500 <4000 <4500 <5000 <5500 <6000 <6500 <7000 <7500 <8000 <8500 <9000 <9500 <1 0000 <1 0500 <1 1000 Contributing Drainag e Area (fe e t) Figure 3.2.1-5. Ice House Reservoir Drainage Area Versus Elevation

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100 Ice House Ice House Es ti ma te d

40 Drainage Area in Percent of Total Drainage Area Drainage Total of Percent in Area Drainage

0 <1500 <2000 <2500 <3000 <3500 <4000 <4500 <5000 <5500 <6000 <6500 <7000 <7500 <8000 <8500 <9000 <9500 <1 0000 <1 0500 <1 1000 Contributing Drainag e Area (fe e t) Figure 3.2.1-6. Ice House Reservoir Drainage Area Versus Elevation For Simulated Data

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1600 Inflow to Ice House Reservoir Computed Synthesized

1200

800

400 Inflow to Ice House Reservoir incfs HouseReservoir Ice to Inflow

-400

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (da ys)

Figure 3.2.1-7. Inflow to Ice House Reservoir, WY 1995

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Silver Creek at Ice House 1

Ice House Reservoir Pre-project 1925-59 96 Post-project 1960-85 Jones Fork PH in Operation 1986-2001 0.8 86 99

64 38 0.6 79 Determine if high inflow 43 due89 to precipitation 41 0 91

36 50 25 84 71 0.4 62

85 97 70 35 45 90 AugustMonthly Flow 1,000 in Acre-feet 87 57 63 88 59 46 0.2 61 49 51 40 1 44 72

55 33 37 39 54 Preferred Range of Expected Flow 28 30 81 47 29 26 77 66 73 34 94 0 31 60 92

01234 July Monthly Flow in 1,000 Acre-feet Figure 3.2.1-8. Silver Creek at Ice House, August Flow Versus July Flow

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1600

1200

800

400 Inflow to Ice House Reservoir in cfs House Reservoir Ice to Inflow

Inflow to Ice House Reservoir Computed Synthesized Synthesized and Adjusted to Monthly Computed -400

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (days)

Figure 3.2.1-9. Inflow to Ice House Reservoir, WY 1995

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1000 Inflow to Ice House Reservoir Computed Synthesized Synthesized and Adjusted to Monthly Computed

800

600

400

Inflow to Ice House Reservoir in cfs House Reservoir Ice to Inflow 200

-200

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (da ys)

Figure 3.2.1-10. Inflow to Ice House Reservoir, WY 1975

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300

200

100 Inflow to Ice House Reservoir in cfs House Reservoir Ice to Inflow

Inflow to Ice House Reservoir Computed Synthesized Synthesized and Adjusted to Monthly Computed -100

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (da ys)

Figure 3.2.1-11. Inflow to Ice House Reservoir, WY 1994

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Double Mass 2000

1500

1000

500

Cummulative Annual Runoff, 75-01 0

SF Silver Ck blw Ice House Reservoir KAF 0 1020304050607080 Cummulative Annual Runoff, 75-01 American River at Fair Oaks MAF (Natural DWR) Figure 3.2.1-12

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SouthSouth Fork Fork Silver Silver Fork Creek at Ice at IceHouse House Reservoir Reservoir WYWY 1975-01 1975-01 10000

1st 3rd Quartile Quartile Minimum Maximum

1000

100

10 Average DailyFlowcfs in

0.1

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.1-13. SF Silver Creek at Ice House Reservoir, Monthly Box-whisker Diagram

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3.2.2 Rubicon River at Rubicon Reservoir

Rubicon Reservoir is located on the Rubicon River. The drainage area is about 26.5 square miles and ranges in elevation from 6,545 to almost 9,500 feet. The watershed is covered by granite. The dam was built in 1963.

Since 1993, SMUD has monitored all water management components required to compute the unimpaired inflow on a daily basis (reservoir storage, diversion through Rubicon-Rockbound Tunnel, instream release and estimated spill). The computed unimpaired inflow was initially calculated for this period of record using a mass balance procedure. The analysis produced several summer months with inflow computed as a negative value, primarily associated with low flow periods. As a means of reducing the number of computed negative values, the daily data were adjusted for net evaporation (Loon Lake net evaporation coefficients were assumed for Rubicon Reservoir). Though the net evaporation is small, about 2 cfs during the summer, in many years it exceeds the actual inflow to the reservoir.

Daily inflows to Rubicon Reservoir were synthesized based on the area/elevation and regression procedure. The method applied to synthesize the unimpaired daily inflows to Rubicon Reservoir is very similar to the technique applied at Ice House. A multiple regression analysis is performed using monthly data for the 1993-2001 period and daily data are developed from the monthly equations. The monthly results appear reasonable, but comparison of daily synthesized flows to “computed” unimpaired flow data for recent years (figures 3.2.2-1 and 3.2.2-2) are only considered to be fair in quality. The black line represents the computed daily inflow for Rubicon Reservoir based on a mass balance of gaged flows and computations. The red line represents the synthesized daily inflow based on the area/elevation and regression procedure.

The daily synthesized values do not replicate the “flashy” daily flow characteristics apparent in the computed flows. The final evaluation of the results demonstrated that the technique developed is best suited when nearby drainage basins exhibit similar soil characteristics. Because Rockbound Valley has extremely low levels of soil development, unlike the nearby drainages, the synthesis procedure did not provide satisfactory results on a daily basis.

To better synthesize a daily record, procedures using all available “in-basin” data were used to estimate the daily unimpaired inflows for the investigation period. The available data over the investigation period varies but can be broken into three periods as described in Table 3.2.2-1.

Table 3.2.2-1. Computed Unimpaired Inflow Data to Rubicon Reservoir Period of Record Quality of unimpaired Flow Estimate and Comments 1993-2001: All components required Best: All data available to compute unimpaired inflow except for spill to compute unimpaired inflow are that was estimated. Short periods of computed negative streamflow monitored (Figure 3.2.2-3) data were smoothed with surrounding data. 1975-1986: Estimated daily record Better: Available data included some change in storage (sporadic), based on computed unimpaired inflow tunnel diversion, and flow at the Rubicon River at Rubicon Springs. at the Rubicon River at Rubicon Sporadic measurements above the reservoir to set the instream release Springs, sporadic monthly storage data flow below the reservoir. In addition to the sporadic storage data, (Figure 3.2.2-4) dates of tunnel settings.

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Table 3.2.2-1. (continued) Period of Record Quality of unimpaired Flow Estimate and Comments 1987-1992: Based on Rubicon- Good: Unimpaired inflow data were based on diversion data and Rockbound diversion and data from estimates of flow below the reservoir. In 1991, a low-flow gage was nearby gages (Figure 3.2.2-5) installed below the reservoir.

Based on review of the records, the only data that are consistently available throughout the investigation period are: (1) the tunnel diversion and (2) the flow below the reservoir (missing data through a dry sequence 1987-1991). To evaluate the quality of computed unimpaired flow estimates based solely on tunnel diversion and flow below the reservoir, the data for the period 1993-2001 was reanalyzed by computing the unimpaired inflow based on the two components only. The two-component computed values were compared to the full-component computed values (i.e., unimpaired flows computed from data for diversion, releases, spill, change in storage and evaporation). The results of the comparison for a wet year and dry year are provided in figures 3.2.2-6 and 3.2.2-7, respectively. The black line represents the computed daily inflow for Rubicon Reservoir based on a mass balance of gaged flows and computations. The blue line represents the synthesized daily inflow based solely on tunnel diversion and flow below the reservoir. As seen on Figure 3.2.2-6, the two-component computation will underestimate the inflow when there is spill or when the reservoir is being filled at the end of the runoff season (highlighted in red). In a dry year (Figure 3.2.2-7) it is apparent (highlighted in red) when the diversion gates are being removed and installed which results in large changes in reservoir storage. Apart from these limited difficulties, using only the diversion and the release below the reservoir provides a very satisfactory estimate of the unimpaired inflow. This conclusion provided the opportunity to develop unimpaired flow information for the 1975-1986 and 1987- 1992 periods when less than a full record of all of the flow components necessary for a mass balance computation is available.

Methodology Applied: 1975-1986

For the 1975-86 period unimpaired flow for the Rubicon River at Rubicon Springs was computed using the USGS gage data at this location. These estimates are improved with the addition of sporadic Rubicon Reservoir storage information, net evaporation and information for the opening and closure dates of the tunnel. The final data are adjusted proportionately by area to estimate the Rubicon River at Rubicon Reservoir:

Rubicon R. at Rubicon Reservoir (flow in cfs) = Rubicon R. at Rubicon Springs (flow in cfs) times Rubicon R. at Rubicon Reservoir drainage area (26.5) divided by Rubicon R. at Rubicon Springs drainage area (31.4)

The flow adjustment described above assumes that the runoff per square mile is about equal for the two drainage basins.

Methodology Applied: 1987-1992

For the 1987-91 period, there are no continuous estimates of releases from Rubicon Reservoir. Thus, these values are estimated from other available data. One source of data is the sporadic

Page 36 of 133 SMUD UARP/Study Report/Hydro_redline accepted_42704.doc Pacific Gas and Electric Company Sacramento Municipal Utility District Chili Bar Project Upper American River Project FERC Project No. 2155 FERC Project No. 2101 measurements above the reservoir that are used to set the reservoir release during the summer months. Another source of information is the results of the synthesis procedure. Although the synthesis procedure using nearby drainage gage data yielded only fair results, the low flow estimates nonetheless provided guidance for estimating flows during the summer months. The results shown in figures 3.2.2-1 and 3.2.2-2, illustrate that the synthesis procedure performed well during the summer months.

By water year 1992, SMUD installed a low flow gage below the reservoir. SMUD has also estimated the spill below Rubicon Reservoir for the period 1992-2001. These unimpaired inflow estimates appear to be very good.

Consistency of Simulated Record: 1975-2001

As a final evaluation of the quality of the unimpaired inflow data for the full investigation period (1975-2001), a consistency (or homogeneity) analysis was performed using the double mass procedure comparing this location’s inflow with the unimpaired inflow data for the South Fork Silver Creek at Ice House Reservoir. The initial double mass plot indicated the period 1975-86 was not consistent with the latter record. The inconsistency is thought to be due to the procedure that calculated the unimpaired flow for the period 1975-86 from the computed unimpaired flow at Rubicon River at Rubicon Springs. Based on the results illustrated in the double mass diagram, the runoff per square mile into the Rubicon Reservoir appears to be greater than the runoff per square mile for the Rubicon River at Rubicon Springs. The adjustment used to develop a consistent record required an increase in the daily unimpaired inflow for the period 1975-1986 by 3 percent:

Another way to interpret the adjustment is that the runoff per square mile is about 3 percent greater for the Rubicon River at Rubicon Reservoir than the Rubicon River at Rubicon Springs. The final double mass diagram is provided in Figure 3.2.2-8.

A box-whisker diagram describing the daily flow characteristics by month is provided as Figure 3.2.2-9. The average annual runoff at Rubicon Reservoir is 79,000 acre-feet. A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

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1200 Inflow to Rubicon Reservoir Computed Synthesized

800

400 Inflowto RubiconReservoir cfs in

-400

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (da ys)

Figure 3.2.2-1. Inflow to Rubicon Reservoir, WY 1995

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500 Inflow to Rubicon Reservoir Computed Synthesized

400

300

200 Inflow to Rubicon toInflow inReservoir cfs 100

-100

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (da ys)

Figure 3.2.2-2. Inflow to Rubicon Reservoir, WY 1994

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1993 - Present Inflow to Rubicon Reservoir Schematic Diagram Showing Storage,Diversions and Metering Locations

Estimated Net Evaporation (Loon Lake monthly rates) Gaged flow (low Rubicon River flows only) Rubicon Reservoir spill estimated by Reservoir SMUD Diversions to Rockbound Lake

Gaging station

Stream, open flume or canal showing direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.2-3

1975 - 1986 Inflow to Rubicon Reservoir Schematic Diagram Showing Storage,Diversions and Metering Locations

Rubicon Estimated Net Reservoir at Evaporation (Loon Rubicon Springs Lake monthly rates) Rubicon Reservoir data Rubicon River (31.4 sq mi) Rubicon were weekly/monthly. Reservoir Information provided on dates gates were opened and closed. Flow computed at Rubicon Diversions to Reservoir at Rubicon Rockbound Also sporadic summer Lake measurements of inflow Springs, adjusted for area to used to set release represent at Rubicon below reservoir.

Reservoir. Adjusted again Gaging station by 3% (increase) based on Stream, open flume or canal showing double mass. direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.2-4

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1987 - 1992 Inflow to Rubicon Reservoir Schematic Diagram Showing Storage,Diversions and Metering Locations

Estimated Net Gage below Evaporation (Loon reservoir starting WY Lake monthly rates) 1992 Rubicon River Rubicon Sporadic estimates of summer Reservoir inflow measurements through 1991 used to estimate release Diversions to below reservoir. Some elevation Rockbound data available from prelimnary Lake diversion records (stage).

Gaging station

Stream, open flume or canal showing direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.2-5

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1200

800

400 Inflowto RubiconReservoir cfs in

Inflow to Rubicon Reservoir Computed (Change in storage, release, evaporation, diversion, spill) Inflow Computed Based on Diversion and Release only

-400

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (days)

Figure 3.2.2-6. Inflow to Rubicon Reservoir, WY 1995

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600

400

200 Inflow to RubiconReservoir in cfs

Inflow to Rubicon Reservoir Computed (Change in storage, release, evaporation, diversion, spill) Inflow Computed Based on Diversion and Release only

-200

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (days)

Figure 3.2.2-7. Inflow to Rubicon Reservoir, WY 1994

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Double Mass 2500

2000

1500

1000 Thousands Rubicon AF

500

0 0 500 1000 1500 2000 Ice House AF Thousands Figure 3.2.2-8

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Rubicon River at Rubicon Reservoir WY 1975-01 10000 1st 3rd Quartile Quartile Minimum Maximum Median

1000

100

10 Average DailyFlowcfs in

0.1

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.2-9. Rubicon River at Rubicon Reservoir, WY 1975-01, Monthly Box-whisker Diagram

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3.2.3 Little Rubicon River at Buck Island Reservoir

Buck Island Reservoir is located on the Little Rubicon River. The drainage area is about 26.5 square miles and ranges in elevation from 6,440 to almost 9,500 feet. The watershed is covered by granite. The dam was built in 1963.

As with the Rubicon Reservoir system, SMUD has, since 1993, monitored all water management components required to compute the unimpaired inflow on a daily basis (reservoir storage, diversion through Rubicon-Rockbound Tunnel, instream release and estimated spill). The computed unimpaired inflow was calculated using a mass balance procedure. An initial analysis resulted in the inflow being computed as a negative value in several summer months, primarily associated with low flow periods. As a means of reducing the number of computed negative values, the daily data were adjusted for net evaporation (Loon Lake net evaporation coefficients were assumed for Buck Island Reservoir). Though the net evaporation is small, about 1 cfs during the summer, in many years it exceeds the actual inflow to the reservoir.

Available data for the site are summarized in Table 3.2.3-1.

Table 3.2.3-1. Computed Unimpaired Inflow Data to Buck Island Reservoir Period of Record Use in Computing Unimpaired Inflow 1993-2001: All components required Best: All data available to compute unimpaired inflow (estimated spills). to compute unimpaired inflow are Short periods of computed negative streamflow data were smoothed with monitored (Figure 3.2.3-1) surrounding data. Diversions into the basin are lagged for 12 hours1. 1975-1992: Estimated daily record Good: It was determined that the same procedure used on the Rubicon includes diversions in and out of will be applied at Buck Island. The unimpaired inflow is be estimated as: basin (Figure 3.2.3-2) • Diversions out of the basin • Diversions into the basin (lagged by 12 hours)1 plus • Estimate of net evaporation plus • Estimate of instream release (1 cfs) 1Based on conversations with SMUD staff

Using the same approach applied to the Rubicon River, the daily inflow was estimated from the available “in-basin” data. Because a record for the full complement of water management components is not available for the entire period of investigation, an analysis was performed to evaluate the validity of computing inflow values from the partial information. This was accomplished by taking the data for the full-component period (1993-2001) and computing the inflow based on the water management components available for the 1975-1992 period (i.e., difference in diversions in and out of the basin). The partial-component computed values are then compared with the full-component computed values (including diversions, release and spill, change in storage and evaporation) for the period 1993-2001. Results of the comparison for a dry year, wet year and flood event are provided in figures 3.2.3-3 through 3.2.3-5, respectively. The black line represents the computed daily inflow for Buck Island Reservoir based on a mass balance of gaged flows and computations. The blue line represents the synthesized daily inflow based solely on partial-component data.

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As seen in these figures, the partial-component computational procedure will underestimate the inflow when there is spill (Figure 3.2.3-5) or when the reservoir is being filled at the end of the runoff season. During the summer months the inflows are estimated to be too high because the instream release was made from water in storage. Daily unimpaired flow estimates for the Rubicon River at Rubicon Reservoir were used to refine values for the spill and summer flow periods. For example, the computed inflow to Buck Island Reservoir for the month of July 1990 was greater than expected since the instream release more than likely was made from storage. These data would require adjustment. To make the adjustment, the inflow to Buck Island Reservoir was re- estimated using the daily inflow to Rubicon Reservoir (Rubicon Reservoir inflow multiplied by 0.2033 to adjust for differences in area). Next, these daily estimates were compared to Buck Island daily flows. The Buck Island computed flows were replaced with the estimate made using the Rubicon Reservoir inflow data. This procedure was not built into the spreadsheet but performed by hand checking each month and day.

Unimpaired inflow data for this site were tested for consistency (or homogeneity) for the investigation period 1975 through 2001 through a comparison to the unimpaired inflow for the South Fork Silver Creek at Ice House, and are illustrated in Figure 3.2.3-6. The data appear homogenous.

A box-whisker diagram describing the daily flow characteristics by month is provided as Figure 3.2.3-7. The average annual runoff at Buck Island Reservoir is 22,000 acre-feet. A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

1993-2001 Little Rubicon Watershed and Nearby Vicinity Schematic Diagram Showing Storage,Diversions and Metering Locations

Rubicon River Diversions from Estimated Net Rubicon River Evaporation (Loon Little Lake monthly rates) Rubicon Low flows River only, SMUD estimated spills Buck Island Rockbound Reservoir Lake

Loon Lake Reservoir

Gaging station

Stream, open flume or canal showing direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.3-1

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1975-1992 Little Rubicon Watershed and Nearby Vicinity Schematic Diagram Showing Storage,Diversions and Metering Locations

Rubicon River Diversions from Rubicon River Estimated Net Little Evaporation (Loon Rubicon Lake monthly rates) River Buck Island Rockbound Reservoir Lake

Loon Lake Reservoir

Gaging station

Stream, open flume or canal showing direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.3-2

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150

100

0 Inflow to Island Reservoir Buck in cfs

-50

Inflow to Buck Island Reservoir Computed Inflow based on diversions and estimated reservoir release -100

1 0 /1 /9 3 1 1 /1 / 9 3 1 2 / 1 /9 3 1 / 1 /9 4 2 /1 / 94 3 /1 / 9 4 4/ 1 /9 4 5 /1 / 9 4 6 / 1 /9 4 7 /1 /9 4 8 / 1/ 9 4 9/ 1 /9 4 1 0 / 1 /9 4 Time (days)

Figure 3.2.3-3. Inflow to Buck Island Reservoir, WY 1994

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600 In fl ow to Buc k Is la nd Re servoi r Computed Inflow based on diversions and estimated reservoir release

400

200 Inflow to IslandBuck Reservoir in cfs

-200

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (da ys)

Figure 3.2.3-4. Inflow to Buck Island Reservoir, WY 1995 (on the x-axis, the plot runs from October 1, 1994 through October 1, 1995)

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2000 Infl ow to Buc k Is lan d Reservoi r 1600 Computed Inflow based on diversions 1200 and estimate of reservoir release

800

400

200

160

120

0 Inflow to Island Reservoir Buck incfs

-40

-80

-120

-160

-200

1 0 /1 /9 6 1 1 /1 / 9 6 1 2 / 1 /9 6 1 / 1 /9 7 2 /1 / 97 3 /1 / 9 7 4/ 1 /9 7 5 /1 / 9 7 6 / 1 /9 7 7 /1 /9 7 8 / 1/ 9 7 9/ 1 /9 7 1 0 / 1 /9 7 Time (days)

Figure 3.2.3-5. Inflow to Buck Island Reservoir, WY 1997 (on the x-axis, the plot runs from October 1, 1996 through October 1, 1997)

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Double Mass 700

600

500

400

300 Thousands

Buck Island AF 200

100

0 0 500 1000 1500 2000 Ice House AF Thousands Figure 3.2.3-6

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Little Rubicon River at Buck Island WY 1975-01 10000 1st 3rd Quartile Quartile Minimum Maximum

1000

100

10 Average DailyFlowcfs in

0.1

0.01

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.3-7. Little Rubicon River at Buck Island, WY 1975-01, Monthly Box-whisker Diagram

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3.2.4 Gerle Creek and South Fork Rubicon River

There are four computation nodes for the Gerle Creek and South Fork Rubicon River (SFRR) elements of the UARP (figures 3.2.4-1 and 3.2.4-2):

• Gerle Creek at Loon Lake Reservoir • Gerle Creek at Gerle Reservoir • South Fork Rubicon River at Robbs Peak Diversion Dam • SFRR below Gerle Creek near Georgetown (validation point only)

The Gerle Creek drainage area at Loon Lake Dam is 8.0 square miles and ranges in elevation from 6,410 to over 7,500 feet. The watershed is primarily granite rock. The present dam was built in 1963.

The Gerle Creek drainage area at Gerle Creek Dam is 30.7 square miles and ranges in elevation from 5,230 to over 8,000 feet. The watershed is a combination of granite and timber area with more developed soils. The facility was completed in 1962.

The SFRR drainage area at Robbs Peak Diversion Dam is 15.2 square miles and ranges in elevation from 5,230 to almost 9,000 feet. The watershed is a combination of granite and timber area with more developed soils. The facility was completed in 1962. SMUD monitors the combined releases at Gerle Creek Reservoir and Robbs Peak Diversion Dam and also estimates the spill at these sites. The combined flow from the Gerle-Robbs drainage (excluding inflow to Loon Lake) has been computed by SMUD on a daily basis since 1993.

The final node is the USGS gage located on the SFRR downstream of Gerle Creek. The gage was installed in 1961 and has a drainage area of about 47.7 square miles. The station name is SFRR below Gerle Creek near Georgetown.

The analysis started at the headwaters of the Gerle Creek drainage at Loon Lake Reservoir. Sufficient data are available to compute the unimpaired inflow to the reservoir using a mass balance procedure. Though the watershed is high in elevation, and it might be expected that the winter/spring flow pattern would be similar to the Rubicon or Little Rubicon rivers, 30% of the drainage area is covered by lake surface which significantly affects the seasonal inflow pattern. Examples of the computed inflow are provided in figures 3.2.4-3 through 3.2.4-5. These figures illustrate that there are large fluctuations in these data that require smoothing. In addition, some of the low flows during the summer and fall months appear inconsistent when compared to inflows on the Rubicon and Little Rubicon rivers.

To smooth the large data fluctuations and adjust the questionable data, seasonal “smoothing” procedures were applied. During the winter months, computed daily inflow values are adjusted to be the two-day rolling average of values. This procedure produced good results without overly “smoothing out” high flow events. During the summer months where flows normally have less variability, the computed daily inflow values are adjusted to represent a three- to five-day rolling average of values, always attempting to smooth the flows and remove computed negative values.

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An example of the impact of the adjustments is illustrated in Figure 3.2.4-6 (smoothed). The black line represents the computed daily inflow for Loon Lake based on a mass balance of gaged flows and computations. The red line represents the smoothed daily inflow.

Despite the smoother unimpaired inflow estimates, large inflow fluctuations were still of concern. Therefore, a second estimate of inflow to Loon Lake was developed that is dependent on the computed unimpaired inflow for the SFRR below Gerle Creek. The unimpaired inflow at this location is computed for the investigation period using a mass balance procedure. The data also required some smoothing, and an additional adjustment was made based on the inflow estimates to the Silver Creek at Union Valley Reservoir. A comparison of the computed and estimated (smoothed) daily flow values for the SFRR below Gerle Creek is provided in figures 3.2.4-7 through 3.2.4-9. The black line represents the computed daily flow for SFRR below Gerle Creek based on a mass balance of gaged flows and computations. The blue line represents the smoothed flows.

The SFRR below Gerle Creek unimpaired flow data were tested for consistency (or homogeneity) by comparing these data to the unimpaired inflow for the South Fork Silver Creek at Ice House (Figure 3.2.4-10). These data appear homogenous.

Following completion of the SFRR below Gerle Creek daily flow estimates, the second Loon Lake inflow data set was derived as a percentage of the total flow (estimated based on the drainage area):

Loon Lake inflow = 0.155254 * SFRR below Gerle Creek

This Loon Lake inflow estimate (SFRR Estimate) was compared with the initial computed flow for Loon Lake. The final daily values were based on an equal percentage of the smoothed- computed values and the SFRR Estimate.

Loon Lake inflow = 0.5 * (0.155254 * SFRR below Gerle Creek + computed smooth Loon Lake estimate)

Figures 3.2.4-11 through 3.2.4-13 compare the initial computed and the final daily flows for a wet, average and dry year, respectively. The black line represents the computed daily flow for SFRR below Gerle Creek based on a mass balance of gaged flows and computations. The red line represents the final synthesized flows.

A box-whisker diagram describing the Loon Lake monthly unimpaired daily flow characteristics is provided as Figure 3.2.4-14. The average annual runoff at Loon Lake is 20,000 acre-feet. A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

The combined unimpaired inflow to Gerle Creek Reservoir and the SFRR flow into Robbs Peak Diversion Dam is referred to hereinafter as the Gerle-Robbs drainage. The full complement of water management components required to compute the unimpaired inflow for Gerle-Robbs has not been monitored over the entire investigation period. However, there are sufficient data to compute the unimpaired inflow to Gerle-Robbs using a mass balance procedure for the period 1993 through 2001.

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A second estimate of unimpaired inflow to Gerle-Robbs was computed based on the unimpaired inflow to the SFRR below Gerle Creek for the same period, 1993-2001. The values were computed as follows:

Remaining Flow = SFRR below Gerle Creek – Loon Lake inflow (computed previously)

Accretions to Gerle Creek Reservoir = 0.572077 * Remaining Flow

SF Rubicon inflow to Robbs Peak Diversion Dam = 0.384073 * Remaining Flow

Unregulated flow above USGS gage = SFRR below Gerle Creek – Loon Lake inflow – Accretions to Gerle Creek Reservoir - SF Rubicon inflow to Robbs Peak Diversion Dam

The unimpaired inflow to Gerle-Robbs using both procedures is displayed graphically in figures 3.2.4-15 and 3.2.4-16 for a wet and a dry year, respectively. The black line represents the computed daily flow for Gerle-Robbs below Gerle Creek based on a mass balance of gaged flows and computations. The blue line represents the synthesized flows. The estimate of unimpaired inflow to Gerle-Robbs based on the unimpaired flow of SFRR below Gerle Creek appeared quite satisfactory and therefore this procedure is used to estimate the unimpaired inflow to Gerle-Robbs for the remaining investigation period, 1975-1992. Figure 3.2.4-17 is a plot of the synthesized inflow to Robbs-Gerle for water year 1975. The total inflow for water year 1975 is close to the average annual flow for the investigation period.

A box-whisker diagram describing the monthly unimpaired daily flow characteristics for Gerle Creek at Gerle Creek Reservoir and SFRR at the Robbs Peak Diversion Dam are displayed in figures 3.2.4-18 and 3.2.4-19, respectively. The average annual runoff at Gerle Creek at Gerle Creek Reservoir is 54,000 acre-feet and the average annual runoff at SFRR at the Robbs Peak Diversion Dam is 50,000 acre-feet. A table of monthly runoff at these sites for the period 1975- 2001 is included in Appendix B.

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Figure 3.2.4-1

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Loon/Gerle/Robbs Watershed and Nearby Vicinity Schematic Diagram Showing Storage,Diversions and Metering Locations

South Fork Rubicon below Gerle Creek Buck-Loon Tunnel Estimated Robbs Release and net Peak Spill evaporation Power Gerle Creek Plant Gerle Loon Lake Robbs Reservoir Reservoir DD Gerle Canal Loon Lake Power Plant

South Fork Rubicon River

SMUD monitors Robbs & Gerle release and estimates spill. Gaging station Stream, open flume or canal showing direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.4-2

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800 Inflow to Loon Lake Reservoir Computed

600

400 Inflow in cfs

200

-200

1 0 /1 /9 4 1 1 /1 / 9 4 1 2 / 1 /9 4 1 / 1 /9 5 2 /1 / 95 3 /1 / 9 5 4/ 1 /9 5 5 /1 / 9 5 6 / 1 /9 5 7 /1 /9 5 8 / 1/ 9 5 9/ 1 /9 5 1 0 / 1 /9 5 Time (days)

Figure 3.2.4-3. Inflow to Loon Lake Reservoir, WY 1995

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120 Inflow to Loon Lake Reservoir Computed

40 Inflow in cfs

-40

1 0 /1 /9 3 1 1 /1 / 9 3 1 2 / 1 /9 3 1 / 1 /9 4 2 /1 / 94 3 /1 / 9 4 4/ 1 /9 4 5 /1 / 9 4 6 / 1 /9 4 7 /1 /9 4 8 / 1/ 9 4 9/ 1 /9 4 1 0 / 1 /9 4 Time (days)

Figure 3.2.4-4. Inflow to Loon Lake Reservoir, WY 1994

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800

400

0 Inflow in cfs

-400

Inflow to Loon Lake Reservoir Computed

-800

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (da ys)

Figure 3.2.4-5. Inflow to Loon Lake Reservoir, WY 1975

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120 Inflow to Loon Lake Reservoir Computed Smoothed

40 Inflow in cfs

-40

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (da ys)

Figure 3.2.4-6. Inflow to Loon Lake Reservoir, WY 1994

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4000 SF Rubicon blw Gerle Ck Computed Smoothed

3000

2000 Flow in cfs

1000

-1000

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (da ys)

Figure 3.2.4-7. SF Rubicon below Gerle Creek, WY 1995

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400 SF Rubicon blw Gerle Ck Computed Smoothed

300

200 Fl ow in cfs

100

-100

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (da ys)

Figure 3.2.4-8. SF Rubicon below Gerle Creek, WY 1994

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1600

SF Rubicon blw Gerle Ck Computed Smoothed

1200

800 Flow in cfs

400

-400

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (da ys)

Figure 3.2.4-9. SF Rubicon below Gerle Creek, WY 1975

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Double Mass 3000

2500

2000

1500

Thousands 1000

Loon, Robbs & Gerle AF 500

0 0 500 1000 1500 2000 Ice House AF Thousands Figure 3.2.4-10

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800 Inflow to Loon Lake Reservoir Computed Fi nal

600

400 Inflow in cfs

200

-200

1 0 /1 /9 4 1 1 /1 / 9 4 1 2 / 1 /9 4 1 / 1 /9 5 2 /1 / 95 3 /1 / 9 5 4/ 1 /9 5 5 /1 / 9 5 6 / 1 /9 5 7 /1 /9 5 8 / 1/ 9 5 9/ 1 /9 5 1 0 / 1 /9 5 Time (da ys)

Figure 3.2.4-11. Inflow to Loon Lake Reservoir, WY 1995

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800

400

0 Inflow in cfs

-400

Inflow to Loon Lake Reservoir Computed Final

-800

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (da ys)

Figure 3.2.4-12. Inflow to Loon Lake Reservoir, WY 1975

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120 Inflow to Loon Lake Reservoir Computed Final

40 Inflow in cfs

-40

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (da ys)

Figure 3.2.4-13. Inflow to Loon Lake Reservoir, WY 1994

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Gerle Creek at Loon Lake WY 1975-01 10000 1st 3rd Quartile Quartile Minimum Maximum

1000

100

10 Average DailyFlowcfs in

0.1

0.01

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.4-14. Gerle Creek at Loon Lake, WY 1975-01, Monthly Box-whisker Diagram

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4000 Gerle - Robbs Computed Estimated

3000

2000 Flow i n cfs

1000

-1000

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (da ys)

Figure 3.2.4-15. Gerle – Robbs, WY 1995

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300 Gerle - Robbs Computed Estimated

200

100 Flow in cfs

-100

1 0 /1 /9 3 1 1 /1 / 9 3 1 2 / 1 /9 3 1 / 1 /9 4 2 /1 / 94 3 /1 / 9 4 4/ 1 /9 4 5 /1 / 9 4 6 / 1 /9 4 7 /1 /9 4 8 / 1/ 9 4 9/ 1 /9 4 1 0 / 1 /9 4 Time (days)

Figure 3.2.4-16. Gerle – Robbs, WY 1994

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1000

Gerle - Robbs Estimate

800

600 Fl ow in cfs

400

200

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (da ys)

Figure 3.2.4-17. Gerle – Robbs, WY 1975

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Gerle Creek at Gerle Creek Reservoir WY 1975-01 10000

1st 3rd Quartile Quartile Minimum Maximum

1000

100

10 Average DailyFlowcfs in

0.1

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.4-18. Gerle Creek at Gerle Creek Reservoir, WY 1975-01, Monthly Box-whisker Diagram

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South Fork Rubicon River at Robbs Peak WY 1975-01 10000

1st 3rd Quartile Quartile Minimum Maximum

1000

100

10 Average DailyFlow cfs in

0.1

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.4-19. SF Rubicon River at Robbs Peak, WY 1975-01, Monthly Box-whisker Diagram

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3.2.5 Silver Creek at Union Valley Reservoir

Union Valley Reservoir is located on Silver Creek. The drainage area is about 83.9 square miles and ranges in elevation from 4,870 to 8,500 feet. The watershed is a combination of granite in the upper reaches of the watershed with timber area and better developed soils at the lower elevations. The unimpaired inflow to Union Valley Reservoir is provided from three primary tributary streams: Tells Creek, Big Silver Creek, and Jones Fork Silver Creek.

The USGS began collecting streamflow data on Silver Creek at Union Valley in October 1924. The original gage was located at the location of the current dam site. The gage was removed in 1960 during the construction of the dam. The reservoir was completed in 1962. Since 1962, the flow of Silver Creek is regulated by Union Valley Reservoir and receives diversions from the Rubicon River, by Robbs Peak Powerhouse. To compute the local unimpaired inflow to Union Valley Reservoir, SMUD adjusts the measured flow on Silver Creek to account for the change in Union Valley Reservoir storage, net evaporation, reservoir spill and diversions into the basin. Spill from the reservoir has been estimated by SMUD staff.

In April of 1985, Jones Fork Powerhouse was completed. With the addition of the powerhouse, flow was diverted from the South Fork of Silver Creek into Union Valley Reservoir. A schematic of the system is provided in Figure 3.2.5-1.

Daily data are available to compute the unimpaired inflow into Union Valley Reservoir for the entire investigation period using a mass balance procedure. Examples of the “computed” unimpaired flow are provided in figures 3.2.5-2 through 3.2.5-4. As seen in these figures, the computation resulted in some computed negative inflows and large daily fluctuations. These daily fluctuations are probably due to questionable storage data (i.e., wind and erroneous readings). The data inconsistencies were modified through a combination of professional judgment and a comparative review of pre- and post-project flow relationships between Silver Creek at Union Valley and the South Fork Silver Creek at Ice House. An example of the modified daily inflow is provided in figures 3.2.5-5 through 3.2.5-7. The black line represents the computed daily flow for Silver Creek at Union Valley based on a mass balance of gaged flows and computations. The final smoothed data are displayed in blue.

Unimpaired inflow data for the site were tested for consistency (or homogeneity) for the investigation period 1975 through 2001 through a comparison to the unimpaired inflow for the South Fork Silver Creek at Ice House, and appear as Figure 3.2.5-8. The data appear homogenous.

A box-whisker diagram describing the daily flow characteristics by month is provided as Figure 3.2.5-9. The average annual runoff at Union Valley Reservoir is 179,000 acre-feet. A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

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Inflow to Union Valley Reservoir and Nearby Vicinity Schematic Diagram Showing Storage,Diversions and Metering Locations (Present)

Union Valley Power House (discretionary and/or instream Estimated net release). Spill must be estimated evaporation for each event by SMUD. Diversion from Rubicon River Junction Reservoir Union Valley Reservoir Basin Silver Creek

Jones Fork to Jaybird Power Plant Power House

Ice House Reservoir South Fork Silver Creek near Ice House (instream release and spill) Gaging station

Stream, open flume or canal showing direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.5-1

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5000 Union Valley Computed

4000

3000

2000 Flow in cfs

1000

-1000

1 0 /1 /9 4 1 1 /1 / 9 4 1 2 / 1 /9 4 1 / 1 /9 5 2 /1 / 95 3 /1 / 9 5 4/ 1 /9 5 5 /1 / 9 5 6 / 1 /9 5 7 /1 /9 5 8 / 1/ 9 5 9/ 1 /9 5 1 0 / 1 /9 5 Time (days)

Figure 3.2.5-2. Union Valley, WY 1995

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2000

Union Valley Computed

1000 Flow in cfs

-1000

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (da ys)

Figure 3.2.5-3. Union Valley, WY 1975

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800

600

400 Flow in cfs

200

Union Valley Computed

-200

1 0 /1 /9 3 1 1 /1 / 9 3 1 2 / 1 /9 3 1 / 1 /9 4 2 /1 / 94 3 /1 / 9 4 4/ 1 /9 4 5 /1 / 9 4 6 / 1 /9 4 7 /1 /9 4 8 / 1/ 9 4 9/ 1 /9 4 1 0 / 1 /9 4 Time (da ys)

Figure 3.2.5-4. Union Valley, WY 1994

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5000 Union Valley Computed Smoothed

4000

3000

2000 Flow i n cfs

1000

-1000

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (da ys)

Figure 3.2.5-5. Union Valley, WY 1995

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800

600

400 Flow in cfs

200

Union Valley Computed Smoothed -200

1 0 /1 /9 3 1 1 /1 / 9 3 1 2 / 1 /9 3 1 / 1 /9 4 2 /1 / 94 3 /1 / 9 4 4/ 1 /9 4 5 /1 / 9 4 6 / 1 /9 4 7 /1 /9 4 8 / 1/ 9 4 9/ 1 /9 4 1 0 / 1 /9 4 Time (da ys)

Figure 3.2.5-6. Union Valley, WY 1975

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2000

Union Valley Computed Smoothed

1000 Flow in cfs

-1000

1 0 /1 /7 4 1 1 /1 / 7 4 1 2 / 1 /7 4 1 / 1 /7 5 2 /1 / 75 3 /1 / 7 5 4/ 1 /7 5 5 /1 / 7 5 6 / 1 /7 5 7 /1 /7 5 8 / 1/ 7 5 9/ 1 /7 5 1 0 / 1 /7 5 Time (da ys)

Figure 3.2.5-7. Union Valley, WY 1994

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Double Mass 6

3 Millions 2 Union Valley AF

0 0 500 1000 1500 2000 Ice House AF Thousands Figure 3.2.5-8

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Silver Creek at Union Valley Reservoir WY 1975-01 100000

1st 3rd Quartile Quartile Minimum Maximum

10000

1000

100 Average DailyFlowcfs in

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.5-9. Silver Creek at Union Valley Reservoir, WY 1975-01, Monthly Box-whisker Diagram

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3.2.6 Silver Creek at Camino Reservoir Including Brush Creek

The lower Silver Creek drainage, downstream of Union Valley Reservoir, contains three computation nodes with respect to the UARP (Figure 3.2.6-1):

• Silver Creek at Junction Reservoir • Silver Creek at Camino Reservoir • Brush Creek at Brush Creek Reservoir

The Silver Creek drainage area at Junction Reservoir Dam is 142.6 square miles and ranges in elevation from 4,450 to almost 10,000 feet. This drainage includes the South Fork Silver Creek, as well as the primary drainages upstream of Union Valley Reservoir. The watershed is a combination of granite and timber area with well developed soils. Construction of the dam was completed in 1962. SMUD has monitored or estimated all of the flow management components required to compute the unimpaired inflow since 1993.

The Silver Creek drainage area at Camino Reservoir is 167.1 square miles and ranges in elevation from 2,920 to almost 10,000 feet. The watershed is a combination of granite and timber area with well developed soils. Construction of the dam was completed in 1961.

The Brush Creek drainage area at Brush Creek Reservoir is 8.0 square miles and ranges in elevation from 2,920 to almost 5,000 feet. The drainage area is covered with timber and has well developed soils. Construction of the dam was completed in 1961. Brush Creek Tunnel connects Brush Creek Reservoir with the lower end of Camino Tunnel. The Brush Creek Tunnel allows water to flow to and from the Camino Tunnel to Brush Creek Reservoir. The flow through the Brush Creek Tunnel is not monitored so it is only possible to compute the combined unimpaired flow for the Silver Creek at Camino Reservoir and Brush Creek at Brush Creek Reservoir. Daily data have been monitored since 1993.

The process of computing unimpaired flow at each of the three UARP nodes required a series of analytical steps that consist of combining drainages throughout the basin, then disaggregating them. The first step consisted of estimating the combined unimpaired inflow at Camino Reservoir and Brush Creek Reservoir. This portion of the inflow estimate incorporates the total accretion that enters Silver Creek downstream of Union Valley Reservoir and Ice House Reservoir. Flows upstream of these reservoirs are not factored into this initial step of the analysis. Thus, this portion of the inflow estimate incorporates accretions from all sources including major tributaries below Ice House Reservoir (e.g., Big Hill Creek) as well as inflows downstream of Union Valley (e.g., Little Silver Creek, Onion Creek). The portion of the combined estimate dealing with Brush Creek consists of the total unimpaired inflow to Brush Creek Reservoir. Once an estimate of the combined unimpaired flow is derived, the second step of the process is to disaggregate the accretion values into the three separate drainages.

The combined unimpaired inflow of Silver Creek at Camino Reservoir (excluding flow above Union Valley Reservoir and Ice House Reservoir) plus Brush Creek at Brush Creek Reservoir is computed from a mass balance procedure for the investigation period. Examples of the

Page 86 of 133 SMUD UARP/Study Report/Hydro_redline accepted_42704.doc Pacific Gas and Electric Company Sacramento Municipal Utility District Chili Bar Project Upper American River Project FERC Project No. 2155 FERC Project No. 2101 computed data are provided in figures 3.2.6-2 through 3.2.6-4. As seen from these figures, there are many computed negative flows and large daily fluctuations. Some of these anomalies are attributable to the combined unimpaired inflow often being relatively small compared to the volume of water passing through both powerhouses (Union Valley and Camino). Errors in the measurement of these large powerhouse flows can easily be greater than the computed unimpaired flow. Also, the investigation period has several years of missing storage records and extended periods of missing records for the draft through the Camino Powerhouse. To overcome the problems associated with the computed flow, a procedure was developed to synthesize the inflows for the investigation period in order to validate or adjust the computed inflows.

Because the Junction-Camino-Brush drainage basins do not have similar elevation characteristics, the flow synthesis procedure for the drainage area are analyzed as two components, each with their own elevation characteristics:

• Brush Creek at Brush Creek Reservoir • Silver Creek at Camino Reservoir (excluding flow above Union Valley Reservoir and Ice House Reservoir)

The following describes the analysis performed for each of these drainage areas and the additional analysis required to disaggregate the second component into accretions to Junction Reservoir and accretions to Camino Reservoir.

As described previously, the Brush Creek drainage is relatively low in elevation and receives the majority of its annual precipitation in the form of rain. Several USGS low elevation sites were considered for use in the synthesis process, but only three were ultimately applied:

• Rock Creek near Placerville (adjusted for the Rock Creek Powerplant near Placerville), period of record 1986-present • Pilot Creek above Stumpy Meadows, 1960-present • Forest Creek near Wilseyville, 1960-present

The Rock Creek station was selected due to its proximity to the UARP and similar basin elevation characteristics. Despite the fact that the Rock Creek drainage is nearby the Brush Creek drainage, the runoff production per square mile is much less than Brush Creek. A more significant limitation with the Rock Creek data is the fact that the period of record does not cover the full investigation period. To overcome the period of record limitation, the Rock Creek data have been extended with the aid of the Pilot and Forest creek data.

Both the Pilot Creek and Forest Creek stations were evaluated as data sources for extending the Rock Creek data (figures 3.2.6-5 and 3.2.6-6). However, the Pilot Creek drainage is significantly higher in elevation, leading to poor correlation results when the data are compared on a daily basis, leading to the conclusion that Pilot Creek data are of limited value in extending the Rock Creek daily record.

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Daily and monthly flow data of Rock Creek and Forest Creek are much more strongly correlated, resulting in the use of the Forest Creek data to extend the Rock Creek record. Then, using annual data (not the daily data) from Pilot Creek, a relationship was developed between Rock Creek and Pilot Creek to evaluate the extended data. If the annual sum of the daily extended flows varied significantly from the expected volume, the data were adjusted. Relationships used to extend the record are summarized in Appendix C.

Once the Rock Creek data were extended, the inflow into Brush Creek Reservoir was estimated. Based on estimates performed by SMUD, the average annual runoff into Brush Creek Reservoir is about 14,000 acre-feet. The daily inflow into Brush Creek is estimated as follows:

Inflow to Brush Creek Reservoir (cfs) = Rock Creek daily flow times * 0.2684

Unimpaired inflow data for the site were tested for consistency (or homogeneity) for the investigation period 1975 through 2001 through comparison with the unimpaired inflow at the American River at Fair Oaks, and appears as Figure 3.2.6-7. The data appear homogenous.

The second component of the Junction-Camino-Brush drainages is the Silver Creek at Camino location (excluding flow above Union Valley Reservoir and Ice House Reservoir). The process of estimating the accretion in this drainage area began with use of the historical USGS gage record. Prior to the construction of the UARP, the USGS maintained a gage on Silver Creek just above the confluence of the South Fork American River (Silver Creek near Placerville). The drainage area was estimated to be 177 square miles, which is just 6 square miles downstream of the present Camino Reservoir. Also, there were USGS gages at the current approximate locations of Union Valley Reservoir Dam on Silver Creek and Ice House Reservoir on the South Fork Silver Creek. An estimate of accretion between the two upper gages and the mouth of Silver Creek was derived by subtracting the flow at the upstream gages from the downstream gage, explained as the following equation:

Silver Creek at Placerville = Silver Creek near Placerville minus Excluding flow above South Fork Silver Creek near Ice House minus Union Valley Reservoir Silver Creek at Union Valley and Ice House Reservoir (Adjusted Silver Creek near Placerville)

Next, data from nearby gaging stations were used to develop monthly relationships with the computed Adjusted Silver Creek near Placerville. The two sites used were:

• Pilot Creek near Georgetown, and • Silver Creek at Union Valley

Both sites were discontinued prior to the investigation period. However, Pilot Creek near Georgetown was replaced with Pilot Creek near Stumpy Meadows (located upstream of the Georgetown gage) and unimpaired flow of Silver Creek at Union Valley was a computation node in this analysis (see Section “Silver Creek at Union Valley”). The Pilot Creek gage was used to synthesize the winter/spring period (figures 3.2.6-8 and 3.2.6-9) and the Silver Creek to

Page 88 of 133 SMUD UARP/Study Report/Hydro_redline accepted_42704.doc Pacific Gas and Electric Company Sacramento Municipal Utility District Chili Bar Project Upper American River Project FERC Project No. 2155 FERC Project No. 2101 synthesize the summer/fall period (Figure 3.2.6-10). Relationships were developed from the monthly values shown in the plots. Because the earlier gages have been relocated, the points used to develop the relationships were transformed to represent the current gage location Relationships used to extend the record are summarized in Appendix C.

Daily flows have been synthesized for the investigation period at the following two sites:

• Brush Creek at Brush Creek Reservoir • Silver Creek at Camino (excluding flow above Union Valley Reservoir and Ice House Reservoir)

Data were summed for the two drainage areas and compared to the original computed data (figures 3.2.6-11 through 3.2.6-13). The black line represents the computed daily inflow based on a mass balance of gaged flows and computations. The red line represents the synthesized daily inflow. Synthesized data have been used for the period 1975-1992 (red line). For the period 1993-2001, the synthesized daily data have been used but have been proportionately adjusted on a daily basis to equal the monthly volume of computed inflow based on the USGS record. The results of an example of these adjustments are shown in figures 3.2.6-11 and 3.2.6- 13. Upon further review of the data, additional modification was made to finalize the daily data while maintaining the monthly volumes (blue line). A double mass diagram using these data are provided in Figure 3.2.6-14, Double Mass Diagram.

After creating the final data set, “Silver Creek at Camino excluding flow above Union Valley Reservoir and Ice House Reservoir” was disaggregated into two components:

• Accretions to Junction Reservoir (referred to as Area A) • Accretions to Camino Reservoir

As described previously, SMUD has computed the daily inflow to Area A and accretions to Camino Reservoir plus the Brush Creek inflow (Area B) since 1993. To disaggregate the synthesized “Silver Creek at Camino excluding flow above Union Valley Reservoir and Ice House Reservoir” into Area A and accretions to Camino Reservoir the following relationships were developed using the computed data:

• Area A plus Area B minus the synthesized Brush Creek Inflow (combined accretions to Junction and Camino only) • Area A (accretions to Junction)

The synthesized flow was disaggregated and synthesized flows for Area A and Area B estimated. The results were compared to the computed flows for Area A and Area B for the 1993-2001 period. Relationships used to extend the record are summarized in Appendix C. Results for water years 1995, 2000 and 1994 are displayed for Area A and Area B in figures 3.2.6-15 through 3.2.6-20.

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The computed accretions for the drainages above Union Valley Reservoir and Ice House Reservoir are then added to the components of accretion for the Junction and Camino locations. A box-whisker diagram describing the daily flow characteristics by month has been prepared for:

• Silver Creek at Junction Reservoir (Figure 3.2.6-21) • Silver Creek at Camino Reservoir (Figure 3.2.6-22) • Brush Creek inflow to Brush Creek Reservoir (Figure 3.2.6-23)

The average annual runoff is estimated as: • Silver Creek at Junction Reservoir: 295,500 acre-feet • Silver Creek at Camino Reservoir: 335,600 acre-feet • Brush Creek inflow to Brush Creek Reservoir: 14,200 acre-feet

A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

UARP Project Schematic Diagram Showing Storage,Diversions and Metering Locations (1993-2001)

Union Valley Spillt Junction Union Valley Diversion Reservoir Reservoir from Rubicon Jones Union Fork Valley Power Power Plant Plant Jaybird Power Plant South Fork Ice House Brush Creek Camino Silver Creek Reservoir Reservoir Reservoir

Camino Power Slab Creek Plant South Fork American River Reservoir El Dorado El Dorado Power Plant White Rock to EID Canal, Power Diversion to Plant El Dorado Power Plant and EID

Gaging station

Stream, open flume or canal showing direction of flow. Penstock, tunnel, closed flume, or pipe showing direction of flow. Figure 3.2.6-1

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6000 Camino, Junction & Brush Computed

4000

2000 Flow in cfs

-2000

1 0 /1 /9 4 1 1 /1 / 9 4 1 2 / 1 /9 4 1 / 1 /9 5 2 /1 / 95 3 /1 / 9 5 4/ 1 /9 5 5 /1 / 9 5 6 / 1 /9 5 7 /1 /9 5 8 / 1/ 9 5 9/ 1 /9 5 1 0 / 1 /9 5 Time (days)

Figure 3.2.6-2. Camino, Junction and Brush, WY 1995

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1600 Camino, Junction & Brush Computed

1200

800

400 Flow in cfs

-400

-800

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (da ys)

Figure 3.2.6-3. Camino, Junction and Brush, WY 1975

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250 Camino, Junction & Brush Computed

200

150

100 Flow in cfs

-50

1 0 /1 /9 3 1 1 /1 / 9 3 1 2 / 1 /9 3 1 / 1 /9 4 2 /1 / 94 3 /1 / 9 4 4/ 1 /9 4 5 /1 / 9 4 6 / 1 /9 4 7 /1 /9 4 8 / 1/ 9 4 9/ 1 /9 4 1 0 / 1 /9 4 Time (days)

Figure 3.2.6-4. Camino, Junction and Brush, WY 1994

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1986-2001 July Daily Flow in cfs 30

5 Forest Creek near Wilseyville 0 0 50 100 150 Rock Ck near Placerville (ajusted for Rock Ck Powerplant near Placerville) Figure 3.2.6-5

1986-2001 January Daily Flow in cfs 500

400

300

200

100 Forest or Pilot Creek 0 0 200 400 600 800 1000 Rock Ck near Placerville (adjusted for Rock Ck Powerlant near Placerville)

Forest Creek near Wilseyville Pilot Ck above Stumpy Meadows

Figure 3.2.6-6

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Double Mass 1500

1000

Thousands 500 Rock Creek 1000 af

0 0 1020304050607080 American River @ Folsom million af Millions Figure 3.2.6-7

1951-57 January Daily Flow in cfs 2500

2000

1500

1000

500

Adjusted Silver Cr near Placerville 0 0 50 100 150 200 250 300 350 Pilot Ck near Georgetown

Adjusted Silver Creek near Placerville: Silver Creek near Placerville minus South Fork Silver Creek near Ice House and Silver Creek at Union Valley

Figure 3.2.6-8

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1951-1957 April Daily Flow in cfs 1000

800

600

400

200

Adjusted Silver Ck near Placerville 0 0 50 100 150 200 250 300 Pilot Ck near Georgetown

Adjusted Silver Creek near Placerville: Silver Creek near Placerville minus South Fork Silver Creek near Ice House and Silver Creek at Union Valley

Figure 3.2.6-9

1951-1957 Aug Daily Record in cfs 120

100

20 Adjusted Silver Creek near Placerville 0 0 50 100 150 200 Silver Creek at Union Valley

Adjusted Silver C reek near Placerville: Silver Creek near Placerville m inus South Fork Silver Creek near Ice House and Silver Creek at Union Valley

Figure 3.2.6-10

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5000

4000

3000

2000 Fl ow incfs

1000

Camino, Junction & Brush Computed Estimated (sythesized daily and proportioned to USGS monthly) Estimated Final -1000

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (days)

Figure 3.2.6-11. Camino, Junction and Brush, WY 1995

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1600 Camino, Junction & Brush Computed Synthesized data

1200

800

400 Fl ow incfs

-400

-800

10/1/74 11/1/74 12/1/74 1/1/75 2/1/75 3/1/75 4/1/75 5/1/75 6/1/75 7/1/75 8/1/75 9/1/75 10/1/75 Time (days)

Figure 3.2.6-12. Camino, Junction and Brush, WY 1975

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300

200

100 Fl ow incfs

Camino, Junction & Brush Computed Estimated (sythesized daily and proportioned to USGS monthly) Estimated Final

-100

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (days)

Figure 3.2.6-13. Camino, Junction and Brush, WY 1994

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Double Mass Final 3500

3000

2500 Final Data 2000 Unadj Data 1500 Thousands 1000 Junc, Cam, Brush AF 500

0 0 500 1000 1500 2000 Ice House AF Thousands Figure 3.2.6-14

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3000

Junction (Area A) Computed Estimated

2000

1000 Fl ow incfs

-1000

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (days)

Figure 3.2.6-15. Junction (Area A), WY 1995

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1200

Junction (Area A) Computed Estimated

800

400 Fl ow incfs

-400

10/1/99 11/1/99 12/1/99 1/1/00 2/1/00 3/1/00 4/1/00 5/1/00 6/1/00 7/1/00 8/1/00 9/1/00 10/1/00 Time (days)

Figure 3.2.6-16. Junction (Area A), WY 2000

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160 Junction (Area A) Computed Estimated

120

80 Fl ow incfs

-40

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (days)

Figure 3.2.6-17. Junction (Area A), WY 1994

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2000 Area B Computed Estimated

1500

1000 Fl ow in cfs

500

-500

1 0 /1 /9 4 1 1 /1 /9 4 12 /1 / 94 1 / 1/ 95 2 /1 /9 5 3/ 1/ 9 5 4 /1 /9 5 5/ 1/ 9 5 6 /1 /9 5 7/ 1 /9 5 8 /1 /9 5 9/ 1 /9 5 1 0/ 1/ 9 5 Time (days)

Figure 3.2.6-18 Area B, WY 1995

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2000 Ar ea B Computed Estimated

1500

1000 Fl ow incfs

500

-500

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (days)

Figure 3.2.6-19. Area B, WY 2000

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1200

Area B Computed Estimated

800

400 Fl ow incfs

-400

10/1/99 11/1/99 12/1/99 1/1/00 2/1/00 3/1/00 4/1/00 5/1/00 6/1/00 7/1/00 8/1/00 9/1/00 10/1/00 Time (days)

Figure 3.2.6-20. Area B, WY 1994

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Silver Creek at Junction Reservoir WY 1975-01 100000

10000

1000

100 Average DailyFlowcfs in

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.6-21. Silver Creek at Junction Reservoir, WY 1975-01, Monthly Box-Whisker Diagram

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Silver Creek at Camino Reservoir WY 1975-01 100000

10000

1000

100 Average DailyFlowcfs in

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.6-22. Silver Creek at Camino Reservoir, WY 1975-01, Monthly Box -Whisker Diagram

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Brush Creek at Brush Creek Reservoir WY 1975-01 10000

1000

100

10 Average DailyFlowcfs in

0.1

0.01

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.6-23. Brush Creek at Brush Creek Reservoir, WY 1975-01, Monthly Box-whisker Diagram

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3.2.7 South Fork American River at Slab Creek Reservoir

The drainage area of the South Fork American River at Slab Creek Reservoir is about 493 square miles and ranges in elevation from 1,850 to almost 10,000 feet. The watershed is a combination of granite and timber area with well developed soils. Construction of the dam was completed in 1967.

The “natural” SFAR inflow to Slab Creek Reservoir represents the unimpaired inflow to Slab Creek Reservoir absent the effects of both Project 184 and the Upper American River Project (UARP). Daily flows for the SFAR below Akins Powerhouse, excluding Silver Creek, were prepared by Hydrologics as part of the relicensing effort of Project 184. Daily data were extended by ECORP to include the period of investigation in March 2004.

The unimpaired inflow to Slab Creek Reservoir represents the inflow to the reservoir absent the effects the UARP only (SFAR is the proposed regulation of Project 184). EID has provided regulated flow data for the SFAR below Akins, excluding Silver Creek, for the proposed operation of Project 184. The regulated flow assumes that Project 184 will be operated under the terms identified in the EID April 30, 2003 relicensing settlement agreement. This includes an import to the South Fork American River of water from Echo Lake and consumptive water withdrawals from the El Dorado Forebay reservoir. The data were prepared by Hydrologics as part of the relicensing effort of Project 184. Daily data were extended by ECORP to include the period of investigation in March 2004.

The inflow to Slab Creek Reservoir is made up of three components:

• Silver Creek above Camino Diversion Dam (computed by SMUD and detailed in this report) • South Fork American River (SFAR) below Akins Powerhouse (computed by ECORP) • Accretions between Akins Powerhouse and Slab Creek Reservoir (estimated at 2.3 times the inflow to Brush Creek Reservoir)

A box-whisker diagram describing the daily flow characteristics by month is provided in Figure 3.2.7-1. The average annual runoff at Slab Creek Reservoir is 768,400 acre-feet (1975-2001). A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

The “natural” SFAR inflow to Slab Creek Reservoir represents the unimpaired inflow to Slab Creek Reservoir absent the effects of both Project 184 and the Upper American River Project (UARP). Daily flows for the SFAR at El Dorado Powerhouse, excluding Silver Creek, were prepared by Hydrologics as part of the relicensing effort of Project 184. Daily data are available for the water year period 1975 through 1996.

A box-whisker diagram describing the daily flow characteristics by month is provided in Figure 3.2.7-2. The average annual runoff at Slab Creek Reservoir is 783,100 acre-feet (1975-2001). A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

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Unregulated SFAR Inflow to Slab Creek Reservoir (SFAR Regulated for Proposed Operation of P184, Silver Creek Unregulated) WY 1975-01 100000 1st 3rd Quartile Quartile Minimum Maximum

10000

1000 Average DailyFlow cfs in

100

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.7-1. Unregulated SFAR Inflow to Slab Creek Reservoir (SFAR Regulated for P184, Silver Creek Unregulated) WY 1975-01, Monthly Box-whisker Diagram

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Na tu r al SFAR In fl o w to Sl ab Cr ee k Re se rvo i r (Both P184 & Silver Creek Unregulated) WY 1975-01 100000

1st 3rd Quartile Quartile Minimum Maximum

10000

1000 Average Daily Flow in cfs

100

Oct N ov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.7-2. Natural SFAR Inflow to Slab Creek Reservoir (Both P184 & Silver Creek Unregulated) WY 1975-96, Monthly Box-whisker Diagram

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3.2.8 South Fork American River at Chili Bar Reservoir

The inflow to Chili Bar Reservoir is made up of two components:

• SFAR inflow to Slab Creek Reservoir • Accretions between Slab Creek Reservoir and Chili Bar Reservoir (Chili Bar accretions)

For the SFAR inflow to Slab Cree Reservoir, two estimates of inflow are computed:

• Unimpaired SFAR inflow to Slab Creek Reservoir • Natural SFAR inflow to Slab Creek Reservoir

The unimpaired inflow to Slab Cree Reservoir represents the inflow to the reservoir absent the effects the UARP only (SFAR is the proposed regulation of Project 184). The “natural” SFAR inflow to Slab Creek Reservoir represents the unimpaired inflow to Slab Creek Reservoir absent the effects of both Project 184 and the Upper American River Project (UARP).

The drainage area of the SFAR at Chili Bar Reservoir is about 598 square miles and ranges in elevation from 931 (at the stream gage below the reservoir) to almost 10,000 feet. The drainage area of the SFAR between Chili Bar Reservoir and Slab Creek Reservoir, as computed by SMUD consultant Vestra is 104 square miles. The total watershed is comprised a combination of granite and timber area with well developed soils.

Sufficient data are available to compute the unimpaired Chili Bar accretions on a daily basis. The results for a wet, average and dry year are displayed in figures 3.2.8-1, 3.2.8-2 and 3.2.8-3, respectively. As seen from these figures, there are many computed negative flows and large daily fluctuations. Some of these apparent anomalies are attributable to the unimpaired inflow often being relatively small compared to the volume of water reported as passing through both powerhouses (White Rock and Chili Bar). The errors in measurement of large flows through these powerhouses can easily be greater than the computed unimpaired flow. To overcome the problems associated with the computed flow, a procedure was developed to synthesize the inflows for the investigation period in order to validate or refine the computed inflows. The data were checked for homogeneity (Figure 3.2.8-4). The data were not considered to be homogeneous for the entire period of record. It is hypothesized that this may be due to a change in flow determination methods over the duration of the evaluation period (installation of an Acoustical Velocity Meter (AVM) at White Rock Powerhouse in 1993).

Analyses were performed to make the flow estimates consistent. The first analysis performed was the evaluation of the flow data from White Rock Powerhouse (WRP). WRP was completed in 1968. The WRP draft is based on generation-discharge curves from 1968 through 1992. In August 1992, SMUD installed an AVM to measure the WRP draft. A daily analysis was created to evaluate the WRP measured efficiency before and after the AVM was installed. Daily generation data are only available for the period 1978 through 1991 (pre-AVM).

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The results of the WRP generation analysis are illustrated in Figure 3.2.8.5. Unit efficiency for the pre-AVM period is displayed in red and the post-AVM period is displayed in black. As seen in the figure, the efficiency “dropped” after the AVM was installed. This circumstance is likely an indication the flow through the unit was underestimated prior to installation of the AVM. After reviewing the results provided in Figure 3.2.8-5, an adjustment was made to the generation data for the pre-AVM period. Volume adjustments varied between 0% and 18% of the annual draft.

Data for the period 1978 through 1991 were adjusted and the accretions to Chili Bar Reservoir recomputed. Representative examples of the impact to the computation of unimpaired accretions are provided in figures 3.2.8-6 and 3.2.8-7. The results of this first procedure are displayed in red (WR draft) and the previously computed inflow is displayed in black (computed). As seen in these figures, there still remained computed negative flows and large daily fluctuations. However, the annual and monthly volumes had been adjusted.

A second procedure was performed to simulate daily flows through a method that included the use of the unimpaired daily record from a gaging station within the drainage basin (Rock Creek near Placerville). The gage at Rock Creek near Placerville has existed since water year 1987. Rock Creek enters the SFAR between Slab Creek and Chili Bar Reservoirs. The drainage area at the Rock Creek gage is estimated to be 73 square miles. This drainage area is approximately 70 percent of the total drainage area between Slab Creek Reservoir and Chili Bar Reservoir.

The major limitation with the Rock Creek data was that the period of record did not cover the full investigation period. To overcome the period of record limitation, the Rock Creek data was extended with the aid of the Pilot and Forest creek data. The extension of the Rock Creek data is discussed in section “Silver Creek at Camino Reservoir Including Brush Creek”.

Assuming the observed average annual Chili Bar accretions for the period 1993 to 2001 are representative, the Rock Creek data were multiplied by a factor to compute the same average for the 1993 to 2001 period. The daily Chili Bar accretions were estimated as follows:

Estimated Chili Bar Accretions (cfs) = Rock Creek daily flow times Chili Bar Accretions 1993-01 annual average (108,805 AF) divided by Rock Creek 1993-01 annual flow average (64,203 AF)

Representative results of the procedures are displayed in figures 3.2.8-8 and 3.2.8-9 (estimate Chili Bar accretions in blue). A double mass diagram is displayed in Figure 3.2.8-10.

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5000 SFAR Accretions: Slab Ck Res. to Chili Bar Res. Computed

4000

3000

2000 Fl ow in cfs

1000

-1000

10/1/94 11/1/94 12/1/94 1/1/95 2/1/95 3/1/95 4/1/95 5/1/95 6/1/95 7/1/95 8/1/95 9/1/95 10/1/95 Time (days)

Figure 3.2.8-1. SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1995

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3000

2000

1000 Fl ow in cfs

SFAR Accretions: Slab Ck Res. to Chili Bar Res. Computed

-1000

10/1/99 11/1/99 12/1/99 1/1/00 2/1/00 3/1/00 4/1/00 5/1/00 6/1/00 7/1/00 8/1/00 9/1/00 10/1/00 Time (days)

Figure 3.2.8-2. SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 2000

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800 SFAR Accretions: Slab Ck Res. to Chili Bar Res. Computed

400 Fl ow in cfs

-400

10/1/93 11/1/93 12/1/93 1/1/94 2/1/94 3/1/94 4/1/94 5/1/94 6/1/94 7/1/94 8/1/94 9/1/94 10/1/94 Time (days)

Figure 3.2.8-3. SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1994

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Double Mass Water Year Data 1975-2001

1500

1000

Thousands AVM installed in 1993. Data Prior to 1993 are not 500

Accrections Chili Bar - AF homogeneous with pre-1993 data.

0 1020304050607080

American River Inflow to Folsom (AF) Millions Figure 3.2.8-4

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White Rock Powerhouse Computed Efficiency Pre and Post - Acoustical Velocity Meter Measurement

1.00

0.90

0.80

0.70

0.60

0.50

Efficiency in Decimal 0.40

0.30

0.20 Flow - post 92 vs Efficiency, post-92 Flow -pre 92 vs Efficiency - pre 92

0.10

0.00 0 500 1000 1500 2000 2500 3000 3500 4000 Flow in cfs

Figure 3.2.8-5

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6000

SFAR Accretions: Slab Ck Res. to Chili Bar Res. Computed Revised WR Draft

4000

2000 Fl ow in cfs

-2000

10/1/79 11/1/79 12/1/79 1/1/80 2/1/80 3/1/80 4/1/80 5/1/80 6/1/80 7/1/80 8/1/80 9/1/80 10/1/80 Time (days)

Figure 3.2.8-6. SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1980

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3000

SFAR Accretions: Slab Ck Res. to Chili Bar Res. Computed Revised WR Draft

2000

1000 Fl ow in cfs

-1000

10/1/78 11/1/78 12/1/78 1/1/79 2/1/79 3/1/79 4/1/79 5/1/79 6/1/79 7/1/79 8/1/79 9/1/79 10/1/79 Time (days)

Figure 3.2.8-7. SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1979

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6000 SFAR Accretions: Slab Ck Res. to Chili Bar Res. Computed Estimated Revised WR Draft

4000

2000 Fl ow in cfs

-2000

10/1/79 11/1/79 12/1/79 1/1/80 2/1/80 3/1/80 4/1/80 5/1/80 6/1/80 7/1/80 8/1/80 9/1/80 10/1/80 Time (days)

Figure 3.2.8-8. SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1980

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3000

SFAR Accretions: Slab Ck Res. to Chili Bar Res. Computed Estimated Revised WR Draft

2000

1000 Fl ow in cfs

-1000

10/1/78 11/1/78 12/1/78 1/1/79 2/1/79 3/1/79 4/1/79 5/1/79 6/1/79 7/1/79 8/1/79 9/1/79 10/1/79 Time (days)

Figure 3.2.8-9. SFAR Accretions: Slab Creek Reservoir to Chili Bar Reservoir, WY 1979

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Double Mass Water Year Data 1975-2001

3000

2500

2000

1500 Thousands

1000 Accrections Chili Bar - AF

500

0 1020304050607080

American River Inflow to Folsom (AF) Millions Figure 3.2.8-10

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Unregulated SFAR Inflow to Chili Bar Reservoir (SFAR Regulated for Proposed Operation of P184, Silver Creek Unregulated) WY 1975-01 100000

1st 3rd Quartile Quartile Minimum Maximum

10000

1000 Average Daily Flow in cfs

100

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.8-11. Unregulated SFAR Inflow to Chili Bar Reservoir (SFAR Regulated for P184, Silver Creek Unregulated) WY 1975-01, Monthly Box-Whisker Diagram

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N a tu ra l S FAR In fl ow to C h il i B a r Re se rvo i r (Both P184 & Silver C reek U nregulated) WY 1975-01 100000 1st 3rd Quartile Quartile Minimum Maximum

10000

1000 Average Daily Flow in cfs

100

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Figure 3.2.8-12. Natural SFAR Inflow to Chili Bar Reservoir (Both P184 & Silver Creek Unregulated) WY 1975-96, Monthly Box-Whisker Diagram

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These data were added to the two estimates for the SFAR inflow to Slab Creek Reservoir. Total flow was computed for the two conditions:

• Unimpaired SFAR inflow to Chili Bar Reservoir • Natural SFAR inflow to Chili Bar Reservoir

A box-whisker diagram describing the daily flow characteristics by month is provided in Figure 3.2.8-11. The average annual “unimpaired” runoff at Chili Bar Reservoir is 857,900 acre-feet (1975-2001). A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

A box-whisker diagram describing the daily flow characteristics by month is provided in Figure 3.2.8-12. The average annual runoff “natural” at Chili Bar Reservoir is 872,700 acre-feet (1975- 2001). A table of monthly runoff at this site for the period 1975-2001 is included in Appendix B.

4.0 ACCRETIONS

Points where accretions are computed were selected by the Water Balance Subcommittee on October 8, 2003. The locations and the procedures to compute the accretions are summarized in Appendix D. Accretions data are provided on the attached disk.

4.1 Computation of Daily Accretions

Flow at forty-one locations was computed on a daily basis. This group of forty-one locations was further segregated into regulated and unregulated locations. A location existing below a reservoir would be considered regulated. A location above a reservoir, which is not impacted by diversions into the basin or regulated inflow from an upstream facility, would be considered to be unregulated. Regulated locations are described in Table 4.1-1. Unregulated locations are described in Table 4.1-2.

To compute the daily accretions for sub-areas, the computed unimpaired flows described in Section 3.0 of this report were proportionately distributed by drainage sub-area and precipitation. Procedures to compute these daily accretions are summarized in Appendix D. The computed daily accretions at the 41 locations are provided on the attached disk.

Table 4.1-1. Daily Accretions: Regulated Location Points Node Identification on October Description 8, 2003 Memo Rubicon 4 Rubicon River at Rubicon Springs Rubicon 5 Rubicon River below Miller Creek Rubicon 6 Rubicon River below Little Rubicon River Rockbound 1 Rockbound Lake release to Buck Island Reservoir Loon 4 Gerle Creek below Jerrett Creek Loon 5 Gerle Creek below Barts and Dellar Creek Loon 6 Gerle Creek Inflow Above Rocky Basin Creek Loon 7 Gerle Creek below Rocky Basin Creek Loon 8 Gerle Creek Inflow to Gerle Reservoir

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Table 4.1-1. (continued) Node Identification on Description October 8, 2003 Memo Gerle 4 Gerle Creek above Confluence with SF Rubicon River Gerle 5 SF Rubicon above Confluence with Rubicon River Gerle Other (additional point SF Rubicon River below Gerle Creek near Georgetown (USGS Gage, added by SMUD after 1143000) October 8, 2003) Ice House 4 SF Silver Creek below Peavine Creek Ice House 5 SF Silver Creek below Windmiller Ravine Ice House 6 SF Silver Creek below Big Hill Canyon Ice House 7 SF Silver Creek at Junction Reservoir Junction 4 Silver Creek below Grey Horse Creek Junction 5 Silver Creek below Onion Creek Junction 6 Silver Creek below Sugar Pine Creek Junction 7 Silver Creek at Camino Reservoir Camino 3 Silver Creek below Round Tent Canyon Camino 4 Silver Creek Halfway, no name creek Camino 5 Mouth of Silver Creek Brush 4 Brush Creek Inflow to Slab Creek Reservoir Slab 4 SF American River below Iowa Canyon Creek Slab 5 SF American River above Mosquito Road Bridge Slab 6 SF American River below Rock Creek Slab 7 SF American River Above Chili Bar Reservoir

Table 4.1-2. Daily Accretions: Unregulated Location Points Node Identification on Description October 8, 2003 Memo 1 Rubicon River Inflow to Rubicon Reservoir 2 Highland Creek Inflow to Rockbound Reservoir 3 Ellis Creek Inflow to Loon Lake 4 SF Rubicon Inflow to Robbs Peak Reservoir 5 SF Silver Creek Inflow to Ice House Reservoir 6 Tells Creek Inflow to Union Valley Reservoir 7 Big Silver Creek Inflow to Union Valley Reservoir 8 Jones Fork Silver Creek Inflow to Union Valley Reservoir 9 Little Silver Creek Inflow to Junction Reservoir 10 Slab Creek Inflow to Slab Creek 11 Iowa Canyon above SF American River 12 Rock Creek above SF American River

4.2 Computation of Monthly Accretions

Sufficient data to estimate daily accretions for several locations was not available. These locations are described in Table 4.2-1. The procedures applied to estimate the monthly accretions at these points below Chili Bar Reservoir are summarized in Appendix D. Accretions data have been provided on the attached disk.

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Table 4.2-1. Monthly Accretions: Regulated Location Points Node Identification on Description October 8, 2003 Memo Chili Bar 4 SF American River below Dutch Creek Chili Bar 5 SF American River below Greenwood Chili Bar 6 SF American River below Weber Creek

Rock Creek flow data, adjusted for average annual precipitation and drainage area were the basis for estimating the monthly flow record for the three sites. Accretions for each of these locations have minimal regulation with the exception of Weber Creek. El Dorado Irrigation District (EID) was contacted regarding the operation of Weber Reservoir and the diversions on the Farmers Free Ditch and Crawford Ditch. EID is currently in negotiations regarding the new operation of the reservoir. EID has not provided comments regarding the proposed operations at this time. Data provided in the data set for Weber Creek are unimpaired.

5.0 FLOW STATISTICS

To illustrate the difference between unregulated flow at a location and Project regulated flow, comparison tables were prepared for the regulated and unregulated flow condition. The Indicators of Hydrologic Alteration (IHAs) methodology, as described by Richter et al. (1996), was applied. Richter suggests that the hydrologic attributes of a stream can be described by five fundamental groups of statistics. These five groups are:

• Group #1: Magnitude of monthly water conditions • Group #2: Magnitude and duration of annual extreme water conditions • Group #3: Timing of annual extreme water conditions • Group #4: Frequency and duration of high and low pulses • Group #5: Rate and frequency of change in water conditions

IHA values were computed in accordance with Richter et al. (1991) and the Nature Conservancy (2001). As recommended by Richter, all data are presented as non-parametric (percentile) statistics due to the highly skewed nature of hydrologic data sets. In general, the median flow (that flow for which 50 percent of the recorded flows are less than it and 50 percent are greater than it) is used as a measure of central tendency for the IHA value. The spread between the 25th percentiles (that flow for which 25 percent of the recorded flows are less than it and 75 percent are greater than it) and the 75th percentile (that flow for which 75 percent of the recorded flows are less than it and 25 percent are greater than it) divided by the median is a measure of dispersion called the coefficient of dispersion (CD). The median and CD would correspond to the mean and standard deviation in parametric statistics, which is used for data sets that are not so highly skewed. To express the difference between regulated and unregulated statistics, Richter’s deviation factor (unregulated value minus the regulated value divided by the unregulated value) was calculated for both medians and CDs. For medians, the deviation factor may range from a negative value (which indicates that regulated flows are greater than unregulated flows), to zero (which indicates no difference between the regulated and unregulated flows) to a value of one (which indicates regulated flow is approaching zero). For CDs, the

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As also recommended by Richter, IHA statistics should normally be calculated at locations where measured hydrology data are available for about 30 years from both the pre-project and project period. This analysis differed from this approach in two ways. First, the period of record for this relicensing effort is the 26-year period from October 1974 through September 2000, rather than 30 years. Second, pre-project data are only available for a limited number of project points. Therefore, computed unregulated data will be utilized instead.

The analysis was performed at the locations described in Table 5.0-1. The following provides a summary of the parameters evaluated.

Table 5.0-1. IHA Analysis: Locations Analyzed Unregulated Regulated Gerle Creek below Loon Lake Reservoir 4295 Gerle Ck below Loon Lake Dam South Fork Rubicon Below Gerle Creek 4300 South Fork Rubicon Below Gerle Creek 4415 South Fork Silver Creek below Ice House South Fork Silver Creek below Ice House Reservoir Reservoir Silver Creek at Camino Diversion Dam 4419 Silver Creek below Camino Diversion Dam South Fork American River at Slab Creek Reservoir , (unregulated flow, WY75-01) 4435 South Fork American River Near Camino South Fork American River at Slab Creek Reservoir (natural flow, WY75-96) 4435 South Fork American River Near Camino South Fork American River at Chili Bar Reservoir (unregulated flow, WY75-01) 4445 South Fork American River Near Placerville South Fork American River at Chili Bar Reservoir (natural flow, WY75-96) 4445 South Fork American River Near Placerville

5.1 Magnitude of Monthly Water Conditions (IHA Group 1)

Regulated and unregulated monthly flows for the 26-year period are provided by location and with their comparisons summarized in Appendix E. The 12 parameters include monthly median flow values and associated statistics based on the 26-year period of record. Associated CDs and deviation factors were also calculated.

5.2 Magnitude and Duration of Annual Extreme Water Conditions (IHA Group 2)

Regulated and unregulated extreme flow conditions have been computed, and their comparisons are summarized in Appendix E. The 11 parameters based on the 26-year long record measure the magnitude of extreme (minimum and maximum) annual water conditions or various duration periods ranging from one-day to seasonal. The five duration periods for which statistics are calculated include 1-day, 3-day, 7-day (week), 30-day (month), and 90-day (season) for each year. The number of zero-flow days was also computed. The median, CDs and deviation factors

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5.3 Timing of Annual Extreme Water Conditions (IHA Group 3)

Regulated and unregulated extreme flow conditions have been computed, and their comparisons are summarized in Appendix E. The two parameters include the median of the Julian date of the 26 Julian dates when the 1-day minimum water condition occurred in the 26-year record, and the median of the Julian date of the 26 Julian dates when the 1-day maximum water condition occurred. Associated CDs and deviation factors were also calculated.

5.4 Frequency and Duration of High and Low Pulses (IHA Group 4)

The frequency of high and low flow pulses as well as the duration of each for regulated and unregulated conditions is summarized in Appendix E. Four parameters are measured in this group for each of the 26 years in the record. Two parameters measure the number of annual occurrences (frequency) during which the magnitude of the water condition exceeded an upper threshold or remained below a lower threshold, respectively. Two additional parameters measure the number of days (duration) of such high and low pulses. Pulses were defined as those periods within a year in which the daily median water condition rose above the 75th percentile (high pulse) or dropped below the 25th percentile of all daily values for the unregulated hydrology.

5.5 Rate and Frequency of Change in Water Conditions (IHA Group 5)

The rate and frequency of annual hydrograph changes for the unregulated monthly flows are provided in Appendix E. Three parameters were measured in this group for each of the 26 years in the record. Two parameters measured the median of positive and negative differences between consecutive daily values (rate). An additional parameter measured the median number of hydrologic reversals (frequency) based on median daily flows. Associated CDs and deviation factors were also calculated.

6.0 DIURNAL DAILY FLUCTUATION

The purpose of this analysis was to investigate the relationship between mean daily flow and the maximum daily flow during the snowmelt period. This type of analysis provides insight into the diurnal fluctuation of the unregulated snowmelt. The two basins of interest were the South Fork Silver Creek near Ice House (27.3 square miles) and the South Fork American River near Slab Creek Reservoir (493 square miles). Hourly unregulated data are not available for these locations. Instead, data from other drainage basins were utilized in the analysis. Flow data from basins with similar drainage area/elevation characteristics were selected; three small drainage basins and three large drainage basins (Table 6.0-1). Fifteen minute streamflow data were provided by the USGS for the period 1990 through 2001.

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Table 6.0-1. Diurnal Daily Fluctuation Analysis, USGS Sites Gage Location Drainage Area Blackwood Creek near Tahoe City 11.2 Ward Creek at Hwy 89 near Tahoe Pines 1/ 9.7 Trout Creek near Tahoe Valley1/ 36.7 Merced River at Happy Isle 1/ 181 Merced River at Pohono Bridge1/ 321 North Fork American River at North Fork Dam 2/ 342 1/ Minor diversions upstream. 2/ Minor regulation by Lake Clementine, 12,800 acre-feet. However, the impact of regulation on hourly data may be more significant.

The following discussion summarizes the analysis that was performed. The maximum to average day flow ratio (maximum flow ratio) was computed for each day, for the months April through July for each location. Because one plot would be used for all year types, the data was “normalized” so that wet, dry and normal years could be plotted on the same graph. To normalize the data, the volumetric values of flow representing the remaining April-July flow were expressed as a percentage of the total April-July flow. These computed values were plotted against the maximum flow ratio. The results of this analysis are provided in Appendix F.

After reviewing the results, and data, it was discovered that many spikes in the data were the result of single rain events. To dampen out the impact of these events, the maximum flow ratio was averaged over a four day period (the current day and the previous three days) and again plotted against the remaining April-July flow, as a percentage of the total April-July flow. The results of this refined analysis are also provided in Appendix F. This refinement created a relationship with less variability.

This was an investigative analysis. No conclusions will be drawn from the analysis performed.

7.0 FLOOD PEAK FREQUENCY

A flood peak frequency analysis was performed at several sites within the UARP. The sites are described in Table 7.0-1. The methodology applied to analyze these data was developed by the U.S. Army Corps of Engineers, 1962, and described below.

Table 7.0-1. Flood Peak Frequency Analysis Points Rubicon River at Rubicon Spring near Meeks Bay Gerle Creek below Loon Lake Dam South Fork Rubicon River below Gerle Creek near Georgetown South Fork Silver Creek at Ice House Reservoir Silver Creek at Union Valley Reservoir Silver Creek at Camino Diversion Dam South Fork American River near Camino South Fork American River near Placerville

Instantaneous annual maximum events were downloaded from the USGS website. Data were broken down by period, i.e., regulated events versus unregulated events. Hydrologic plotting points were computed as follows:

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1/N 1 – P1 = (0.5)

Where: P1 is the plotting position for the largest event N is the number of years of record

The plotting position for the smallest event is the complement of this value and all the other plotting positions are interpolated linearly between the two (U.S. Army Corps of Engineers, Statistical Methods in Hydrology, 1962). Results of the analysis are summarized in Appendix G (Appendix G, figures 1-1 through 1-8 and figures 2-1 through 2-4).

The purpose of this analysis is to evaluate the 2-year event. Additional analysis is required if recurrence intervals greater than 10 years are of interest.

The available data associated with sites described in Table 7.0-1 span varying hydrological periods. In attempt to capture the potential impact of differing hydrological periods, flood peak frequency curves were prepared for gages outside the American River basin and for the unimpaired daily flow into Ice House Reservoir. These plots can be used to aid the user in evaluating results from this analysis. Results of the analysis are summarized in Appendix G (Appendix G, figures 3-1 through 3-5 and figures 4-1 through 4-16).

8.0 LITERATURE CITED

Richter’s et al. 1999

SMUD 2002. SMUD Upper American River Project, Hydrology Study Plan. Plenary Approval August 5, 2002.

U.S. Army Engineer District Corps of Engineers. Statistical Methods in Hydrology. January 1962.

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Appendix A

A Computation of Simulated Data Inflow to Ice House Reservoir

• Computation of Simulated Data Inflow to Ice House Reservoir - Table 1-1: Streamflow Gages Adjacent to or Nearby the UARP

(Provided in Hardcopy and on CD)

Computation of Simulated Data Inflow to Ice House Reservoir

The inflow to Ice House Reservoir was derived from data provided at the gages listed in Table 1-1.

Table 1-1: Streamflow Gages Adjacent to or Nearby the UARP Gage Drainage USGS USGS Description Elevation Area Coefficient Applied Number (feet) (sq-mi) 10336660 Blackwood Creek near Tahoe City (Blackwood) 6,240 11.2 .72 10336780 Trout Creek near Tahoe Valley (Trout) 6,250 36.7 .241/ 11427700 Duncan Creek near French Meadows (Duncan) 5,270 9.9 1.19 11431800 Pilot Creek above Stumpy Meadows (Pilot) 4,280 11.7 .131/ Constant 0 1/ Applied to flow above estimated base flow.

An adjustment to the flow at Trout and Pilot creeks prior to computing the inflow to Ice House Reservoir was applied. Sample results of the adjustment procedure are plotted in figures 4-1 and 4-2. The inflow to Ice House Reservoir is computed as:

Inflow to Ice House Reservoir = Blackwood times 0.72 plus Trout adjusted flow times 0.24 plus Duncan times 1.19 plus Pilot adjusted flow times 0.13

Where: All flows are in cfs

The daily inflow to Ice House Reservoir are sythensized using the equation above, and then by proportionately adjusting the data each day so that the sum of the synthesized daily volumes for a month equaled the computed monthly volumes of flow based on the USGS computation at Ice House Reservoir.

300 Adjustment to Pilot Gage Data 250 USGS Observed Pilot Data Adjustment to be applied, evaluated annually Adjusted Pilot flow used in computation of Ice House inflow 200

150

100

50 Flow in cfs

0 1/1/75 4/1/75 7/1/75 1/1/76 4/1/76 7/1/76 1/1/77 4/1/77 7/1/77 1/1/78 4/1/78 7/1/78 1/1/79 4/1/79 7/1/79 10/1/74 10/1/75 Time10/1/76 in Days 10/1/77 10/1/78 10/1/79 Figure 4-1

200 Adjustment to Trout Gage Data USGS Observed Trout Data Adjustment to be applied, evaluated annually 150 Adjusted Trout flow used in computation of Ice House inflow

100

50 Flow in cfs

0 1/1/75 4/1/75 7/1/75 1/1/76 4/1/76 7/1/76 1/1/77 4/1/77 7/1/77 1/1/78 4/1/78 7/1/78 1/1/79 4/1/79 7/1/79

10/1/74 10/1/75 Time10/1/76 in Days 10/1/77 10/1/78 10/1/79 Figure 4-2

Appendix B

Monthly Unimpaired Inflow

(Monthly Data Provided in Hardcopy and on CD, Daily Data provided on CD only)

Rubicon River at Rubicon Reservoir Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 163 634 981 1,017 1,054 2,217 2,238 27,773 30,093 8,698 1,388 456 76,711 1976 6,095 3,864 1,345 813 1,229 2,669 5,897 12,504 2,432 395 1,580 349 39,170 1977 306 198 169 182 670 1,109 6,651 6,615 6,317 173 25 39 22,453 1978 16 432 4,380 2,818 1,831 6,402 8,206 25,310 26,982 10,007 1,308 2,102 89,796 1979 123 335 1,036 6,395 1,705 3,891 9,473 28,238 13,567 3,099 183 15 68,061 1980 2,653 3,061 2,123 21,609 5,155 2,558 12,967 22,437 22,308 13,463 1,514 183 110,032 1981 86 465 1,237 1,019 4,412 2,907 12,355 14,955 5,273 259 28 122 43,117 1982 1,799 20,751 20,632 2,669 16,369 4,258 17,937 34,173 28,330 14,277 2,743 5,766 169,705 1983 11,731 3,710 2,945 2,122 2,131 5,460 3,914 27,266 48,124 29,800 9,435 4,523 151,162 1984 2,513 18,816 10,695 3,009 2,128 5,273 7,898 30,063 19,481 6,883 933 512 108,203 1985 1,656 5,386 1,617 1,166 1,535 2,457 14,751 17,013 7,389 612 86 753 54,421 1986 1,289 1,361 3,548 7,888 15,540 16,082 13,844 27,089 23,492 5,999 1,138 905 118,174 1987 1,921 303 221 221 1,697 2,493 14,305 12,538 3,369 370 73 23 37,535 1988 5 534 2,459 1,685 1,793 4,701 7,990 9,840 5,276 355 30 1 34,670 1989 86 2,867 1,675 1,354 2,651 12,065 17,864 20,946 17,613 3,338 264 908 81,632 1990 2,216 2,053 1,395 2,523 1,297 4,796 13,351 11,314 8,437 1,267 27 27 48,704 1991 78 139 157 216 514 5,183 5,941 16,115 15,745 2,436 129 30 46,682 1992 806 2,582 898 707 3,247 3,426 13,372 9,174 2,831 1,135 156 89 38,422 1993 372 980 1,202 2,917 1,448 6,875 10,325 33,856 24,301 10,459 1,813 200 94,747 1994 662 257 438 803 712 3,917 9,784 13,358 4,221 251 14 8 34,423 1995 186 1,893 1,274 4,993 3,437 9,697 8,659 24,650 42,935 32,001 8,424 1,723 139,873 1996 286 50 10,012 3,620 13,752 4,769 12,317 35,987 21,629 7,016 769 227 110,435 1997 217 10,545 12,240 28,683 2,202 6,886 16,683 26,230 16,075 3,246 371 79 123,457 1998 468 1,221 1,162 5,098 2,276 8,301 8,403 14,767 40,615 22,170 3,488 1,335 109,304 1999 434 2,780 2,739 2,528 1,988 2,762 7,252 29,905 29,317 8,941 1,034 271 89,951 2000 542 1,207 804 3,609 3,541 4,589 13,808 26,225 13,275 2,247 270 471 70,589 2001 226 801 809 627 860 5,128 7,597 16,894 1,632 172 38 39 34,823

Maximum 11,731 20,751 20,632 28,683 16,369 16,082 17,937 35,987 48,124 32,001 9,435 5,766 169,705 Minimum 5 50 157 182 514 1,109 2,238 6,615 1,632 172 14 1 22,453 Average 1,368 3,231 3,266 4,085 3,525 5,217 10,510 21,305 17,817 7,003 1,380 784 79,491 Median 434 1,221 1,345 2,523 1,988 4,701 9,784 22,437 16,075 3,246 371 227 76,711 Little Rubicon River at Buck Island Reservoir Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 32 178 440 391 628 929 871 7,940 12,320 1,939 94 90 25,851 1976 1,899 1,093 469 296 361 869 1,738 3,833 188 78 312 69 11,205 1977 60 39 33 36 229 431 2,275 2,346 1,602 47 5 8 7,110 1978 4 99 2,123 1,157 740 1,823 2,487 8,227 8,744 2,326 287 419 28,436 1979 28 77 211 1,439 682 1,173 2,988 9,333 3,782 1,052 42 3 20,811 1980 853 918 583 5,259 1,560 731 3,808 7,492 6,641 2,631 150 37 30,661 1981 20 93 492 539 1,623 925 4,654 5,279 1,198 33 6 24 14,887 1982 843 5,860 5,091 1,079 4,132 1,631 3,637 7,319 4,858 3,650 664 1,692 40,455 1983 2,810 1,289 1,104 644 760 1,838 1,286 6,816 13,238 7,087 1,588 1,143 39,603 1984 853 8,418 3,769 817 636 1,582 2,439 10,211 5,238 1,569 157 118 35,808 1985 532 2,205 531 328 380 702 4,384 5,731 2,035 146 20 149 17,144 1986 254 442 1,364 3,214 4,823 3,204 2,895 7,606 7,771 1,492 174 249 33,487 1987 727 89 53 53 678 660 4,227 2,686 311 82 17 6 9,589 1988 4 116 1,128 641 385 1,429 2,095 2,464 1,052 69 7 0 9,390 1989 19 1,178 503 341 631 3,368 3,658 3,776 2,187 295 57 185 16,198 1990 913 684 452 902 329 884 3,154 1,922 1,014 111 6 6 10,378 1991 16 28 32 44 113 2,034 1,395 4,355 2,865 200 26 6 11,114 1992 318 922 251 173 1,463 1,418 3,972 1,622 480 235 36 20 10,910 1993 116 462 652 1,614 617 2,243 2,871 10,371 5,216 1,353 136 28 25,679 1994 221 52 207 326 375 1,552 3,295 3,936 780 32 3 2 10,781 1995 38 737 498 2,285 960 3,496 3,619 8,256 10,826 7,519 1,614 211 40,059 1996 65 10 3,137 1,190 3,412 1,573 4,277 11,261 4,992 547 128 46 30,638 1997 44 2,828 5,221 7,506 294 2,205 4,779 7,179 2,926 209 69 16 33,277 1998 95 412 353 1,890 651 1,709 2,400 4,483 10,076 4,095 457 207 26,829 1999 88 1,128 833 821 629 581 2,310 9,287 8,906 2,820 206 55 27,664 2000 45 395 309 2,140 1,393 870 4,851 6,666 2,280 250 56 96 19,352 2001 46 163 165 127 234 2,304 3,174 5,556 332 35 8 8 12,150

Maximum 2,810 8,418 5,221 7,506 4,823 3,496 4,851 11,261 13,238 7,519 1,614 1,692 40,455 Minimum 4 10 32 36 113 431 871 1,622 188 32 3 0 7,110 Average 405 1,108 1,111 1,306 1,064 1,562 3,094 6,146 4,513 1,478 234 181 22,202 Median 88 442 498 817 636 1,552 3,154 6,666 2,926 295 69 46 20,811 Gerle Creek at Loon Lake Reservoir Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 54 191 220 561 1,492 2,297 2,037 9,284 2,476 561 117 71 19,361 1976 593 999 551 608 629 1,448 1,758 973 137 63 116 39 7,912 1977 45 42 68 121 289 612 1,086 1,216 289 27 9 13 3,817 1978 11 115 2,086 2,384 1,639 4,164 4,330 5,671 1,797 354 78 87 22,716 1979 53 91 193 1,351 1,257 2,046 4,414 4,715 993 166 41 13 15,335 1980 275 903 803 8,297 3,643 1,923 4,697 4,788 1,351 470 112 34 27,295 1981 25 101 362 585 1,404 1,953 3,782 2,033 315 40 16 20 10,636 1982 107 4,633 6,258 1,644 5,982 3,958 6,181 7,580 2,854 612 154 347 40,311 1983 1,601 2,481 2,390 1,742 2,356 4,462 2,722 9,969 8,696 2,474 458 141 39,492 1984 285 7,145 6,414 1,754 1,987 3,447 3,378 2,420 763 226 62 38 27,920 1985 129 1,633 1,098 551 850 1,643 4,555 2,185 502 72 35 64 13,318 1986 74 259 1,354 3,580 10,417 7,571 4,615 2,924 586 213 61 119 31,773 1987 263 112 139 220 1,301 2,079 2,994 1,209 180 57 27 25 8,606 1988 43 112 712 1,007 930 1,288 1,409 712 368 65 19 17 6,682 1989 18 965 510 406 873 7,218 6,752 4,324 894 133 51 68 22,213 1990 299 495 428 957 799 2,555 3,712 2,071 856 119 24 16 12,331 1991 28 45 59 88 162 2,497 3,682 3,973 1,094 206 36 15 11,885 1992 86 188 181 209 1,401 2,640 2,746 592 150 125 25 21 8,365 1993 101 156 618 2,660 1,779 5,648 6,470 7,190 3,501 452 102 34 28,711 1994 60 59 204 316 747 2,017 2,568 1,781 259 43 10 11 8,074 1995 39 652 1,008 4,893 2,295 7,642 5,948 9,615 5,515 1,582 295 81 39,564 1996 54 43 2,352 2,153 5,720 3,479 5,512 8,974 837 192 69 45 29,429 1997 58 1,317 7,518 9,226 1,358 3,418 3,819 2,112 749 193 56 24 29,848 1998 89 330 478 3,377 2,240 4,329 4,013 6,904 7,151 1,329 148 91 30,479 1999 95 909 1,172 2,608 2,605 2,426 4,180 7,340 2,197 331 99 49 24,010 2000 61 183 271 2,829 3,096 2,720 5,013 3,788 650 145 37 49 18,842 2001 52 173 271 344 581 2,403 3,017 2,178 177 37 14 13 9,259

Maximum 1,601 7,145 7,518 9,226 10,417 7,642 6,752 9,969 8,696 2,474 458 347 40,311 Minimum 11 42 59 88 162 612 1,086 592 137 27 9 11 3,817 Average 170 901 1,397 2,017 2,142 3,255 3,903 4,316 1,679 381 84 57 20,303 Median 61 191 551 1,351 1,404 2,555 3,819 3,788 837 192 56 38 19,361 Gerle Creek at Gerle Creek Reservoir Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 206 542 525 1,107 3,393 5,600 5,387 24,450 8,109 1,450 377 130 51,276 1976 1,519 2,080 1,446 1,419 1,679 3,601 4,658 2,749 440 120 176 101 19,987 1977 119 119 279 566 940 1,293 2,316 3,006 912 112 37 42 9,741 1978 53 280 5,275 6,764 4,070 12,500 12,122 15,226 5,984 1,102 298 206 63,880 1979 161 254 453 3,269 2,592 5,385 12,359 14,433 2,776 489 126 64 42,361 1980 418 1,844 2,108 25,211 10,298 5,184 12,162 11,508 4,028 1,203 272 91 74,328 1981 104 261 696 1,409 3,495 5,198 10,035 4,783 867 113 53 61 27,075 1982 240 12,964 17,909 4,538 15,807 10,825 16,049 16,917 6,104 1,444 436 1,132 104,364 1983 4,401 5,675 6,125 4,614 6,137 12,744 8,431 28,299 22,173 6,095 1,044 300 106,038 1984 538 17,118 17,238 5,411 4,672 9,022 8,234 7,568 2,486 873 188 99 73,448 1985 299 4,078 2,179 1,631 2,325 4,194 13,391 6,132 1,192 163 96 136 35,816 1986 198 995 3,966 10,106 30,465 19,388 10,129 6,930 1,884 741 186 235 85,222 1987 399 249 535 630 3,046 5,324 7,533 2,980 498 166 77 78 21,516 1988 123 300 1,463 3,095 2,537 3,906 4,039 2,012 885 147 67 64 18,636 1989 72 1,924 1,361 1,259 2,690 19,787 16,794 8,125 2,729 417 141 144 55,443 1990 466 744 1,057 2,679 1,974 7,112 8,990 5,108 1,893 329 85 71 30,508 1991 107 169 234 359 575 6,239 9,502 10,348 2,860 548 127 66 31,135 1992 232 457 431 510 3,348 6,673 7,141 1,377 479 199 69 59 20,975 1993 206 333 1,620 6,911 4,553 15,889 16,783 18,635 8,586 1,301 350 108 75,275 1994 171 175 530 799 1,466 5,619 6,388 4,621 684 125 48 54 20,682 1995 104 1,399 2,136 13,889 6,928 20,930 17,508 26,348 14,448 5,240 1,164 244 110,339 1996 177 211 5,516 4,922 17,187 10,545 15,286 19,549 2,407 593 241 113 76,748 1997 138 3,138 20,469 28,183 4,492 8,992 9,523 5,468 2,158 656 176 86 83,480 1998 218 778 1,181 8,691 5,643 12,626 11,829 19,497 19,544 3,374 379 185 83,946 1999 248 2,066 2,985 6,917 7,431 7,647 11,614 18,901 5,984 934 272 110 65,108 2000 206 507 520 7,530 8,809 8,121 13,434 9,761 1,793 475 103 103 51,362 2001 154 485 865 774 1,211 6,512 8,210 5,633 351 106 54 46 24,401

Maximum 4,401 17,118 20,469 28,183 30,465 20,930 17,508 28,299 22,173 6,095 1,164 1,132 110,339 Minimum 53 119 234 359 575 1,293 2,316 1,377 351 106 37 42 9,741 Average 418 2,191 3,671 5,674 5,843 8,921 10,365 11,125 4,528 1,056 246 153 54,189 Median 206 542 1,446 3,269 3,495 7,112 10,035 8,125 2,407 548 176 101 51,362 South Fork Rubicon River at Robbs Peak Diversion Dam Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 226 522 455 814 2,832 4,919 4,990 22,590 8,390 1,324 387 88 47,537 1976 1,380 1,611 1,333 1,208 1,563 3,206 4,320 2,646 451 85 89 93 17,985 1977 109 114 315 664 969 1,015 1,832 2,666 928 126 41 44 8,823 1978 61 244 4,751 6,524 3,621 12,417 11,607 14,232 6,237 1,114 327 177 61,313 1979 162 242 387 2,857 1,988 4,972 11,834 14,475 2,655 480 128 76 40,257 1980 213 1,402 1,944 25,193 9,912 4,856 11,119 10,010 3,987 1,093 240 86 70,055 1981 118 238 498 1,227 3,114 4,833 9,314 4,097 822 110 54 61 24,486 1982 198 12,409 17,354 4,311 14,634 10,229 14,697 13,907 4,840 1,238 420 1,169 95,408 1983 4,170 4,758 5,564 4,277 5,632 12,337 8,503 27,302 20,074 5,393 873 237 99,121 1984 376 14,855 16,123 5,447 4,000 8,304 7,233 7,668 2,566 964 187 91 67,814 1985 253 3,641 1,611 1,609 2,198 3,800 13,161 5,879 1,027 136 90 107 33,512 1986 185 1,097 3,890 9,720 29,861 17,602 8,214 5,967 1,934 786 186 172 79,612 1987 202 204 590 611 2,600 4,833 6,762 2,638 474 162 74 80 19,229 1988 119 280 1,118 3,110 2,393 3,899 3,918 1,936 769 122 71 70 17,805 1989 80 1,428 1,268 1,271 2,706 18,722 14,959 5,660 2,734 422 134 112 49,496 1990 247 372 937 2,565 1,750 6,788 7,861 4,523 1,544 314 91 83 27,075 1991 119 184 261 404 615 5,574 8,669 9,495 2,631 510 135 77 28,673 1992 218 400 374 448 2,901 6,006 6,547 1,169 489 109 65 57 18,782 1993 157 264 1,493 6,331 4,132 15,254 15,361 17,048 7,575 1,264 370 110 69,357 1994 166 173 485 720 1,071 5,366 5,690 4,231 633 122 57 65 18,779 1995 98 1,113 1,680 13,401 6,901 19,792 17,219 24,924 13,306 5,450 1,295 243 105,420 1996 184 250 4,714 4,125 17,081 10,525 14,559 15,750 2,337 597 256 101 70,481 1997 119 2,713 19,291 28,237 4,668 8,302 8,497 4,999 2,098 690 178 93 79,886 1998 192 667 1,047 7,916 5,070 12,357 11,643 18,758 18,459 3,045 345 141 79,639 1999 227 1,723 2,702 6,418 7,188 7,777 11,073 17,220 5,640 899 258 91 61,215 2000 216 484 371 7,001 8,509 8,046 12,543 8,896 1,702 492 99 80 48,439 2001 152 464 885 641 938 6,120 7,736 5,146 258 102 60 51 22,554

Maximum 4,170 14,855 19,291 28,237 29,861 19,792 17,219 27,302 20,074 5,450 1,295 1,169 105,420 Minimum 61 114 261 404 615 1,015 1,832 1,169 258 85 41 44 8,823 Average 369 1,921 3,387 5,446 5,513 8,439 9,624 10,142 4,243 1,006 241 143 50,472 Median 185 484 1,268 3,110 3,114 6,788 8,669 7,668 2,337 510 135 91 48,439 South Fork Silver Creek at Ice House Reservoir Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 148 382 904 1,514 1,687 2,557 3,080 22,237 23,111 3,827 730 293 60,469 1976 1,598 2,972 1,807 1,633 1,419 2,310 4,409 6,822 1,202 230 320 215 24,937 1977 252 287 311 502 767 983 3,482 4,209 2,051 269 62 35 13,209 1978 50 384 3,862 3,703 2,014 6,417 9,054 22,715 17,985 5,014 768 615 72,582 1979 331 342 615 2,461 2,148 3,429 8,176 24,157 7,384 993 304 144 50,484 1980 615 1,169 1,319 18,075 7,127 4,656 11,409 19,020 14,365 6,153 621 215 84,746 1981 240 345 1,023 820 2,557 2,495 9,439 9,852 2,051 275 100 107 29,303 1982 437 9,155 14,605 5,631 15,074 8,009 14,269 28,026 14,807 4,615 995 882 116,505 1983 3,286 4,211 4,221 3,637 4,144 8,058 7,465 24,945 39,882 19,131 5,744 913 125,636 1984 1,009 17,680 12,248 6,531 3,933 6,056 8,292 21,373 9,230 2,051 457 221 89,081 1985 574 3,077 1,938 1,712 1,700 2,530 12,162 11,181 3,188 498 209 338 39,108 1986 394 529 2,111 6,146 15,419 17,448 13,666 19,951 11,165 2,903 811 659 91,202 1987 730 399 439 601 1,840 2,193 9,529 6,877 1,333 349 164 131 24,585 1988 205 410 1,995 1,729 1,933 4,126 6,087 5,026 1,846 314 141 125 23,938 1989 101 1,116 1,122 969 1,593 10,770 17,718 13,986 7,384 937 322 367 56,386 1990 738 820 917 1,752 1,333 3,998 10,433 6,631 4,795 718 199 170 32,506 1991 201 228 257 289 647 3,959 5,066 12,574 7,179 1,231 308 148 32,087 1992 422 632 591 585 2,276 3,444 9,338 4,431 1,414 343 135 96 23,706 1993 312 429 1,429 2,645 2,223 8,249 12,887 28,410 14,432 4,098 909 293 76,316 1994 338 263 820 1,084 1,194 3,075 7,007 7,984 1,436 256 99 103 23,659 1995 168 716 964 9,230 4,939 11,637 12,693 27,052 32,766 17,103 3,156 820 121,245 1996 389 316 4,560 4,059 9,309 7,970 14,303 28,983 10,315 2,597 615 287 83,704 1997 224 3,692 11,827 27,940 5,305 8,548 13,088 15,402 7,428 1,503 431 219 95,606 1998 365 765 1,052 7,033 3,766 8,619 9,598 16,766 33,515 11,598 1,190 502 94,770 1999 394 1,319 2,402 5,197 4,528 4,948 8,619 26,172 16,114 2,917 662 250 73,523 2000 291 476 523 2,994 4,189 5,122 13,080 18,569 5,260 962 250 224 51,940 2001 279 410 566 580 636 4,168 6,247 10,387 878 265 117 110 24,643

Maximum 3,286 17,680 14,605 27,940 15,419 17,448 17,718 28,983 39,882 19,131 5,744 913 125,636 Minimum 50 228 257 289 636 983 3,080 4,209 878 230 62 35 13,209 Average 522 1,945 2,757 4,409 3,841 5,769 9,652 16,435 10,834 3,376 734 314 60,588 Median 338 529 1,122 2,461 2,223 4,656 9,439 16,766 7,384 1,231 322 221 56,386 Silver Creek at Union Valley Reservoir Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 1,156 2,840 2,611 6,347 5,455 13,543 13,156 61,991 45,155 7,397 1,434 579 161,665 1976 3,917 4,394 3,967 3,967 4,217 8,047 12,149 12,888 2,380 543 698 518 57,687 1977 609 884 905 1,869 3,027 3,619 8,527 10,434 4,915 637 206 228 35,860 1978 305 1,396 12,192 16,339 10,584 28,345 28,951 47,123 34,453 7,482 1,672 1,020 189,860 1979 863 1,325 1,826 9,209 6,592 15,550 27,073 57,782 14,491 2,587 678 375 138,352 1980 1,666 6,251 6,819 70,464 28,240 16,328 31,694 41,381 27,964 11,367 1,365 474 244,012 1981 595 1,329 3,174 3,331 8,004 10,493 24,793 19,285 3,035 595 286 325 75,244 1982 1,164 36,005 46,900 16,269 51,938 30,544 53,661 92,428 50,142 9,192 2,286 6,147 396,676 1983 14,440 13,507 18,907 15,881 20,574 43,748 29,737 75,450 118,498 55,465 9,918 1,428 417,554 1984 2,426 73,883 60,247 24,786 14,246 21,510 22,551 43,013 20,383 4,915 1,002 506 289,469 1985 1,470 13,394 5,860 5,168 6,967 11,570 36,445 25,852 5,910 793 496 647 114,572 1986 1,022 4,329 11,193 25,761 99,386 82,675 32,494 37,382 18,038 2,891 992 1,079 317,241 1987 1,587 1,203 1,713 2,859 7,985 11,585 24,171 13,106 2,595 876 403 423 68,507 1988 647 1,547 5,307 7,245 7,702 12,201 13,400 10,375 4,406 716 369 357 64,270 1989 409 4,831 4,601 3,783 6,598 45,274 43,518 31,809 14,591 2,241 734 680 159,068 1990 1,882 2,946 3,325 7,395 5,028 16,175 26,105 17,024 9,145 1,716 470 413 91,623 1991 606 944 1,091 1,412 2,341 17,019 18,806 29,786 14,642 2,823 698 383 90,553 1992 1,200 2,281 2,412 2,856 9,441 14,347 23,034 6,770 2,585 813 357 309 66,406 1993 964 1,587 5,195 15,190 10,838 38,254 41,459 62,132 33,056 6,846 1,924 581 218,027 1994 899 930 3,048 3,069 4,037 13,119 19,003 18,049 3,511 661 282 319 66,926 1995 540 3,769 5,746 30,695 18,080 51,619 47,427 72,717 63,126 28,812 6,581 1,299 330,410 1996 966 1,236 14,032 17,289 43,344 33,221 43,563 65,303 18,149 3,179 1,329 571 242,182 1997 684 15,366 51,486 99,793 17,672 24,457 31,533 28,322 11,773 3,598 946 480 286,110 1998 1,094 2,887 4,032 21,575 17,951 35,666 33,162 51,438 74,423 24,175 1,932 867 269,200 1999 1,265 6,035 8,470 17,845 25,645 21,205 29,863 59,617 33,411 4,890 1,414 535 210,195 2000 1,127 2,645 2,298 16,023 22,025 20,854 35,518 41,799 9,326 2,584 539 486 155,225 2001 817 1,709 3,206 2,556 3,272 14,630 19,611 21,307 1,615 555 304 259 69,842

Maximum 14,440 73,883 60,247 99,793 99,386 82,675 53,661 92,428 118,498 55,465 9,918 6,147 417,554 Minimum 305 884 905 1,412 2,341 3,619 8,527 6,770 1,615 543 206 228 35,860 Average 1,641 7,757 10,762 16,629 17,081 24,281 28,571 39,058 23,767 6,976 1,456 788 178,768 Median 1,022 2,840 4,601 9,209 9,441 17,019 28,951 37,382 14,591 2,823 734 506 159,068 Silver Creek at Junction Reservoir Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 2,163 4,268 5,167 9,877 11,408 24,760 23,274 93,690 71,709 12,940 2,922 1,479 263,658 1976 8,032 8,773 6,905 6,664 6,982 12,441 18,242 20,546 4,194 1,376 1,852 1,378 97,385 1977 1,603 1,851 1,879 3,497 4,535 5,455 12,528 15,621 7,430 1,053 306 336 56,094 1978 489 2,566 20,349 35,949 18,938 48,523 47,980 75,286 55,436 14,228 3,312 3,017 326,071 1979 2,014 2,697 3,468 14,098 11,498 26,021 42,463 88,430 24,729 4,626 1,815 1,068 222,929 1980 3,376 9,258 10,284 136,180 49,443 30,290 49,360 64,645 45,334 19,631 2,865 1,291 421,957 1981 1,448 2,623 5,717 5,993 13,273 20,007 39,102 31,630 6,353 1,661 942 890 129,638 1982 2,626 54,029 70,433 29,132 84,333 55,150 84,961 130,602 68,918 15,772 4,395 8,503 608,854 1983 21,842 21,245 37,914 30,158 40,324 84,764 48,943 111,959 163,302 77,747 17,763 4,067 660,027 1984 5,066 109,121 96,984 40,497 25,313 37,518 36,493 68,304 32,125 8,195 2,212 1,390 463,217 1985 3,070 19,970 10,355 8,739 11,135 18,459 57,045 41,042 10,907 2,085 1,427 2,007 186,240 1986 2,576 6,426 16,931 38,661 160,086 118,063 51,613 60,918 31,872 6,908 2,690 2,544 499,286 1987 3,485 2,574 3,139 4,523 12,929 19,180 36,044 22,136 5,227 1,890 1,186 1,104 113,418 1988 1,861 2,740 8,693 11,112 11,334 18,449 21,183 17,189 7,542 1,675 1,108 1,112 103,999 1989 1,136 7,505 6,913 5,819 10,126 74,597 68,570 49,350 24,331 4,041 1,673 2,036 256,097 1990 3,859 5,086 5,480 11,048 8,012 25,709 40,114 26,406 15,931 3,161 1,322 1,058 147,186 1991 1,484 1,857 2,103 2,488 3,964 26,243 29,914 46,020 23,824 5,043 1,788 1,201 145,930 1992 2,630 3,952 4,050 4,492 16,060 22,498 35,358 13,159 5,311 2,021 1,047 697 111,275 1993 2,020 2,670 8,965 26,867 19,091 67,912 68,021 96,420 52,100 13,297 4,662 2,052 364,077 1994 2,405 2,568 5,540 5,899 7,299 21,553 28,614 28,068 6,141 1,733 1,047 1,062 111,928 1995 1,144 5,940 10,269 60,494 31,763 88,029 81,520 123,327 100,820 48,261 11,778 3,847 567,192 1996 2,535 2,866 22,361 27,956 72,207 59,433 70,930 105,980 32,553 8,169 3,582 2,183 410,755 1997 2,483 22,990 81,991 196,440 35,108 40,899 49,106 46,536 21,802 6,763 2,697 2,083 508,898 1998 2,744 5,231 7,334 41,334 33,299 63,613 57,687 81,520 120,409 39,993 5,590 3,284 462,037 1999 3,134 9,943 14,601 33,682 50,514 42,372 49,926 92,590 52,753 9,813 3,835 2,202 365,365 2000 2,254 4,478 4,239 27,652 38,061 36,885 54,498 64,913 17,220 4,584 1,918 1,678 258,382 2001 2,054 4,001 5,833 4,701 5,896 25,052 32,049 34,400 3,736 1,733 1,199 992 121,645

Maximum 21,842 109,121 96,984 196,440 160,086 118,063 84,961 130,602 163,302 77,747 17,763 8,503 660,027 Minimum 489 1,851 1,879 2,488 3,964 5,455 12,528 13,159 3,736 1,053 306 336 56,094 Average 3,316 12,120 17,700 30,517 29,368 41,255 45,761 61,136 37,482 11,792 3,220 2,021 295,687 Median 2,483 4,478 7,334 14,098 16,060 30,290 47,980 60,918 24,331 5,043 1,918 1,479 258,382 Silver Creek at Camino Diversion Dam Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 2,927 5,001 6,348 11,343 14,510 30,182 27,301 100,543 74,667 14,655 3,742 2,124 293,344 1976 10,273 9,759 7,715 7,437 7,959 13,746 19,206 21,151 4,719 1,978 2,756 2,064 108,763 1977 2,263 2,328 2,353 4,315 5,074 5,989 12,825 16,330 7,828 1,201 347 415 61,268 1978 607 3,117 23,421 47,515 23,548 57,137 53,689 79,230 58,011 15,960 4,256 4,484 370,976 1979 2,745 3,419 4,202 15,864 13,504 30,430 46,592 93,153 27,193 5,672 2,717 1,651 247,141 1980 4,351 10,546 11,819 170,821 59,677 36,117 52,942 67,717 47,914 21,742 3,818 1,929 489,391 1981 1,993 3,289 6,805 7,332 15,244 24,400 41,889 33,435 7,441 2,453 1,544 1,376 147,201 1982 3,538 60,244 76,819 34,390 96,928 65,539 94,708 137,949 72,327 17,737 5,602 10,068 675,850 1983 25,508 23,716 48,489 37,895 51,672 105,397 55,663 120,333 167,529 80,897 20,039 5,899 743,034 1984 6,517 121,423 114,500 47,172 30,500 43,748 39,727 71,140 34,283 9,424 3,027 2,093 523,554 1985 3,984 22,421 12,184 10,090 12,930 21,187 61,875 43,944 12,460 2,877 2,210 3,091 209,255 1986 3,609 7,524 19,525 43,571 193,011 129,293 54,734 63,514 34,164 8,022 3,651 3,400 564,017 1987 4,525 3,255 3,844 5,295 15,186 22,562 37,385 23,695 6,342 2,556 1,857 1,689 128,192 1988 2,760 3,288 9,688 12,667 12,570 19,777 22,154 18,483 8,649 2,320 1,756 1,782 115,896 1989 1,693 8,597 7,764 6,595 11,534 86,212 72,768 51,924 26,355 4,903 2,342 3,085 283,771 1990 4,961 6,010 6,365 12,430 9,213 29,174 42,161 28,398 17,641 3,888 2,030 1,563 163,835 1991 2,087 2,338 2,643 3,061 4,673 29,538 33,371 48,670 25,544 6,032 2,636 1,914 162,506 1992 3,527 4,680 4,799 5,257 19,217 25,445 37,066 14,576 6,437 2,886 1,648 1,006 126,547 1993 2,683 3,129 10,639 33,433 23,474 81,314 75,847 100,678 56,061 15,650 6,642 3,303 412,853 1994 3,445 3,532 6,735 7,169 8,802 24,908 30,105 29,541 7,166 2,548 1,769 1,742 127,462 1995 1,533 6,959 12,814 75,450 38,121 103,537 93,768 140,387 105,053 50,607 13,988 5,681 647,898 1996 3,585 3,787 25,057 32,761 86,425 70,853 78,406 114,448 36,064 10,562 5,356 3,589 470,894 1997 3,885 25,744 95,351 246,398 43,929 45,840 51,674 48,572 24,036 8,425 4,127 3,553 601,534 1998 3,887 6,337 8,943 50,588 41,719 75,712 66,229 91,162 131,119 44,214 8,265 5,317 533,494 1999 4,448 11,756 17,268 41,419 65,304 52,526 56,475 97,514 55,525 11,818 5,741 3,706 423,501 2000 2,998 5,429 5,253 33,931 46,675 43,714 57,875 68,205 19,482 5,621 3,141 2,707 295,032 2001 2,907 5,319 7,307 5,839 7,342 28,967 35,592 36,359 4,803 2,647 2,041 1,652 140,775

Maximum 25,508 121,423 114,500 246,398 193,011 129,293 94,708 140,387 167,529 80,897 20,039 10,068 743,034 Minimum 607 2,328 2,353 3,061 4,673 5,989 12,825 14,576 4,719 1,201 347 415 61,268 Average 4,342 13,813 20,691 37,409 35,509 48,268 50,075 65,224 39,956 13,233 4,335 2,996 335,851 Median 3,527 5,429 8,943 15,864 19,217 36,117 51,674 63,514 26,355 6,032 3,027 2,124 293,344 Brush Creek at Brush Creek Reservoir Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 296 401 597 817 1,430 2,640 1,622 2,143 788 392 361 229 11,716 1976 436 444 473 449 421 279 256 187 102 61 152 57 3,316 1977 65 83 123 205 176 204 142 186 105 32 23 41 1,385 1978 5 163 814 2,697 2,013 3,293 3,443 1,457 506 303 233 287 15,215 1979 200 293 405 1,085 1,138 2,497 1,947 1,741 493 288 235 174 10,497 1980 245 389 529 4,692 10,221 2,579 941 865 400 290 210 237 21,598 1981 228 235 397 794 664 885 607 348 199 117 105 107 4,685 1982 184 971 2,593 2,199 8,881 3,888 8,636 3,128 890 564 361 329 32,623 1983 625 1,376 4,207 2,986 8,689 11,741 6,172 4,530 1,376 783 473 406 43,365 1984 464 3,667 9,603 2,875 2,021 2,002 875 696 463 328 270 234 23,500 1985 363 868 918 683 793 847 934 423 248 144 154 215 6,591 1986 216 346 693 1,236 16,477 4,865 1,340 761 386 367 217 231 27,134 1987 313 306 327 476 721 1,155 383 267 144 81 37 60 4,270 1988 96 198 439 917 266 287 350 258 161 53 44 51 3,118 1989 83 315 401 515 524 3,295 724 323 167 68 82 121 6,617 1990 234 372 165 565 722 997 347 391 250 115 74 69 4,300 1991 78 121 211 187 187 1,958 546 408 271 172 98 73 4,310 1992 144 207 198 332 1,417 787 325 186 101 66 34 30 3,829 1993 76 98 1,068 4,112 2,941 2,422 1,537 517 458 187 99 139 13,654 1994 182 278 415 347 984 492 265 285 182 87 33 47 3,595 1995 138 518 1,266 5,778 1,199 7,809 2,748 3,480 1,409 838 429 339 25,952 1996 383 391 881 3,158 4,160 2,995 1,926 1,829 972 508 324 278 17,806 1997 292 793 7,235 13,019 2,638 1,448 1,071 820 500 288 203 161 28,469 1998 240 372 506 3,998 6,424 2,771 3,855 2,874 1,735 1,072 537 410 24,794 1999 409 593 861 2,742 6,226 3,110 2,273 1,365 852 581 647 353 20,010 2000 376 449 513 1,798 5,252 2,479 1,011 1,189 562 389 283 298 14,601 2001 461 387 479 660 1,260 1,044 893 452 262 176 121 111 6,306

Maximum 625 3,667 9,603 13,019 16,477 11,741 8,636 4,530 1,735 1,072 647 410 43,365 Minimum 5 83 123 187 176 204 142 186 101 32 23 30 1,385 Average 253 542 1,345 2,197 3,253 2,547 1,673 1,152 518 309 216 188 14,195 Median 234 372 513 1,085 1,417 2,422 941 696 400 288 203 174 11,716 South Fork American River at Slab Creek Reservoir Unregulated (proposed Project 184/UARP unregulated flow) Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 10,556 13,510 15,105 22,674 31,271 63,214 58,822 237,608 194,372 42,746 13,901 12,975 716,754 1976 24,240 25,421 22,419 16,393 16,933 27,084 37,390 47,463 11,280 5,942 5,979 5,617 246,160 1977 6,087 6,462 4,510 7,886 8,597 10,223 23,729 30,591 18,898 4,513 1,589 2,415 125,500 1978 2,557 7,514 39,344 88,137 50,305 121,622 127,987 194,019 154,352 42,429 13,670 17,674 859,612 1979 11,524 11,928 11,207 37,500 29,741 69,908 109,271 222,258 72,699 18,801 8,605 7,414 610,855 1980 13,802 22,888 23,297 296,641 155,347 83,869 121,365 181,280 131,480 59,115 15,588 12,625 1,117,296 1981 8,358 10,135 14,170 15,749 30,050 45,899 85,506 81,866 23,055 9,061 3,253 5,994 333,095 1982 10,321 101,871 146,643 73,828 225,517 145,503 238,240 314,540 167,123 54,839 18,662 26,765 1,523,853 1983 58,946 57,599 107,807 83,837 133,466 250,893 138,127 302,363 391,316 183,480 44,746 24,176 1,776,755 1984 27,998 209,519 247,820 108,554 70,066 100,957 91,351 189,046 97,577 27,953 11,677 11,126 1,193,646 1985 14,188 42,799 29,068 21,574 26,273 40,538 129,072 101,207 30,331 10,334 6,132 11,539 463,056 1986 10,140 17,241 36,237 79,027 423,220 256,237 130,421 171,267 103,474 25,186 13,027 14,208 1,279,684 1987 13,062 9,300 7,579 10,332 26,724 41,264 67,034 51,186 13,362 7,418 3,336 5,359 255,956 1988 6,325 8,355 16,896 23,804 21,708 36,035 41,208 40,111 19,388 8,055 3,166 4,478 229,529 1989 4,350 16,322 13,028 12,287 21,438 171,882 154,098 118,315 64,351 15,032 9,280 11,443 611,825 1990 13,512 16,942 12,613 23,122 18,907 55,973 83,558 59,279 36,326 10,955 5,103 7,629 343,919 1991 5,714 6,566 5,186 5,649 8,133 54,528 64,974 99,605 61,899 15,248 6,899 8,329 342,730 1992 8,970 12,979 9,331 10,010 37,812 47,010 69,818 34,060 11,731 8,347 3,227 5,779 259,074 1993 6,920 8,424 23,401 76,436 56,579 168,291 162,266 238,243 141,720 40,660 16,007 13,180 952,127 1994 10,385 10,455 13,219 13,370 16,989 43,033 54,526 58,402 17,638 8,545 3,298 4,777 254,639 1995 5,181 15,033 24,775 155,440 74,960 240,337 196,737 318,273 279,155 157,907 34,408 18,983 1,521,188 1996 16,460 13,637 47,719 64,623 180,935 145,596 166,759 267,135 104,666 30,894 12,896 13,091 1,064,410 1997 11,222 48,169 195,682 500,955 96,137 107,827 128,241 163,423 76,128 20,787 10,603 9,436 1,368,610 1998 10,251 15,216 17,130 93,602 99,404 158,292 147,155 217,468 330,394 137,985 23,976 19,471 1,270,344 1999 15,532 27,991 35,259 78,973 135,836 104,766 125,249 244,139 165,366 36,845 15,791 13,527 999,274 2000 10,846 14,277 11,526 64,955 108,351 95,466 135,989 178,696 63,564 17,457 9,050 9,187 719,363 2001 9,212 12,286 13,631 12,797 17,782 54,053 70,128 97,752 15,380 9,012 3,800 5,655 321,489

Maximum 58,946 209,519 247,820 500,955 423,220 256,237 238,240 318,273 391,316 183,480 44,746 26,765 1,776,755 Minimum 2,557 6,462 4,510 5,649 8,133 10,223 23,729 30,591 11,280 4,513 1,589 2,415 125,500 Average 12,839 28,253 42,393 74,006 78,610 101,493 109,593 157,763 103,594 37,391 11,766 11,217 768,916 Median 10,385 14,277 17,130 37,500 37,812 83,869 121,365 171,267 72,699 18,801 9,280 11,126 716,754 South Fork American River at Slab Creek Reservoir Natural Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 6,993 10,705 14,260 21,918 30,377 63,714 60,341 252,516 210,188 45,622 11,910 6,183 734,729 1976 23,562 23,483 17,629 15,641 16,298 29,068 43,170 60,610 14,503 5,107 7,861 4,548 261,479 1977 4,576 4,516 4,516 8,096 8,736 11,373 29,140 38,140 25,924 3,771 1,056 1,383 141,227 1978 1,480 5,951 39,648 87,741 49,765 121,243 131,181 210,738 166,771 45,254 11,565 13,191 884,529 1979 6,545 8,213 10,455 36,526 28,734 70,382 113,583 239,996 80,913 18,356 7,339 4,834 625,876 1980 10,539 19,772 22,434 299,943 154,141 84,057 132,407 187,867 135,977 62,900 11,785 6,569 1,128,392 1981 5,462 7,361 13,402 15,138 29,593 46,764 96,338 94,913 27,843 6,222 3,338 2,995 349,370 1982 8,229 105,067 149,249 74,732 223,519 144,223 244,528 319,084 172,979 58,358 17,841 23,566 1,541,375 1983 57,064 56,857 105,807 83,065 130,977 245,748 139,093 312,221 398,054 187,037 47,848 21,897 1,785,667 1984 18,584 210,207 243,726 107,989 69,900 100,989 98,601 196,001 103,554 28,403 9,104 6,316 1,193,374 1985 11,483 42,579 24,777 20,630 25,830 42,000 139,668 115,278 36,448 8,000 4,924 7,076 478,694 1986 8,012 15,026 35,947 81,038 416,210 256,719 142,063 177,447 109,771 25,969 8,594 8,440 1,285,236 1987 9,835 7,170 7,446 10,594 26,496 42,240 79,455 64,589 16,302 5,025 2,941 2,834 274,926 1988 4,252 6,306 16,872 23,848 21,992 38,933 50,461 47,924 23,183 4,733 2,765 2,774 244,042 1989 2,858 14,914 13,877 13,330 22,331 175,643 167,060 129,060 71,571 13,463 5,160 7,069 636,335 1990 11,735 13,786 12,603 23,203 19,002 58,247 97,131 69,492 42,558 8,995 3,892 3,249 363,893 1991 3,595 4,499 5,188 5,865 8,314 56,083 70,310 113,743 71,577 15,222 5,570 3,563 363,529 1992 6,847 10,751 9,345 10,214 38,497 48,359 83,701 44,214 13,913 8,548 3,110 1,929 279,426 1993 4,815 6,371 22,943 76,139 54,903 166,648 167,092 254,036 151,259 44,682 13,504 6,379 968,770 1994 6,805 7,117 12,148 12,730 17,074 44,376 63,735 69,175 19,346 5,050 2,920 2,952 263,428 1995 3,616 14,154 25,358 154,299 74,992 239,537 199,685 327,522 295,411 161,477 36,570 12,884 1,545,506 1996 7,689 9,613 47,731 65,633 181,669 144,945 174,693 276,782 110,200 32,861 11,115 7,529 1,070,459 1997 7,640 47,449 196,192 496,062 95,381 108,670 138,744 169,052 80,335 19,656 8,356 5,927 1,373,464 1998 7,385 12,211 16,311 93,084 98,618 158,700 152,272 225,610 344,602 141,523 22,375 14,587 1,287,281 1999 10,408 23,437 33,835 78,295 134,172 104,469 129,264 262,423 173,328 37,465 14,147 8,235 1,009,478 2000 7,159 11,268 10,566 64,354 107,214 95,948 145,760 193,604 68,822 14,169 6,704 5,950 731,516 2001 7,515 9,862 12,907 12,235 17,187 57,281 79,469 113,830 15,075 5,079 3,177 3,441 337,058

Maximum 57,064 210,207 243,726 496,062 416,210 256,719 244,528 327,522 398,054 187,037 47,848 23,566 1,785,667 Minimum 1,480 4,499 4,516 5,865 8,314 11,373 29,140 38,140 13,913 3,771 1,056 1,383 141,227 Average 9,803 26,246 41,673 73,790 77,849 102,087 117,368 169,106 110,385 37,517 10,573 7,270 783,669 Median 7,385 11,268 16,872 36,526 38,497 84,057 129,264 177,447 80,335 18,356 7,861 6,183 731,516 South Fork American River at Chili Bar Reservoir Unregulated (proposed Project 184/UARP unregulated flow) Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 12,427 16,043 18,878 27,830 40,300 79,885 69,062 251,138 199,348 45,219 16,178 14,422 790,730 1976 26,994 28,222 25,403 19,228 19,589 28,845 39,009 48,641 11,923 6,327 6,938 5,980 267,099 1977 6,498 6,989 5,289 9,177 9,710 11,511 24,626 31,763 19,563 4,714 1,732 2,674 134,245 1978 2,592 8,541 44,486 105,166 63,018 142,414 149,728 203,218 157,548 44,345 15,139 19,488 955,683 1979 12,787 13,781 13,763 44,353 36,927 85,677 121,563 233,250 75,809 20,621 10,090 8,514 677,136 1980 15,349 25,342 26,640 326,267 219,882 100,152 127,308 186,739 134,004 60,946 16,916 14,122 1,253,668 1981 9,800 11,619 16,675 20,760 34,240 51,489 89,338 84,063 24,310 9,802 3,914 6,668 362,679 1982 11,486 108,003 163,012 87,709 281,592 170,051 292,770 334,288 172,743 58,400 20,944 28,842 1,729,840 1983 62,895 66,285 134,368 102,691 188,330 325,029 177,101 330,968 400,004 188,422 47,734 26,739 2,050,566 1984 30,926 232,675 308,457 126,707 82,829 113,598 96,875 193,444 100,502 30,027 13,381 12,604 1,342,024 1985 16,483 48,283 34,863 25,884 31,278 45,889 134,969 103,877 31,898 11,246 7,106 12,894 504,672 1986 11,504 19,428 40,613 86,831 527,257 286,952 138,883 176,069 105,910 27,502 14,398 15,665 1,451,013 1987 15,035 11,229 9,643 13,336 31,279 48,559 69,454 52,874 14,272 7,930 3,568 5,740 282,919 1988 6,928 9,604 19,670 29,594 23,385 37,848 43,415 41,739 20,402 8,387 3,443 4,801 249,215 1989 4,872 18,309 15,560 15,541 24,746 192,690 158,670 120,356 65,405 15,458 9,796 12,204 653,605 1990 14,991 19,288 13,652 26,690 23,468 62,266 85,746 61,750 37,903 11,683 5,568 8,062 371,068 1991 6,208 7,327 6,519 6,832 9,313 66,888 68,423 102,183 63,610 16,335 7,517 8,790 369,946 1992 9,877 14,287 10,581 12,109 46,761 51,982 71,872 35,233 12,371 8,766 3,442 5,967 283,248 1993 7,399 9,044 30,144 102,400 75,149 183,582 171,974 241,507 144,611 41,839 16,631 14,061 1,038,342 1994 11,534 12,210 15,838 15,562 23,199 46,138 56,197 60,201 18,788 9,092 3,504 5,074 277,336 1995 6,055 18,305 32,768 191,921 82,530 289,647 214,089 340,247 288,051 163,198 37,118 21,121 1,685,050 1996 18,880 16,108 53,281 84,563 207,201 164,504 178,921 278,685 110,804 34,101 14,940 14,849 1,176,836 1997 13,068 53,178 241,364 583,159 112,793 116,970 135,001 168,603 79,284 22,605 11,888 10,452 1,548,366 1998 11,767 17,562 20,325 118,844 139,963 175,788 171,499 235,613 341,349 144,753 27,369 22,062 1,426,894 1999 18,117 31,732 40,694 96,284 175,145 124,401 139,600 252,757 170,744 40,515 19,875 15,755 1,125,621 2000 13,219 17,112 14,767 76,310 141,515 111,120 142,373 186,203 67,113 19,915 10,838 11,070 811,554 2001 12,120 14,730 16,653 16,967 25,736 60,644 75,768 100,609 17,034 10,125 4,565 6,357 361,307

Maximum 62,895 232,675 308,457 583,159 527,257 325,029 292,770 340,247 400,004 188,422 47,734 28,842 2,050,566 Minimum 2,592 6,989 5,289 6,832 9,313 11,511 24,626 31,763 11,923 4,714 1,732 2,674 134,245 Average 14,438 31,675 50,885 87,878 99,153 117,575 120,157 165,038 106,863 39,344 13,131 12,407 858,543 Median 12,120 17,112 20,325 44,353 46,761 100,152 127,308 176,069 75,809 20,621 10,838 12,204 790,730 South Fork American River at Chili Bar Reservoir Natural Average Monthly Flow - Acre-feet

WY Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Total 1975 8,865 13,239 18,033 27,074 39,405 80,385 70,581 266,046 215,165 48,095 14,186 7,631 808,705 1976 26,316 26,284 20,613 18,476 18,954 30,828 44,789 61,788 15,146 5,492 8,820 4,911 282,418 1977 4,986 5,043 5,295 9,388 9,849 12,661 30,037 39,312 26,589 3,973 1,198 1,642 149,972 1978 1,515 6,978 44,789 104,769 62,479 142,035 152,921 219,937 169,967 47,170 13,034 15,005 980,600 1979 7,809 10,066 13,011 43,380 35,919 86,151 125,875 250,989 84,023 20,177 8,825 5,933 692,157 1980 12,086 22,226 25,777 329,570 218,676 100,341 138,350 193,327 138,501 64,730 13,113 8,067 1,264,764 1981 6,904 8,844 15,908 20,149 33,784 52,354 100,170 97,110 29,098 6,964 4,000 3,669 378,954 1982 9,394 111,198 165,619 88,614 279,595 168,771 299,058 338,832 178,598 61,919 20,123 25,642 1,747,362 1983 61,013 65,543 132,369 101,920 185,841 319,884 178,067 340,826 406,742 191,979 50,836 24,460 2,059,478 1984 21,512 233,363 304,363 126,142 82,663 113,630 104,125 200,398 106,478 30,477 10,809 7,794 1,341,753 1985 13,777 48,063 30,573 24,940 30,836 47,351 145,565 117,948 38,015 8,912 5,898 8,432 520,310 1986 9,376 17,212 40,323 88,843 520,247 287,434 150,525 182,250 112,207 28,285 9,965 9,897 1,456,565 1987 11,808 9,099 9,510 13,598 31,050 49,535 81,875 66,276 17,211 5,538 3,174 3,215 301,889 1988 4,855 7,555 19,646 29,637 23,669 40,746 52,668 49,552 24,196 5,064 3,042 3,097 263,728 1989 3,381 16,901 16,409 16,584 25,639 196,450 171,632 131,100 72,625 13,889 5,676 7,830 678,115 1990 13,214 16,132 13,642 26,771 23,563 64,539 99,319 71,963 44,136 9,723 4,356 3,683 391,042 1991 4,090 5,261 6,521 7,048 9,493 68,443 73,759 116,321 73,288 16,309 6,188 4,024 390,745 1992 7,754 12,060 10,595 12,313 47,445 53,330 85,755 45,387 14,553 8,966 3,325 2,117 303,600 1993 5,294 6,991 29,686 102,103 73,473 181,940 176,800 257,300 154,149 45,862 14,128 7,259 1,054,985 1994 7,954 8,872 14,767 14,921 23,284 47,480 65,406 70,973 20,496 5,597 3,125 3,249 286,125 1995 4,490 17,426 33,351 190,780 82,562 288,847 217,036 349,496 304,308 166,769 39,280 15,022 1,709,367 1996 10,109 12,084 53,292 85,572 207,935 163,854 186,855 288,333 116,338 36,069 13,159 9,287 1,182,886 1997 9,486 52,458 241,874 578,266 112,038 117,813 145,504 174,232 83,491 21,475 9,640 6,944 1,553,220 1998 8,901 14,557 19,506 118,326 139,178 176,197 176,616 243,755 355,557 148,291 25,768 17,179 1,443,831 1999 12,993 27,178 39,270 95,606 173,481 124,103 143,614 271,041 178,706 41,136 18,231 10,463 1,135,824 2000 9,532 14,103 13,807 75,709 140,378 111,602 152,144 201,111 72,371 16,626 8,492 7,832 823,707 2001 10,422 12,306 15,929 16,405 25,141 63,871 85,108 116,687 16,729 6,191 3,942 4,143 376,875

Maximum 61,013 233,363 304,363 578,266 520,247 319,884 299,058 349,496 406,742 191,979 50,836 25,642 2,059,478 Minimum 1,515 5,043 5,295 7,048 9,493 12,661 30,037 39,312 14,553 3,973 1,198 1,642 149,972 Average 11,401 29,668 50,166 87,663 98,392 118,169 127,932 176,381 113,655 39,470 11,938 8,460 873,295 Median 9,376 14,103 19,646 43,380 47,445 100,341 138,350 182,250 83,491 20,177 8,825 7,631 808,705

Appendix C

Computation of Simulated Data Inflow to Junction, Camino and Brush Creek Reservoirs

• Computation of Simulated Data Inflow to Junction, Camino and Brush Creek Reservoirs

(Provided in Hardcopy and on CD)

Computation of Simulated Data Inflow to Junction, Camino and Brush Creek Reservoirs

Brush Creek Daily Flow Equations The Brush Creek unimpaired daily flow computed by using data reported in the USGS water supply records was plotted against the USGS daily flow record at Forest Creek near Wilseyville for the period water year 1986-2001. The daily data were plotted by month and relationships drawn by hand (eye-fitted) and computed.

BrushOct =MIN (4.091*Forest, Forest*11.9-8) BrushNov =4.286*Forest BrushDec =MIN (5.4054*Forest, 5.282*Forest+193.66) BrushJan =MIN (6*Forest, 3.261*Forest+14) BrushFeb =MAX (MIN (4*Forest, 3.111*Forest+18.89), 8.621*Forest-474) BrushMar =MIN (3.125*Forest-12.5, 2.917*Forest) BrushApr =MAX (1.815*Forest+1.21, 4.237*Forest-136) BrushMay =MIN (MAX (3.289*Forest-23.03, 1.875*Forest+3.13), 1.5*Forest+38) BrushJun =MIN (4.211*Forest-4.21, 1.25*Forest+44, 2.225*Forest+4) BrushJul =MAX (3.08*Forest, 5.52*Forest-47) BrushAug =MAX (0, MIN (3.651*Forest+2, 8.4*Forest-5)) BrushSep =MAX (0, MIN (2.857*Forest+5, 4.167*Forest349+1, 9.33*Forest-2.67))

Where: Brush is the estimated daily flow for Brush Creek to Brush Creek Reservoir in cfs Forest is the observed daily flow at Forest Creek near Wilseyville in cfs

Modifications were made to the daily totals based on the relationship between the annual simulated volumes and the volumes at Pilot Creek, Ice House Reservoir and the computed accretions to Chili Bar Reservoir computed by subtracting the SFAR gage at Placerville minus the SFAR gage at Camino. Modifications were made as needed to reduce scatter in the scatter diagrams and straighten out the double mass diagram.

Junction-Camino Daily Flow Equations The Junction-Camino unimpaired daily flow relationships were computed from daily USGS record for the water year period 1951 through 1957. The following data were plotted:

Y-axis: Silver Creek at Placerville = Silver Creek near Placerville minus Excluding flow above South Fork Silver Creek near Ice House minus Union Valley Reservoir Silver Creek at Union Valley and Ice House Reservoir (Adjusted Silver Creek near Placerville)

X-axis: Plot 1) Pilot Creek near Georgetown, and Plot 2) Silver Creek at Union Valley

Relationships were drawn by hand and computed. A relationship using Union Valley is assumed for the months December through June, and for other months using Pilot Creek.

The location of many of the USGS gages used to develop the relationships have been relocated throughout the historical period. The following modification was made to the recoreded data prior to computing the equations:

Pilot Creek Transformation The gage at Pilot Creek near Georgetown (drainage area of 15.1 square miles) has been replaced by the gage at Pilot Creek above Stumpy Meadows (drainage area of 11.7 square miles). The adjustment to the recorded data prior to developing the relationship was:

Plotting PointPilot Creek above Stumpy Meadows = Plotting PointPilot Creek near Georgetown times 11.7/15.1

Union Valley Transformation The gage at Silver Creek at Union Valley (drainage area of 83 square miles) has been replaced the computed inflow to Union Valley (drainage area of 83.9 square miles). The adjustment to the reported data prior to developing the relationship was:

Plotting PointInflow to Union Valley = Plotting PointSilver Creek at Union Valley times 83.9/83

Adjusted Silver Creek near Placerville Transformation The original drainage area for the adjusted Silver Creek near Placerville in 1957 was:

Adjusted Silver Creek near Placerville = Silver Creek near Placerville (177 square miles) - South Fork Silver Creek near Ice House (27.3 square miles) - Silver Creek at Union Valley (83 square miles) = 66.7 square miles

The current drainage area for the accretions to Junction and Camino is:

Accretions to Junction and Camino = Silver Creek below Camino Diversion Dam (171 square miles) Inflow to Ice House (27.5 square miles) - Inflow to Union Valley (83.9 square miles) = 59.6 square miles

The adjustment to the reported data prior to developing the relationship was: Plotting PointJunction-Camino = Plotting PointAdj Silver Creek near Placerville times 59.6/66.7

Relationships Applied

JCOct = MIN (2.37*Pilot, Pilot*0.462+18)

JCNov =MAX (0.104*Pilot+18, 0.395*Pilot+11)

JCDec =4.729*UV76

JCJan =MAX (4.85*UV, 8.517*UV-458)

JCFeb =MIN (5.197*UV, 3.492*UV+126)

JCMar =4.911*UV

JCApr =MIN (4.292*UV, 1.773*UV+231)

JCMay =MIN (3.929*UV+25, 2.557*UV+68)

JCJun =MIN (7.795*UV, 2.154*UV+67)

JCJul =MIN (Pilot*0.325+17, Pilot*0.083+67)

JCAug =MIN (1.327*Pilot+14, Pilot*0.396+23)

JCSep =MIN (4.976*Pilot-13, Pilot*0.479+19)

Where: JC is the combined accretions for Silver Creek at Junction Reservoir and Silver Creek at Camino Reservoir (excluding the flow above Union Valley and Ice House Reservoir and diversions from Brush Creek Reservoir) Pilot is the observed daily flow for the Pilot Creek above Stumpy Meadows UV is the computed unimpaired inflow to Union Valley Reservoir

Exceptions to the above described procedure occurred. Based on water year type and the available USGS record, the application of the monthly relationship may vary. For example, the 1995 spring melt extended into the month of August and the monthly volumes computed using the above procedures appeared too low as compared to the accretions computed from the USGS record. Therefore these equations were not used and the daily flow for these two months was decayed at a rate (0.998 in August and 0.97 in September) to compute monthly volumes comparable to the accretions computed from the USGS record.

Appendix D

Computation of Simulated Data Accretions

• Computation of Simulated Data Accretions

(Provided in Hardcopy and on CD)

Computation of Simulated Data Accretions

Procedures for computing accretions are divided into three categories:

• Unregulated daily accretions: Accretions for these locations are not impacted by upstream diversions or storage. Procedures to compute the unregulated daily accretions are summarized in Table 4-1.

• Regulated daily accretions: Accretions for these locations are impacted by upstream diversions or storage. Accretions are computed for the unregulated portion of the drainage area and must be combined with the upstream regulated data. Procedures to compute the regulated daily accretions are summarized in Table 4-2.

• Regulated monthly accretions: Accretions for these locations are impacted by upstream diversions or storage. Due to insufficient data, accretions are computed for the unregulated portion of the drainage area on a monthly basis. These data must be combined with the upstream regulated data. Procedures to compute the regulated daily accretions are summarized in Table 4-3.

Table 4-1 Unregulated Daily Nodes Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Rubicon 4 Rubicon River at 4.57 51.49 • Rubicon 4 accretion estimate = Inflow to Rubicon Reservoir times Rubicon Springs .1383 • To compute the TOTAL impaired flow at Rubicon 4, add the “Rubicon 4 accretion estimate” to the spill and release from Rubicon Reservoir • To compute the TOTAL unimpaired flow at Rubicon 4, add the “Rubicon 4 accretion estimate” to inflow to Rubicon Reservoir Rubicon 5 Rubicon River below 6.38 51.92 • Rubicon 5 accretion estimate = Inflow to Rubicon Reservoir times Miller Creek .226 • To compute the TOTAL impaired flow at Rubicon 5, add the “Rubicon 4 accretion estimate” plus the “Rubicon 5 accretion estimate” to the spill and release from Rubicon Reservoir • To compute the TOTAL unimpaired flow at Rubicon 5, add the “Rubicon 4 accretion estimate” plus the “Rubicon 5 accretion estimate” to inflow to Rubicon Reservoir Rubicon 6 Rubicon River below 4.03 52.8 • Rubicon 6 accretion estimate = (Inflow to Rubicon Reservoir plus Little Rubicon River Inflow to Buck Island Reservoir) times 1.429 – Inflow to Rubicon Reservoir – Inflow to Buck Island Reservoir - “Rubicon 4 accretion estimate” - “Rubicon 5 accretion estimate” • To compute the TOTAL impaired flow at Rubicon 6, add the “Rubicon 4 accretion estimate” plus the “Rubicon 5 accretion estimate” to the spill and release from Rubicon Reservoir and Buck Island Reservoir • To compute the TOTAL unimpaired flow at Rubicon 6, add the “Rubicon 4 accretion estimate” plus the “Rubicon 5 accretion estimate” to inflow to Rubicon Reservoir and the inflow to Buck Island Reservoir

Table 4-1 (continued) Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Rockbound 1 Rockbound Lake release 4.19 51.52/ • Rockbound 1 accretion estimate = Inflow to Buck Island Reservoir to Buck Island times .72 Reservoir • To compute the TOTAL impaired flow at Rockbound 1, add the “Rockbound 1 accretion estimate” to the diversion from the Rubicon Reservoir • The accretion estimated is the TOTAL unimpaired flow at Rockbound 1 Loon 4 Gerle Creek below 5.17 47.232/ • Loon 4 accretion estimate = Accretions to Gerle Reservoir4/ times .221 Jerrett Creek • To compute the TOTAL impaired flow at Loon 4, add the “Loon 4 accretion estimate” to the spill and release from Loon Lake Reservoir • To compute the TOTAL unimpaired flow at Loon 4, add the “Loon 4 accretion estimate” to the inflow to Loon Lake Reservoir Loon 5 Gerle Creek below Barts 7.22 49.642/ • Loon 5 accretion estimate = Accretions to Gerle Reservoir times .325 and Dellar Creek • To compute the TOTAL impaired flow at Loon 5, add the “Loon 5 accretion estimate” plus the “Loon 4 accretion estimate” to the spill and release from Loon Lake Reservoir • To compute the TOTAL unimpaired flow at Loon 5, add the “Loon 5 accretion estimate” plus the “Loon 4 accretion estimate” to the inflow to Loon Lake Reservoir Loon 6 Gerle Creek Inflow 0.9 48.642/ • Loon 6 accretion estimate = Accretions to Gerle Reservoir times .039 Above Rocky Basin • To compute the TOTAL impaired flow at Loon 6, add the “Loon 6 Creek accretion estimate” plus the “Loon 5 accretion estimate” plus the “Loon 4 accretion estimate” to the spill and release from Loon Lake Reservoir • To compute the TOTAL unimpaired flow at Loon 6, add the “Loon 6 accretion estimate” plus the “Loon 5 accretion estimate” plus the “Loon 4 accretion estimate” to the inflow to Loon Lake Reservoir

Table 4-1 (continued) Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Loon 7 Gerle Creek below 4.79 47.43 • Loon 7 accretion estimate = Accretions to Gerle Reservoir times .206 Rocky Basin Creek • To compute the TOTAL impaired flow at Loon 7, add the “Loon 7 accretion estimate” plus the “Loon 6 accretion estimate” plus the “Loon 5 accretion estimate” plus the “Loon 4 accretion estimate” to the spill and release from Loon Lake Reservoir • To compute the TOTAL unimpaired flow at Loon 7, add the “Loon 7 accretion estimate” plus the “Loon 6 accretion estimate” plus the “Loon 5 accretion estimate” plus the “Loon 4 accretion estimate” to the inflow to Loon Lake Reservoir Loon 8 Gerle Creek Inflow to 2.0 3/ • Loon 8 accretion estimate = Accretions to Gerle Reservoir times .069 Gerle Reservoir • To compute the TOTAL impaired flow at Loon 8, add the “Loon 8 accretion estimate” plus the “Loon 7 accretion estimate” plus the “Loon 6 accretion estimate” plus the “Loon 5 accretion estimate” plus the “Loon 4 accretion estimate” to the spill and release from Loon Lake Reservoir • To compute the TOTAL unimpaired flow at Loon 8, add the “Loon 8 accretion estimate” plus the “Loon 7 accretion estimate” plus the “Loon 6 accretion estimate” plus the “Loon 5 accretion estimate” plus the “Loon 4 accretion estimate” to the inflow to Loon Lake Reservoir Gerle 4 Gerle Creek above 1.01 3/ This drainage area of this sub-basin is lower than the remainder of the basin. Confluence with SF Based on drainage area versus elevation prepared by Vestra, the daily Rubicon River accretions would be used to distribute this daily flow. • Gerle 4 accretion estimate = Gerle 5 accretion estimate times .123 • To compute the TOTAL impaired flow at Gerle 4, the “Gerle 4 accretion estimate” to the spill and release from Gerle Reservoir and Robbs Diversion Dam • To compute the TOTAL unimpaired flow at Gerle 4, add the “Gerle 4 accretion estimate” to the inflow at Gerle Reservoir plus the inflow to Robbs Diversion Dam

Table 4-1 (continued) Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Gerle 5 SF Rubicon above 8.2 3/ This drainage area of this sub-basin is lower than the remainder of the basin. Confluence with Based on drainage area versus elevation prepared by Vestra, the daily Rubicon River accretions would be used to distribute this daily flow. • Gerle 5 accretion estimate = Accretions to Junction Reservoir times .38 • To compute the TOTAL impaired flow at Gerle 5, add the “Gerle 5 accretion estimate” plus the “Gerle 4 accretion estimate” to the spill and release from Gerle Reservoir and Robbs Diversion Dam • To compute the TOTAL unimpaired flow at Gerle 5, add the “Gerle 5 accretion estimate” plus the “Gerle 4 accretion estimate” to the inflow at Gerle Reservoir plus the inflow to Robbs Diversion Dam Gerle Other SF Rubicon below 47.7 3/ • Estimated computed when unimpaired flow to Loon Lake, Gerle Gerle Creek (The Reservoir and Robbs Diversion Dam was computed. location is at the USGS • Accretions estimated by taking total unimpaired flow at location minus gage. The data for this the inflow to Gerle Reservoir minus the inflow to Robbs Diversion Dam. site appear on the CD, • To compute the TOTAL regulated flow at this location, add the file Accretions, page accretion estimate to the release and spill below both Gerle Reservoir Total Flow page. These and Robbs Diversion Dam data are not included on • To compute the TOTAL unregulated flow at this location, add the the accretion estimate to the inflow to Gerle Reservoir and Robbs Diversion UnregDailyAccretions Dam page.) Ice House 4 SF Silver Creek below 3.49 3/ • Ice House 4 accretion estimate = Accretions to Junction Reservoir5/ Peavine Creek times .111 • To compute the TOTAL impaired flow at Ice House 4, add the “Ice House 4 accretion estimate” to the spill and release from Ice House Reservoir • To compute the TOTAL unimpaired flow at Ice House 4, add the “Ice House 4 accretion estimate” to the inflow to Ice House Reservoir

Table 4-1 (continued) Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Ice House 5 SF Silver Creek below 5.8 3/ • Ice House 5 accretion estimate = Accretions to Junction Reservoir Windmiller Ravine times .185 • To compute the TOTAL impaired flow at Ice House 5, add the “Ice House 5 accretion estimate” plus the “Ice House 4 accretion estimate” to the spill and release from Ice House Reservoir • To compute the TOTAL unimpaired flow at Ice House 5, add the “Ice House 5 accretion estimate” plus the “Ice House 4 accretion estimate” to the inflow to Ice House Reservoir Ice House 6 SF Silver Creek below 6.2 3/ • Ice House 6 accretion estimate = Accretions to Junction Reservoir Big Hill Canyon times .197 • To compute the TOTAL impaired flow at Ice House 6, add the “Ice House 6 accretion estimate” plus the “Ice House 5 accretion estimate” plus the “Ice House 4 accretion estimate” to the spill and release from Ice House Reservoir • To compute the TOTAL unimpaired flow at Ice House 6, add the “Ice House 6 accretion estimate” plus the “Ice House 5 accretion estimate” plus the “Ice House 4 accretion estimate” to the inflow to Ice House Reservoir Ice House 7 SF Silver Creek at 2.2 3/ • Ice House 7 accretion estimate = Accretions to Junction Reservoir Junction Reservoir times .07 • To compute the TOTAL impaired flow at Ice House 7, add the “Ice House 7 accretion estimate” plus the “Ice House 6 accretion estimate” plus the “Ice House 5 accretion estimate” plus the “Ice House 4 accretion estimate” to the spill and release from Ice House Reservoir • To compute the TOTAL unimpaired flow at Ice House 7, add the “Ice House 7 accretion estimate” plus the “Ice House 6 accretion estimate” plus the “Ice House 5 accretion estimate” plus the “Ice House 4 accretion estimate” to the inflow to Ice House Reservoir

Table 4-1 (continued) Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Junction 4 Silver Creek below 3.6 3/ • Junction 4 accretion estimate = Accretions to Camino Reservoir6/ Grey Horse Creek times .147 • To compute the TOTAL impaired flow at Junction 4, add the “Junction 4 accretion estimate” to the spill and release from Junction Reservoir • To compute the TOTAL unimpaired flow at Junction 4, add the “Junction 4 accretion estimate” to the inflow to Junction Reservoir Junction 5 Silver Creek below 14 3/ • Junction 5 accretion estimate = Accretions to Camino Reservoir times Onion Creek .571 • To compute the TOTAL impaired flow at Junction 5, add the “Junction 5 accretion estimate” plus the “Junction 4 accretion estimate” to the spill and release from Junction Reservoir • To compute the TOTAL unimpaired flow at Junction 5, add the “Junction 5 accretion estimate” plus the “Junction 4 accretion estimate” to the inflow to Junction Reservoir Junction 6 Silver Creek below 3.2 3/ • Junction 6 accretion estimate = Accretions to Camino Reservoir times Sugar Pine Creek .131 • To compute the TOTAL impaired flow at Junction 6, add the “Junction 6 accretion estimate” plus the “Junction 5 accretion estimate” plus the “Junction 4 accretion estimate” to the spill and release from Junction Reservoir • To compute the TOTAL unimpaired flow at Junction 6, add the “Junction 6 accretion estimate” plus the “Junction 5 accretion estimate” plus the “Junction 4 accretion estimate” to the inflow to Junction Reservoir

Table 4-1 (continued) Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Junction 7 Silver Creek at Camino 0.4 3/ • Junction 7 accretion estimate = Accretions to Camino Reservoir times Reservoir .016 • To compute the TOTAL impaired flow at Junction 7, add the “Junction 7 accretion estimate” plus the “Junction 6 accretion estimate” plus the “Junction 5 accretion estimate” plus the “Junction 4 accretion estimate” to the spill and release from Junction Reservoir • To compute the TOTAL unimpaired flow at Junction 7, add the “Junction 7 accretion estimate” plus the “Junction 6 accretion estimate” plus the “Junction 5 accretion estimate” plus the “Junction 4 accretion estimate” to the inflow to Junction Reservoir Camino 3 Silver Creek below 3.1 3/ • Camino 3 accretion estimate = (Accretions to Slab Creek Reservoir Round Tent Canyon minus Brush Cree Reservoir Inflow)7/ times .086 • To compute the TOTAL impaired flow at Camino 3, add the “Camino 3 accretion estimate” to the spill and release from Camino Reservoir • To compute the TOTAL unimpaired flow at Camino 3, add the “Camino 3 accretion estimate” to the inflow to Junction Reservoir Camino 4 Silver Creek Halfway, 3.8 3/ • Camino 4 accretion estimate = (Accretions to Slab Creek Reservoir no name creek minus Brush Cree Reservoir Inflow) times .106 • To compute the TOTAL impaired flow at Camino 4, add the “Camino 4 accretion estimate” plus the “Camino 3 accretion estimate” to the spill and release from Camino Reservoir • To compute the TOTAL unimpaired flow at Camino 4, add the “Camino 4 accretion estimate” plus the “Camino 3 accretion estimate” to the inflow to Camino Reservoir

Table 4-1 (continued) Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Camino 5 Mouth of Silver Creek 2.2 3/ • Camino 5 accretion estimate = (Accretions to Slab Creek Reservoir minus Brush Cree Reservoir Inflow) times .061 • To compute the TOTAL impaired flow at Camino 5, add the “Camino 5 accretion estimate” plus the “Camino 4 accretion estimate” plus the “Camino 3 accretion estimate” to the spill and release from Camino Reservoir • To compute the TOTAL unimpaired flow at Camino 5, add the “Camino 5 accretion estimate” plus the “Camino 4 accretion estimate” plus the “Camino 3 accretion estimate” to the inflow to Camino Reservoir Brush 4 Brush Creek Inflow to 3.3 3/ • Brush Creek 4 accretion estimate = Inflow to Brush Creek Reservoir Slab Creek Reservoir times .429 • To compute the TOTAL impaired flow at Brush Creek 4, add the “Brush Creek 4 accretion estimate” to the spill and release from Brush Creek Reservoir • To compute the TOTAL unimpaired flow at Brush Creek 4, add the “Brush Creek 4 accretion estimate” to inflow to Brush Creek Reservoir Slab 4 SF American River 8.01 3/ • Slab Creek 4 accretion estimate = (Accretions to Chili Bar Reservoir 8/ below Iowa Canyon minus the unregulated flow at the Rock Creek gage) times .255 Creek • To compute the TOTAL impaired flow at Slab Creek 4, add the “Slab Creek 4 accretion estimate” to the spill and release from Slab Creek Reservoir • To compute the TOTAL unimpaired flow at Slab Creek 4, add the “Slab Creek 4 accretion estimate” to the inflow to Slab Creek Reservoir

Table 4-1 (continued) Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles 1/ (inches) Slab 5 SF American River 9.5 3/ • Slab Creek 5 accretion estimate = (Accretions to Chili Bar Reservoir above Mosquito Road minus the unregulated flow at the Rock Creek gage) times .303 Bridge • To compute the TOTAL impaired flow at Slab Creek 5, add the “Slab Creek 5 accretion estimate” plus the “Slab Creek 4 accretion estimate” to the spill and release from Slab Creek Reservoir • To compute the TOTAL unimpaired flow at Slab Creek 5, add the “Slab Creek 5 accretion estimate” plus the “Slab Creek 4 accretion estimate” to the inflow to Slab Creek Reservoir Slab 6 SF American River 80.3 3/ • Slab Creek 6 accretion estimate = (Accretions to Chili Bar Reservoir below Rock Creek minus the unregulated flow at the Rock Creek gage) times .232 plus unregulated flow at the Rock Creek Gage • To compute the TOTAL impaired flow at Slab Creek 6, add the “Slab Creek 6 accretion estimate” plus the “Slab Creek 5 accretion estimate” plus the “Slab Creek 4 accretion estimate” to the spill and release from Slab Creek Reservoir • To compute the TOTAL unimpaired flow at Slab Creek 6, add the “Slab Creek 6 accretion estimate” plus the “Slab Creek 5 accretion estimate” plus the “Slab Creek 4 accretion estimate” to the inflow to Slab Creek Reservoir Slab 7 SF American River 6.53 3/ • Slab Creek 7 accretion estimate = (Accretions to Chili Bar Reservoir Above Chili Bar minus the unregulated flow at the Rock Creek gage) times .2082 Reservoir • To compute the TOTAL impaired flow at Slab Creek 7, add the “Slab Creek 7 accretion estimate” plus the “Slab Creek 6 accretion estimate” plus the “Slab Creek 5 accretion estimate” plus the “Slab Creek 4 accretion estimate” to the spill and release from Slab Creek Reservoir • To compute the TOTAL unimpaired flow at Slab Creek 7, add the “Slab Creek 7 accretion estimate” plus the “Slab Creek 6 accretion estimate” plus the “Slab Creek 5 accretion estimate” plus the “Slab Creek 4 accretion estimate” to the inflow to Slab Creek Reservoir 1/ Drainage area for accretions only (excludes area upstream or reservoirs) and upstream accretion flow point. 2/ Precipitation for accretions area only

3/ Precipitation not used in adjustment 4/ Accretions to Gerle Reservoir are computed by taking the total unregulated flow at Gerle Reservoir minus the unregulated flow into Loon Lake Reservoir 5/ Accretions to Junction Reservoir are computed by taking the total unregulated flow at Junction Reservoir minus the unregulated flow into Union Valley and Ice House reservoirs 6/ Accretions to Camino Reservoir are computed by taking the total unregulated flow at Camino Reservoir minus the unregulated flow into Junction Reservoir 7/ Accretions to Slab Creek Reservoir is the estimated inflow due to the drainage area below El Dorado Powerhouse. This is the estimate that will be added to the Hydrologics estimate when computing inflow to Slab Creek Reservoir (excluding flow into Brush Creek Reservoir) 8/ Accretions to Chili Bar Reservoir are computed by taking the total unregulated flow at Chili Bar Reservoir minus the unregulated flow into Slab Creek Reservoir

Table 4-2 Unregulated Daily Nodes Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Annual Square Precipitation Miles (inches) 1 Rubicon River inflow to 23.1 No pcp adjustment Estimated at 87.2% of the unregulated inflow to Rubicon Reservoir Rubicon Reservoir (excluding reservoir) 2 Highland Creek inflow to 4.19 No pcp adjustment Estimated at 72% of the unregulated inflow to Buck Island Reservoir Rockbound Reservoir 3 Ellis Creek Inflow to Loon 1.4 No pcp adjustment Estimated at 17.5% of the unregulated inflow to Loon Lake Reservoir Lake 4 SF Rubicon Inflow to Robbs 15.2 No pcp adjustment Estimated at 100% of the unregulated inflow to Robbs Peak Reservoir Peak Reservoir 5 SF Silver Creek Inflow to Ice 21.3 No pcp adjustment Estimated at 72% of the unregulated inflow to Ice House Reservoir House Reservoir 6 Tells Creek Inflow to Union 9.22 47.72 Estimated at 10.6% of the unregulated inflow to Union Valley Reservoir Valley Reservoir 7 Big Silver Creek Inflow to 31.52 49.83 Estimated at 37.8% of the unregulated inflow to Union Valley Reservoir Union Valley Reservoir 8 Jones Fork Silver Creek Inflow 25.37 49.54 Estimated at 30.3% of the unregulated inflow to Union Valley Reservoir to Union Valley Reservoir 9 Little Silver Creek Inflow to 12.33 No pcp adjustment Estimated at 27.4% of the unregulated inflow to Junction Reservoir Junction Reservoir 10 Slab Creek Inflow to Slab 12.32 No pcp adjustment Estimated at 34.2% of the accretions to Slab Creek Reservoir Creek (accretions to Slab Creek Reservoir is the estimated inflow due to the drainage area below El Dorado Powerhouse and excluding inflow to Brush Creek) 11 Iowa Canyon above SF 7.98 No pcp adjustment Estimated at 25.4% of the accretions to Chili Bar Reservoir excluding American River the computed unregulated flow at the Rock Creek gage 12 Rock Creek above SF 74.61 No pcp adjustment Estimated at 5.1% of the accretions to Chili Bar Reservoir excluding the American River computed unregulated flow at the Rock Creek gage plus the computed unregulated flow at the Rock Creek

Table 4-3 Regulated Monthly Nodes Node Description Drainage Estimated Coefficients to Compute Accretions Identification Area Average Square Annual Miles 1/ Precipitation (inches) Chili Bar 4 SF American River below 32.7 No pcp Estimated at 44.8% of the unregulated inflow at the Rock Creek gage Dutch Creek adjustment Chili Bar 5 SF American River below 128.4 No pcp Estimated at 175.9% of the unregulated inflow at the Rock Creek gage. Greenwood adjustment Chili Bar 6 SF American River below 100.2 No pcp Estimated at 137.3% of the unregulated inflow at the Rock Creek gage Weber Creek adjustment 1/ Drainage area for accretions only (excludes area upstream or reservoirs) and upstream accretion flow point. With the exception of Weber Creek Reservoir only.

Appendix E

IHA Analysis

(Provided on CD only)

Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow)

Errors

No Errors

01/05/2004 Page 1 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow)

IHA Annual Summary Statistics

Year October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min 1-day max 1875 0.88 3.21 3.57 9.13 26.86 37.36 34.24 150.99 41.61 9.12 1.91 1.19 0.38 0.42 0.44 0.84 2.46 230.43 1876 9.64 16.78 8.96 9.88 10.94 23.55 29.55 15.82 2.31 1.02 1.89 0.65 0.28 0.29 0.29 0.64 0.69 107.8 1877 0.74 0.71 1.1 1.96 5.21 9.95 18.25 19.78 4.85 0.45 0.15 0.21 0.09 0.1 0.11 0.14 0.18 44.95 1878 0.19 1.94 33.92 38.77 29.51 67.71 72.76 92.23 30.2 5.76 1.26 1.47 0.12 0.12 0.17 0.19 1.17 220.08 1879 0.89 3.21 3.57 9.13 26.86 37.36 34.24 150.99 41.61 9.12 1.91 1.19 0.38 0.42 0.34 0.59 1.67 230.43 1880 4.47 15.17 13.06 134.94 63.34 31.28 78.94 77.87 22.7 7.64 1.81 0.56 0.25 0.25 0.25 0.33 0.78 1302.16 1881 0.41 1.7 5.89 9.52 25.28 31.76 63.55 33.06 5.29 0.64 0.26 0.34 0.17 0.19 0.25 0.26 0.34 96.34 1882 1.74 77.85 101.77 26.73 107.72 64.37 103.88 123.28 47.97 9.96 2.51 5.83 0.28 0.3 0.47 1.59 3.78 811.55 1883 26.04 41.69 38.86 28.34 42.42 72.56 45.75 162.13 146.13 40.23 7.45 2.37 1.4 1.4 1.47 2.32 4.08 358.22 1884 4.64 120.08 104.31 28.53 34.54 56.06 56.78 39.35 12.82 3.68 1.01 0.64 0.54 0.54 0.56 0.64 1.1 624.11 1885 2.1 27.45 17.85 8.96 15.3 26.73 76.55 35.54 8.44 1.16 0.57 1.08 0.41 0.41 0.44 0.54 0.83 119.67 1886 1.2 4.34 22.03 58.23 187.57 123.12 77.55 47.56 9.84 3.47 0.99 2.01 0.54 0.54 0.56 0.62 2.07 1321.06 1887 4.28 1.88 2.26 3.58 23.42 33.82 50.31 19.67 3.02 0.93 0.44 0.42 0.38 0.37 0.37 0.4 0.47 144.79 1888 0.7 1.88 11.58 16.37 16.17 20.95 23.67 11.58 6.19 1.06 0.32 0.29 0.25 0.25 0.21 0.27 0.3 112.05 1889 0.3 16.22 8.29 6.6 15.73 117.39 113.46 70.33 15.02 2.17 0.83 1.15 0.15 0.17 0.19 0.3 1.01 380.76 1890 4.87 8.31 6.96 15.56 14.39 41.55 62.39 33.68 14.38 1.93 0.39 0.27 0.17 0.18 0.18 0.2 0.36 156.01 1891 0.45 0.76 0.96 1.42 2.92 40.61 61.87 64.62 18.39 3.35 0.59 0.25 0.17 0.17 0.17 0.22 0.45 445.83 1892 1.4 3.16 2.94 3.4 24.35 42.94 46.15 9.64 2.53 2.04 0.41 0.35 0.17 0.17 0.17 0.35 0.42 86.57 1893 1.64 2.62 10.05 43.27 32.03 91.85 108.74 116.93 58.84 7.36 1.65 0.57 0.25 0.31 0.37 0.53 0.83 249.68 1894 0.97 0.99 3.33 5.13 13.46 32.8 43.16 28.96 4.36 0.7 0.16 0.18 0.1 0.13 0.14 0.15 0.25 64.2 1895 0.63 10.96 16.39 79.57 41.33 124.29 99.96 156.36 92.68 25.72 4.8 1.35 0.18 0.2 0.31 0.64 0.97 571.74 1896 0.87 0.73 38.25 35.01 99.44 56.58 92.63 145.95 14.07 3.12 1.12 0.75 0.5 0.5 0.52 0.61 0.89 735.93 1897 0.94 22.13 122.27 150.04 24.46 55.6 64.17 34.35 12.59 3.14 0.91 0.4 0.2 0.26 0.33 0.4 0.91 1429.9 1898 1.45 5.55 7.78 54.92 40.33 70.41 67.44 112.28 120.18 21.62 2.4 1.52 0.27 0.45 0.47 1.39 1.78 453.48 1899 1.55 15.27 19.05 42.42 46.91 39.45 70.24 119.37 36.92 5.38 1.61 0.82 0.31 0.36 0.31 0.41 1.02 241.81 1900 0.99 3.07 4.4 46.02 53.29 44.23 84.25 61.61 10.93 2.36 0.59 0.83 0.18 0.23 0.25 0.36 0.65 353.18 1901 0.84 2.91 4.41 5.6 10.47 39.07 50.7 35.42 2.98 0.6 0.22 0.21 0.14 0.17 0.19 0.21 0.33 119.35 1975 8.67 8.35 8.53 8.5 8.05 7.83 6.86 8.7 10.29 9.7 8.84 8.2 5.3 5.37 5.53 6.27 7.28 12 1976 8.93 7.81 8.48 8.15 8.25 8.32 8.63 8.16 8.41 8.55 8.03 7.79 6.4 6.53 7.06 7.72 7.98 11 1977 8.18 7.97 8.27 9.13 9.23 4.67 4.27 4.64 4.13 4.3 4.09 3.99 3.6 3.63 3.73 3.88 3.93 9.8 1978 3.93 4 4.45 4.61 5.12 8.03 8.4 8.72 8.17 7.71 7.89 8.27 3.6 3.8 3.8 3.92 4.11 10 1979 8.62 8.35 8.53 8.5 8.05 7.83 6.86 8.7 10.29 9.7 8.84 8.2 5.3 5.37 5.53 6.27 7.28 12 1980 8.62 8.34 8.24 9.85 8.74 7.95 8.61 8.76 8.14 8.3 8.15 8.08 7.2 7.3 7.41 7.66 7.87 25 1981 7.95 7.9 7.77 8.03 8.09 8.04 8.46 8.21 8.14 8.08 8.06 7.96 7.5 7.5 7.54 7.73 7.87 9.5 1982 8.19 9.67 9.21 7.96 9.61 9.48 10.22 15.95 8.3 8.32 8.15 8.3 7.7 7.7 7.7 7.82 8.19 103 1983 8.71 8.65 7.96 7.77 7.88 7.91 7.54 11.45 11.95 9.33 8.57 8.38 5.8 5.8 5.93 6.8 7.65 17 1984 8.22 9.86 23.91 8.37 8.2 9.34 8.5 8.81 8.21 8.01 8.1 8.48 7.7 7.8 7.91 7.99 8.06 238 1985 8.69 9.09 8.26 8.55 8.64 8.78 10.12 8.73 8.29 8.13 8.27 8.13 7.8 7.87 7.94 8.08 8.17 11 1986 8.26 8.41 8.95 9.7 11.32 10.64 9.23 8.84 8.92 8.73 8.56 8.52 8 8 8 8.23 8.51 31 1987 8.51 8.61 8.5 8.61 8.9 9.05 9.33 8.61 8.29 8.77 8.73 8.42 8 8 8 8.16 8.36 14 1988 8.34 8.33 9.55 9.3 9.39 9.04 9.04 8.81 9.12 8.55 8.76 8.8 8 8.03 8.1 8.24 8.71 12 1989 8.86 9.93 8.55 8.33 9.06 11.61 10.24 9.08 8.73 8.93 8.7 8.82 7.7 7.7 7.87 8.24 8.6 16 1990 9.12 8.81 8.92 9.84 9.53 9.17 9.6 9.6 9.17 8.98 9.01 8.84 8.3 8.3 8.4 8.74 8.94 13 1991 12.27 8.74 8.55 8.55 8.53 9.6 9.6 9.8 8.94 8.97 8.76 8.42 8.3 8.3 8.17 8.28 8.54 25 1992 9 8.89 8.61 8.59 9.18 8.83 9.24 10.03 9.81 9.4 9.04 8.94 8 8 8.11 8.51 8.63 14 1993 13.31 8.72 9.03 9.61 8.97 9.95 9.46 9.67 9.71 9.05 8.71 8.45 8 8 8.1 8.33 8.61 54 1994 8.91 8.7 8.9 8.62 9.6 9.75 9.54 9.42 9.67 9.31 9.47 9.71 8.3 8.3 8.39 8.61 8.74 10 1995 9.54 9.97 9.94 11.08 9.37 10.84 9.67 10.73 9.39 15.69 9.14 9.18 8 8.13 8.23 9.04 9.2 50 1996 9.32 9.65 11 11.23 12.79 11.65 10.76 48.71 9.12 9.27 8.77 8.9 8 8.17 8.51 8.76 8.92 403 1997 11.2 9.43 11.3 13.03 10.25 9.26 9.8 9.34 9.9 9.35 9.62 9.84 8.5 8.57 8.59 9.13 9.45 42 1998 10.01 9.93 10.21 10.45 10.06 11.09 11.2 12.03 13.33 11.9 11.81 12.03 9.4 9.53 9.56 9.77 10 18 1999 12 11.2 11.45 12 11.75 11.65 12.5 14.9 13.57 12.03 12 11.97 11 11 11 11.2 11.54 16 2000 11.87 11.83 11.52 12.26 11.82 11.26 13.6 12.77 11.1 10.87 9.54 9.46 8.6 8.6 8.6 8.65 8.87 17 2001 8.69 8.92 9.13 10.75 9.43 11.37 11.8 9.02 8.72 9.38 9.96 10.57 8.3 8.3 8.39 8.7 8.9 16

01/05/2004 Page 2 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow)

IHA Annual Summary Statistics (Cont)

Year 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

1875 221.96 205.18 152.78 79.64 0 0.02 280 135 4 18 12 6.25 8.67 -6.17 127 1876 51.11 46.82 31.58 24.24 0 0.03 248 300 6 14 6 2.5 4.14 -2.03 124 1877 40.41 34.47 20.01 16.31 0 0.02 228 135 3 60 3 1.67 1.8 -1.26 107 1878 148.03 112.91 102.4 78.5 0 0.01 276 364 4 11 9 14.67 9.9 -5.3 115 1879 221.96 205.18 152.78 79.64 0 0.01 280 135 4 11.25 12 6.25 8.73 -6.14 128 1880 861.64 471.68 141.25 78.29 0 0.01 275 13 3 14.33 11 9.45 20.87 -9.55 94 1881 90.99 84.37 68.37 58.9 0 0.02 210 121 3 31 6 9.5 4.37 -2.35 114 1882 605.34 316.52 141.06 108.95 0 0.01 280 355 5 3.8 7 22.43 32.89 -11.19 96 1883 277.6 239.54 211.36 122.76 0 0.03 264 73 1 3 12 14.67 15.54 -8.01 109 1884 375.63 275.41 125.95 86.03 0 0.01 260 322 1 58 9 16.89 18.35 -9.83 124 1885 115.24 111.37 78.56 47.15 0 0.02 240 101 4 21.25 7 8.29 4.01 -2.57 118 1886 966.93 560.8 243.14 132.74 0 0.01 251 49 4 12.25 6 19.67 24.44 -11.87 107 1887 104.15 71.55 50.55 38.33 0 0.03 274 44 4 29 4 11 3.18 -1.71 112 1888 48.58 36.19 24.29 20.67 0 0.02 251 5 4 25.75 5 1.8 2.99 -2.09 106 1889 299.81 236.55 135.26 102.01 0 0.01 279 68 4 15 4 22.25 9.49 -4.97 114 1890 117.74 84.27 63.83 46.54 0 0.01 255 114 2 33.5 9 6.78 5.57 -3.34 127 1891 213.41 111.67 68.15 56.68 0 0.01 263 64 4 19.5 3 23.33 5.37 -3.94 117 1892 84.4 77.19 56.68 39.12 0 0.01 275 93 3 23.67 4 13.25 2.39 -1.55 109 1893 208.21 164.42 135.18 113.22 0 0.01 271 78 4 12.75 7 19.43 9.19 -5.86 98 1894 62.93 58.6 45.67 35.76 0 0.01 228 108 4 33.75 7 7 2.08 -1.27 134 1895 453.61 332.37 175.04 132.64 0 0.01 275 122 4 12.25 10 16.9 23.37 -14.27 120 1896 685.15 400.5 164.99 100.14 0 0.01 328 138 4 14.5 9 14 26.5 -11.17 102 1897 1094.54 616.48 221.61 105.08 0 0.01 273 1 4 18.75 13 10.23 22.68 -14.06 122 1898 313.47 196.22 133.51 109.43 0 0.01 275 84 4 9.25 12 11 12.46 -8.75 123 1899 181.96 150.76 120.66 79.56 0 0.01 272 18 2 32.5 11 10.09 9.18 -5.37 112 1900 184.16 132.96 88.56 68.41 0 0.01 238 45 4 16 8 13.5 10.14 -6.66 133 1901 94.66 84.17 60.03 42.42 0 0.01 221 85 2 46.5 3 17 2.75 -1.89 105 1975 12 11.29 10.67 9.94 0 0.65 126 347 00000.48 -0.44 56 1976 9.93 9.46 9 8.42 0 0.85 307 300 00000.26 -0.28 44 1977 9.4 9.3 9.23 8.9 0 0.62 271 52 00000.19 -0.28 54 1978 9.73 9.51 8.87 8.61 0 0.57 308 135 00000.31 -0.27 84 1979 12 11.29 10.67 9.94 0 0.65 126 347 00000.5-0.44 56 1980 19 13.99 10.04 8.99 0 0.87 99 13 00000.71 -0.52 61 1981 9.1 8.93 8.51 9.02 0 0.94 334 139 00000.25 -0.2 58 1982 71.67 37.71 16.18 11.96 0 0.81 277 149 00132.13 -1.49 84 1983 14.33 13.86 13.23 14.1 0 0.67 100 73 00000.64 -0.37 67 1984 158 74.91 24.43 14.24 0 0.8 218 362 00123.63 -2.65 78 1985 11 10.86 10.19 9.26 0 0.92 360 316 00000.37 -0.27 61 1986 24.67 17.43 12.53 10.56 0 0.87 285 48 00001.09 -0.81 77 1987 10.67 9.89 9.34 9.1 0 0.92 278 44 00000.5-0.4 59 1988 10.87 10.2 9.56 9.42 0 0.91 299 345 00000.33 -0.31 89 1989 14.33 13.71 11.7 10.51 0 0.85 24 328 00000.64 -0.61 59 1990 11.13 10.29 12.35 10.07 0 0.91 321 7 00000.42 -0.38 63 1991 25 22.71 12.39 9.9 0 0.88 359 296 00000.62 -0.57 72 1992 12 10.57 13.71 10.59 0 0.89 278 51 00000.53 -0.41 65 1993 51.67 28.83 13.45 10.41 0 0.85 297 283 00131.08 -0.96 81 1994 10 9.97 9.92 9.82 0 0.9 27 276 00000.26 -0.24 67 1995 44.67 31.57 15.89 12.14 0 0.79 112 193 00131.61 -1.26 73 1996 362.33 182.14 50.85 24.52 0 0.63 168 138 00149.27 -7.54 48 1997 30.67 20.71 13.53 11.64 0 0.84 312 1 00111.06 -0.97 79 1998 15 14.57 13.47 12.42 0 0.86 58 84 00000.98 -0.93 57 1999 16 15.86 15.27 13.81 0 0.9 308 133 00001.03 -1.21 43 2000 15.33 14.14 13.97 12.62 0 0.75 271 45 00001.01 -1.07 41 2001 14.67 14 11.8 10.92 0 0.85 287 85 00000.57 -0.71 75

01/05/2004 Page 3 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow)

Non-Parametric IHA Scorecard

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Watershed area 1.00 Mean annual flow 27.52 9.36 Mean flow/area 27.52 9.36 Annual C. V. .93 .10 Flow predictability .39 .70 Constancy/predictability .31 .97 % of floods in 60d period .46 .46 flood-free season 69.00 135.00

MEDIANS COEFF. of DISP. DEVIATION FACTOR SIGNIFICANCE COUNT Pre Post Pre Post Medians C.V. Medians C.V. Parameter Group #1 October 1.0 8.7 1.38 .14 7.82 .90 .00 .13 November 3.2 8.7 4.47 .15 1.72 .97 .00 .06 December 9.0 8.9 2.06 .16 .01 .92 .93 .24 January 16.4 8.6 2.24 .24 .47 .89 .00 .51 February 26.9 9.2 1.01 .15 .66 .85 .00 .07 March 41.5 9.3 .84 .30 .78 .64 .37 .33 April 63.5 9.5 .52 .18 .85 .65 .33 .46 May 61.6 9.1 1.40 .22 .85 .84 .10 .12 June 14.1 9.1 2.58 .18 .35 .93 .00 .12 July 3.1 9.0 2.10 .12 1.86 .94 .00 .05 August 1.0 8.8 1.50 .11 7.83 .92 .00 .31 September .6 8.5 1.31 .12 12.08 .91 .00 .38

Parameter Group #2 1-day minimum .3 8.0 .84 .14 31.00 .84 .00 .77 3-day minimum .3 8.0 .94 .13 29.38 .87 .00 .71 7-day minimum .3 8.0 .83 .12 24.69 .85 .00 .74 30-day minimum .4 8.2 .94 .12 19.62 .87 .00 .54 90-day minimum .8 8.5 .90 .12 9.23 .87 .00 .30 1-day maximum 241.8 16.0 1.87 1.19 .93 .37 .22 .55 3-day maximum 208.2 14.3 1.35 .99 .93 .27 .18 .63 7-day maximum 150.8 13.9 1.27 .76 .91 .40 .27 .56 30-day maximum 120.7 12.3 .77 .31 .90 .60 .28 .41 90-day maximum 78.5 10.4 .80 .28 .87 .65 .20 .25 Number of zero days .0 .0 .00 .00 999999.00 999999.00 .00 .00 Base flow .0 .9 .60 .17 66.13 .71 .00 .90

Parameter Group #3 Date of minimum 271.0 287.0 .07 .28 .09 2.81 .06 .01 Date of maximum 73.0 44.0 .28 .29 .16 .05 .39 .87

Parameter Group #4 Low pulse count 4.0 .0 .25 .00 1.00 1.00 .03 .00 Low pulse duration 18.0 .0 1.04 .00 1.00 1.00 .06 .01 High pulse count 7.0 .0 .86 .00 1.00 1.00 .37 .38 High pulse duration 11.0 .0 .90 .00 1.00 1.00 .21 .19 The low pulse threshold is 1.46 The high pulse level is 33.40

Parameter Group #5 Rise rate 9.2 .6 1.56 1.10 .93 .30 .16 .62 Fall rate -5.4 -.5 -1.39 -1.27 .90 .09 .05 .87 Number of reversals 114.0 63.0 .15 .33 .45 1.24 .00 .00

01/05/2004 Page 4 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow)

Variance Data, Box and Whisker Format

October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

Pre-Impact Distribution 1-day min 0.19 0.71 0.96 1.42 2.92 9.95 18.25 9.64 2.31 0.45 0.15 0.18 0.09 0.1 0.11 0.14 0.18 25 pctile 0.74 1.88 3.57 6.6 15.3 32.8 45.75 33.06 5.29 1.06 0.41 0.34 0.17 0.17 0.19 0.26 0.42 Median 0.99 3.21 8.96 16.37 26.86 41.55 63.55 61.61 14.07 3.14 0.99 0.65 0.25 0.26 0.31 0.4 0.83 75 pctile 2.1 16.22 22.03 43.27 42.42 67.71 78.94 119.37 41.61 7.64 1.89 1.19 0.38 0.42 0.44 0.64 1.17 1-day max 26.04 120.08 122.27 150.04 187.57 124.29 113.46 162.13 146.13 40.23 7.45 5.83 1.4 1.4 1.47 2.32 4.08

Post-Impact Distribution 1-day min 3.93 4 4.45 4.61 5.12 4.67 4.27 4.64 4.13 4.3 4.09 3.99 3.6 3.63 3.73 3.88 3.93 25 pctile 8.34 8.35 8.48 8.37 8.25 8.04 8.5 8.72 8.29 8.32 8.15 8.2 7.2 7.3 7.41 7.72 7.87 Median 8.71 8.74 8.9 8.62 9.18 9.26 9.46 9.08 9.12 8.98 8.76 8.48 8 8 8 8.24 8.54 75 pctile 9.54 9.67 9.94 10.45 9.61 10.84 10.22 10.73 9.9 9.4 9.14 9.18 8.3 8.3 8.39 8.7 8.9 1-day max 13.31 11.83 23.91 13.03 12.79 11.65 13.6 48.71 13.57 15.69 12 12.03 11 11 11 11.2 11.54

1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

Pre-Impact Distribution 1-day min 44.95 40.41 34.47 20.01 16.31 0 0.01 210 11331.67 1.8 -14.27 94 25 pctile 119.35 94.66 84.17 60.03 42.42 0 0.01 248 13 3 12.25 5 7 4.01 -9.55 107 Median 241.81 208.21 150.76 120.66 78.5 0 0.01 271 73 4 18 7 11 9.18 -5.37 114 75 pctile 571.74 375.63 275.41 152.78 105.08 0 0.02 275 114 4 31 11 16.9 18.35 -2.09 124 1-day max 1429.9 1094.54 616.48 243.14 132.74 0 0.03 328 364 6 60 13 23.33 32.89 -1.26 134

Post-Impact Distribution 1-day min 9.5 9.1 8.93 8.51 8.42 0 0.57 24 1000 00.19 -7.54 41 25 pctile 12 10.87 10.2 9.92 9.26 0 0.75 218 345 0 0 0 0 0.37 -0.97 56 Median 16 14.33 13.86 12.35 10.41 0 0.85 287 44 0 0 0 0 0.62 -0.52 63 75 pctile 31 25 20.71 13.71 12.14 0 0.9 321 85 0 0 0 0 1.06 -0.31 77 1-day max 403 362.33 182.14 50.85 24.52 0 0.94 360 362 0 0 1 4 9.27 -0.2 89

01/05/2004 Page 5 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow)

IHA Percentile Data

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Pre-Impact Post-Impact 10% 25% 50% 75% 90% (75-25)/50 10% 25% 50% 75% 90% (75-25)/50

Parameter Group #1 October .39 .74 .99 2.10 5.82 1.38 8.14 8.34 8.71 9.54 12.05 .14 November .75 1.88 3.21 16.22 48.92 4.47 7.88 8.35 8.74 9.67 10.22 .15 December 2.03 3.57 8.96 22.03 102.28 2.06 7.92 8.48 8.90 9.94 11.46 .16 January 3.11 6.60 16.37 43.27 90.64 2.24 7.92 8.37 8.62 10.45 12.05 .24 February 9.42 15.30 26.86 42.42 101.09 1.01 8.01 8.25 9.18 9.61 11.76 .15 March 23.03 32.80 41.55 67.71 118.53 .84 7.83 8.04 9.26 10.84 11.62 .30 April 28.37 45.75 63.55 78.94 104.85 .52 6.86 8.50 9.46 10.22 11.94 .18 May 14.97 33.06 61.61 119.37 152.07 1.40 8.20 8.72 9.08 10.73 15.11 .22 June 2.89 5.29 14.07 41.61 98.18 2.58 8.14 8.29 9.12 9.90 12.23 .18 July .64 1.06 3.14 7.64 22.44 2.10 7.95 8.32 8.98 9.40 11.93 .12 August .21 .41 .99 1.89 2.96 1.50 8.00 8.15 8.76 9.14 10.33 .11 September .21 .34 .65 1.19 2.08 1.31 7.93 8.20 8.48 9.18 10.85 .12

Parameter Group #2 1-day minimum .12 .17 .25 .38 .54 .84 4.96 7.20 8.00 8.30 8.76 .14 3-day minimum .13 .17 .26 .42 .54 .94 5.05 7.30 8.00 8.30 8.79 .13 7-day minimum .16 .19 .31 .44 .56 .83 5.18 7.41 8.00 8.39 8.79 .12 30-day minimum .18 .26 .40 .64 1.43 .94 5.80 7.72 8.24 8.70 9.26 .12 90-day minimum .29 .42 .83 1.17 2.72 .90 6.65 7.87 8.54 8.90 9.56 .12 1-day maximum 82.10 119.35 241.81 571.74 1305.94 1.87 9.96 12.00 16.00 31.00 130.00 1.19 3-day maximum 50.60 94.66 208.21 375.63 882.70 1.35 9.67 10.87 14.33 25.00 88.93 .99 7-day maximum 44.70 84.17 150.76 275.41 489.50 1.27 9.43 10.20 13.86 20.71 45.15 .76 30-day maximum 30.12 60.03 120.66 152.78 213.41 .77 8.98 9.92 12.35 13.71 17.83 .31 90-day maximum 23.52 42.42 78.50 105.08 124.74 .80 8.84 9.26 10.41 12.14 14.13 .28 Number of zero days .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 Base flow .01 .01 .01 .02 .03 .60 .63 .75 .85 .90 .92 .17

Parameter Group #3 Date of minimum 226.60 248.00 271.00 275.00 280.00 .07 109.60 218.00 287.00 321.00 24.60 .28 Date of maximum 348.40 13.00 73.00 114.00 135.00 .28 293.40 345.00 44.00 85.00 141.00 .29

Parameter Group #4 Low pulse count 1.80 3.00 4.00 4.00 4.20 .25 .00 .00 .00 .00 .00 .00 Low pulse duration 8.16 12.25 18.00 31.00 48.80 1.04 .00 .00 .00 .00 .00 .00 High pulse count 3.00 5.00 7.00 11.00 12.00 .86 .00 .00 .00 .00 1.00 .00 High pulse duration 2.36 7.00 11.00 16.90 22.29 .90 .00 .00 .00 .00 3.00 .00

Parameter Group #5 Rise rate 2.33 4.01 9.18 18.35 24.85 1.56 .26 .37 .62 1.06 2.43 1.10 Fall rate -12.31 -9.55 -5.37 -2.09 -1.49 -1.39 -1.72 -.97 -.52 -.31 -.26 -1.27 Number of reversals 97.60 107.00 114.00 124.00 129.00 .15 43.80 56.00 63.00 77.00 84.00 .33

01/05/2004 Page 6 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for October Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 30 <>------<------>

10 75th percen

Cubic Feet per Second median 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 7 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for November Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 140 <>------<------>

120

100

Cubic Feet per Second 40

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 8 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for December Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 140 <>------<------>

120

100

Cubic Feet per Second 40

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 9 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for January Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 200 <>------<------>

150

100 Cubic Feet per Second 50

75th percen median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 earY

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 10 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for February Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 200 <>------<------>

150

100 Cubic Feet per Second 50

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 earY

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 11 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for March Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 140 <>------<------>

120

100

Cubic Feet per Second 40

20 75th percen median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 12 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for April Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 120 <>------<------>

100

40 Cubic Feet per Second

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 13 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for May Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 200 <>------<------>

150

100 Cubic Feet per Second 50

75th percen median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 14 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for June Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 160 <>------<------>

140

120

100

60 Cubic Feet per Second 40

20 75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 15 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for July Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 50 <>------<------>

20 Cubic Feet per Second

75th percen 10 median 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 16 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for August Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 14 <>------<------>

10 75th percen median

8 25th percen

Cubic Feet per Second 4

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 17 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Average flow for September Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 14 <>------<------>

10 75th percen median 8 25th percen

Cubic Feet per Second 4

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 18 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 1-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 12 <>------<------>

75th percen 8 median

25th percen

4 Cubic Feet per Second

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 19 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 3-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 12 <>------<------>

75th percen 8 median

25th percen

4 Cubic Feet per Second

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 20 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 7-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 12 <>------<------>

75th percen 8 median 25th percen

4 Cubic Feet per Second

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 21 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 30-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 12 <>------<------>

75th percen median 8 25th percen

4 Cubic Feet per Second

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 22 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 90-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 12 <>------<------>

75th percen median 8 25th percen

4 Cubic Feet per Second

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 23 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 1-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1600 <>------<------>

1400

1200

1000

800

600 Cubic Feet per Second 400

200

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 24 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 3-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1200 <>------<------>

1000

800

600

400 Cubic Feet per Second

200

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 25 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 7-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 700 <>------<------>

600

500

400

300

Cubic Feet per Second 200

100

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 26 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 30-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 250 <>------<------>

200

150

100 Cubic Feet per Second

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 27 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 140 <>------<------>

120

100

Cubic Feet per Second 40

20 75th percen median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 28 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Zero streamflow days Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 10 <>------<------>

5 Number 4

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 29 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Base Flow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1.0 <>------<------> 75th percen 0.9 median 0.8 25th percen 0.7

0.6

0.5

0.4

Cubic Feet per Second 0.3

0.2

0.1

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 30 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Date of minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

75th percen

300 median

25th percen 200 Julian Day

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 31 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Date of maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

25th percen

300

200 Julian Day

100 75th percen

median

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 32 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Low Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6 <>------<------>

3 Number

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 33 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Low Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 70 <>------<------>

40 Days 30

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 34 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam High Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 14 <>------<------>

Number 6

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 35 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam High Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 25 <>------<------>

15 Days

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 36 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Rise Rate Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 CFS/Day

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 37 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Fall Rate

0 75th percen 1875Pre-Impact<>------Period 1901 Post-Impact < 1975------Period 2001 > median 25th percen -2

-4

-6

-8 CFS/Day

-10

-12

-14

-16 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 38 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) Standard IHA 4295 Gerle Ck below Loon Lake Dam Pre-Impact PeriodReversals Post-Impact Period

1875 1901 1975 2001

140 <>------<------>

130

120

110

100

90 Number

80 75th percen

70 median 60 25th percen 50

40 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.ann, C:\Iha2\Loon\Loon.baw

01/05/2004 Page 39 of 40 Analysis 1 - Gerle Creek below Loon Lake Reservoir (Unregulated Flow) versus 4295 Gerle Creek below Loon Lake Dam (Regulated Flow) 4295 Gerle Ck below Loon Lake Dam

1600

1400

1200

1000

800

600 Cubic Feet per Second 400

200

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Iha2\Loon\Loon.dat

01/05/2004 Page 40 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Errors

No Errors

01/08/2004 Page 1 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

IHA Annual Summary Statistics

Year October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min 1875 7.31 18.56 16.51 32.26 115.98 177.21 180.81 793.18 288.07 46.77 12.9 3.78 2.83 2.9 2.91 3.78 12.69 1876 48.88 64.1 46.86 44.23 58.44 114.7 156.44 91.03 15.55 3.44 4.41 3.38 1.83 1.93 2.11 2.56 3.58 1877 3.85 4.07 10.06 20.84 35.71 38.81 72.06 95.57 32.11 4.03 1.3 1.49 0.76 0.8 0.82 1.28 1.53 1878 1.93 9.12 168.97 224.24 143.49 420.71 413.72 496.82 213.43 37.43 10.57 6.66 1.51 1.51 1.53 1.91 7.73 1879 7.31 18.56 16.51 32.26 115.98 177.21 180.81 793.18 288.07 46.77 12.9 3.78 2.83 2.48 2.38 2.96 8.85 1880 10.54 56.36 68.32 851.15 364.54 169.34 405.56 362.43 139.83 38.71 8.63 3.1 2.24 2.3 2.31 2.71 4.3 1881 3.76 8.68 20.04 44.41 123.3 169.17 337.16 149.52 29.44 3.76 1.81 2.13 1.44 1.48 1.53 1.8 2.28 1882 7.36 442.38 595.13 149.3 568.32 355.16 535.63 518.62 190.16 45.16 14.45 40.17 2.3 2.55 3.15 6.95 25.28 1883 144.6 181.46 197.05 149.93 219.69 423.29 295.52 938.28 735.82 193.55 32.26 9.33 5.17 5.21 5.57 8.11 17.01 1884 15.34 556.46 562.65 183.38 156.11 292.11 269.25 257.35 88.21 31.08 6.33 3.3 2.9 2.92 3.01 3.3 6.12 1885 9.29 134.4 63.66 54.7 84.47 134.75 463.16 202.68 38.61 5.02 3.14 4.22 2.47 2.47 2.54 2.87 3.81 1886 6.46 36.58 132.6 334.54 1127.42 623.51 318.84 217.19 66.67 25.81 6.27 7.05 2.71 2.82 3 3.47 7.5 1887 10.03 7.86 19.03 20.94 105.25 171.21 248.95 94.65 16.96 5.54 2.55 2.76 2.36 2.3 2.32 2.53 2.93 1888 4.09 10.11 43.37 104.78 88.9 131.8 138.75 66.62 28.79 4.53 2.33 2.33 1.96 1.97 2.04 2.15 2.4 1889 2.58 58.17 44.35 42.72 100.89 649.61 552.89 231.24 95.33 14.17 4.64 4.45 1.94 1.95 1.98 2.57 5.2 1890 11.9 19.25 33.6 88.47 69.45 234.52 293.32 162.27 59.75 10.85 2.97 2.7 2.23 2.24 2.28 2.47 3.1 1891 3.83 6.17 8.39 12.9 22.28 199.06 316.53 334.55 95.67 17.85 4.41 2.5 2.15 2.19 2.2 2.35 3.58 1892 7.59 14.9 13.56 16.13 112.52 213.69 238.47 42.85 16.89 5.14 2.26 2.02 1.81 1.83 1.87 2.01 2.31 1893 6.1 10.37 52.49 223.24 162.07 525.49 559.99 601.57 281.35 43.29 12.17 3.8 1.98 2.09 2.18 3.57 5.04 1894 5.68 6.07 17.11 25.6 47.15 185.34 210.32 149.25 22.94 4.18 1.78 2.09 1.31 1.41 1.52 1.78 2.23 1895 3.41 43.65 64.15 460.53 258.52 686.94 605.78 864.9 483.56 180.65 41.61 8.49 2.14 2.26 2.74 3.37 7.49 1896 6.11 8.07 172.25 152.28 618.51 355.79 520.32 593.7 82.74 20.1 8.4 3.73 3.15 3.12 2.92 3.16 4.86 1897 4.33 101.83 670.67 952.77 171.38 291.6 313.78 176.46 74.24 22.75 5.98 3.14 2.47 2.52 2.57 3.12 5.27 1898 6.92 25.14 37.54 279.94 199.9 421.7 409.45 645.53 662.44 108.18 12.22 5.66 3 3.35 3.6 5.46 8.47 1899 8 65.9 95.85 224.87 273.14 260.53 395.52 608.92 202.62 30.92 8.94 3.49 2.8 2.82 2.96 3.38 6.07 1900 7.13 17.28 14.95 245.04 316.19 272.96 452.71 314.51 60.93 16.34 3.41 3.18 2.34 2.41 2.44 2.68 3.69 1901 5.17 16.54 29.58 23.82 39.98 213.07 277.95 181.72 10.55 3.51 1.92 1.69 1.5 1.53 1.54 1.67 2.33 1975 9.86 6.03 6.11 6.31 7.7 9.63 9.65 23.2 10.88 12 11.9 10.51 5.3 5.33 5.44 5.74 6.06 1976 11.35 6.03 5.72 5.48 6 6.03 5.26 5.25 5.1 5.66 6.18 6.1 4.8 4.83 4.86 5.05 5.19 1977 5.77 5.22 5.08 5.26 5.31 3.11 2.35 2.42 2.29 2.36 2.03 1.99 1.5 1.53 1.7 1.95 2.07 1978 2.4 2.75 5.59 8.96 5.64 10.05 10.01 10.95 10.7 9.99 9.99 11.19 1.8 2.07 2.19 2.39 3.48 1979 9.86 6.03 6.11 6.31 7.7 9.63 9.65 23.2 10.88 12 11.9 10.51 5.3 5.33 5.44 5.74 6.06 1980 10.48 5.87 8.53 483.91 60.17 10.25 9.72 10.51 10.5 10.03 9.59 9.55 4.6 4.67 4.79 5.62 7.45 1981 11.3 5.83 5.81 5.72 6.55 7.43 5.62 5.43 5.24 5.25 5.11 7.24 4.7 4.73 4.77 5.02 5.2 1982 5.33 100.56 189.24 8.73 197.71 13.61 140.88 69.35 12.04 9.82 10.22 22.26 4.4 4.53 4.63 5.16 10.17 1983 21.67 11.2 19.14 8.56 11.08 61.39 10.28 125.29 248.7 41.34 12.48 11.63 4.8 4.97 5.06 7.1 11.16 1984 11.06 268.03 248.15 7.03 7.07 11.69 5.54 11.1 10.67 10.09 10.57 10.77 4.3 4.47 4.77 5.49 8.15 1985 10.9 8.2 6.04 5.6 7.52 6.79 7.97 10.19 10.38 11.12 11.55 11.66 4 4.47 4.79 5.49 6.34 1986 11.42 6.43 8 43.32 524.11 130.27 7.22 11.52 10.57 10.9 11 13.37 5 5.07 5.4 6.4 8.11 1987 12.39 5.85 5.6 5.75 10.31 8.04 5.74 5.58 5.88 5.68 5.57 5.52 4.8 4.97 5.13 5.42 5.54 1988 6.07 6.02 6.26 7.5 6.67 5.77 5.96 5.85 5.97 5.83 5.95 5.63 5 5.1 5.21 5.42 5.68 1989 5.65 6.48 5.79 6.23 6.79 21.55 8.08 11.97 11.8 11.09 11.13 11.33 5 5.07 5.23 5.57 5.96 1990 11.65 6.58 6.02 6.88 7.15 7.75 6.06 6.49 6.2 6.16 6.05 5.57 5 5.07 5.17 5.32 5.54 1991 5.89 5.36 5.36 5.42 6.12 37.99 8.66 5.61 6.43 6.06 6.37 6.01 4.8 5 5.19 5.32 5.38 1992 6.98 5.72 5.53 5.97 8.48 7.82 5.78 6.15 6.43 5.64 5.69 5.59 5.1 5.13 5.23 5.48 5.61 1993 6 5.55 7.61 12.9 8.9 25.04 11.41 17.48 15.6 11.06 11.29 11.2 5.2 5.2 5.34 5.52 6.33 1994 11.29 6.59 6.03 5.84 6.62 7.55 5.92 6.22 6.23 6.92 6.15 6.11 5.1 5.23 5.4 5.7 6.02 1995 6.28 6.75 8.41 73.05 7.64 98.35 53.91 100.81 52.83 11.94 12.19 11.7 5.7 5.7 5.7 6.25 7.16 1996 11 5.97 26.74 8.95 120.12 13.71 13.59 276.23 11.77 10.87 11.23 11.67 5.7 5.7 5.71 5.85 10.28 1997 11.48 8.05 157.53 530.45 9.46 6.63 6.7 11.81 13.17 12.42 12.06 11.97 5.3 5.43 5.77 6.12 7.53 1998 12.74 7.28 7.8 22.77 13.89 55.45 13.87 15.74 12.67 11.1 10.84 11.03 6.4 6.43 6.49 7.2 8.74 1999 11.58 7.83 8.43 10.29 17.28 10.67 9.06 11.1 11.07 11.19 11.26 11.3 6.1 6.17 6.36 7.48 8.42 2000 11.26 7.59 7.06 30.31 30.52 9.63 8.39 14.48 11.37 11.81 11.48 12.73 5.5 5.73 6.14 6.72 7.97 2001 12.13 6.88 7.35 7 7.29 10.59 10.19 7.08 7.66 7.35 6.82 7.55 5.1 5.23 5.56 6.74 7.03

01/08/2004 Page 2 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

IHA Annual Summary Statistics (Cont)

Year 1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

1875 1214.6 1162.11 1114.01 846.59 439.01 0 0.02 271 135 3 20 11 6.82 28.62 -21.22 141 1876 543.08 259.43 234.19 164.77 125.3 0 0.04 226 300 4 22.25 6 2.33 15.93 -8.21 135 1877 181.9 160.41 136.02 97.25 72.43 0 0.03 228 100 2 46 1 1 7.13 -5.64 117 1878 1065.52 814.46 634.42 578.75 449.72 0 0.01 280 364 4 10.5 9 14.67 48.64 -32.13 126 1879 1214.6 1162.11 1114.01 846.59 439.01 0 0.02 271 135 3 11 11 6.82 28.43 -21.22 141 1880 7372.06 4970.07 2887.99 890.65 472.27 0 0.01 275 13 2 24 12 9.75 103.16 -47.45 101 1881 536.46 452.91 409.65 340.74 338.69 0 0.02 228 118 5 20.8 6 8.67 20.53 -12.49 128 1882 4949.38 3525.5 1836.15 724.32 552.84 0 0.01 276 355 3 9 7 21.57 163.72 -60.09 110 1883 2092.84 1607.03 1552.38 1207.66 673.93 0 0.02 265 74 2 8.5 11 15.27 86.64 -42.49 99 1884 2623.33 1882.18 1489.9 604.84 441.5 0 0.01 268 322 3 25 11 13.73 88.06 -43.17 122 1885 725.9 700.1 658.18 472.6 270.54 0 0.03 240 106 4 23.75 8 6.75 14.96 -10.15 122 1886 6667.29 5347.39 3309.24 1404.63 695.12 0 0.01 244 49 3 16.67 8 15.88 115.3 -64.21 115 1887 929.67 473.37 337.83 248.95 189.71 0 0.04 224 44 4 31 8 5 15.96 -9.91 126 1888 640.81 286.8 205.83 141.31 123.06 0 0.04 251 5 3 32.67 7 1.71 12.98 -9.74 119 1889 1506.41 1339.84 1138.12 734.72 488.76 0 0.01 276 69 4 14.25 7 12.86 34.72 -24.49 124 1890 628.84 469.39 376.6 301.71 231.05 0 0.03 256 152 2 36 6 10 18.79 -14.16 113 1891 2287.42 1117.29 599.06 350.85 288.26 0 0.03 269 64 5 21.6 2 34.5 26.9 -20.78 114 1892 429.14 413.88 380.52 282.8 194.54 0 0.03 224 93 2 45 6 8.33 12.93 -6.73 121 1893 1579.67 1256.63 908 671.38 597.8 0 0.01 275 78 3 14 8 16.13 51.5 -32.72 126 1894 335.97 306.99 285.04 220.33 186.7 0 0.03 228 128 3 45.33 9 5.11 10.29 -6.66 130 1895 2903.12 2549.62 1870.8 970.58 757.85 0 0.01 276 14 2 8.5 6 29.83 98.89 -59.1 100 1896 2771.27 2112.51 1325.22 681.04 511.28 0 0.01 271 36 5 13 5 25.4 112.74 -45.54 97 1897 8682.42 6357.88 3771.83 1311.79 622.73 0 0.01 274 2 4 18.25 9 15.11 131.32 -63.3 99 1898 2131.77 1766.58 1136.02 725 627.36 0 0.02 275 84 5 9.2 7 19 59.69 -35.76 99 1899 1053.86 918.44 753.26 614.89 428.66 0 0.02 274 18 3 15.67 10 11.9 52.22 -28.67 116 1900 2018.36 1156.49 700.77 460.01 383.1 0 0.02 238 45 2 30.5 6 18.33 51.58 -29.8 125 1901 570.78 544.38 466.85 326.12 228.04 0 0.02 221 86 2 52 2 24 12.12 -8.87 157 1975 85 65.67 53.57 23.64 15.59 0 0.53 2 135 13 9.62 0 0 2.42 -2.16 101 1976 16 13.67 12.57 11.4 7.74 0 0.79 93 300 5 66 0 0 0.41 -0.37 115 1977 8.7 6.9 6.04 5.77 5.36 0 0.47 203 52 2 110.5 0 0 0.33 -0.26 94 1978 87 36.33 20.41 13.18 11.36 0 0.27 278 116 15 6.4 0 0 2.81 -1.94 93 1979 85 65.67 53.57 23.64 15.59 0 0.53 2 135 13 9.62 0 0 2.42 -2.16 101 1980 5990 3923.33 2084.14 502.34 190.33 0 0.09 317 13 13 7.77 2 4.5 70.05 -53.29 107 1981 19 13.87 12.29 11.49 99.94 0 0.75 124 85 10 31.8 0 0 0.95 -0.67 123 1982 2990 1841 795.71 257.18 151.55 0 0.07 308 47 8 6.38 8 2.5 98.58 -66.98 114 1983 1390 514.33 357 259.03 169.18 0 0.1 312 73 10 8.3 8 4.63 33.57 -25.15 111 1984 2600 1893.33 1050 268.98 178.39 0 0.09 120 322 9 13.56 4 3.75 91.57 -46.4 100 1985 37 18.53 13.43 12.2 11.58 0 0.53 309 40 7 21.86 0 0 1.27 -0.98 109 1986 5380 4100 1979.43 613.9 222.85 0 0.09 307 48 12 8.83 3 4.33 145.8 -71.2 79 1987 94 39.67 21.94 12.43 8.02 0 0.75 262 44 3 104.33 0 0 1.25 -1 115 1988 16 10.83 9.63 7.61 6.87 0 0.85 1 8 10 34.6 0 0 0.62 -0.45 125 1989 167 72.67 46.71 22.8 14.07 0 0.53 309 68 5 27.6 0 0 3.71 -2.94 100 1990 16 15 13.43 11.67 8.14 0 0.75 322 297 12 25.25 0 0 0.68 -0.51 121 1991 791 317 141.6 39.13 17.94 0 0.59 133 64 6 32 1 1 6.46 -6.17 121 1992 21 16 12.63 9.63 7.43 0 0.83 309 51 3 105.67 0 0 0.51 -0.42 130 1993 301 123 63.57 26.89 20.1 0 0.44 275 77 9 10.11 2 1 8.28 -6.3 82 1994 13 12 11.71 11.3 8.03 0 0.79 96 289 4 78.75 0 0 0.47 -0.42 152 1995 2090 1099 560.86 142.3 86.71 0 0.15 286 122 7 13.43 5 2.2 52.42 -42.06 127 1996 3200 2223.33 1170.71 285.29 104.15 0 0.13 307 137 4 17.5 3 3.33 94.92 -53.79 93 1997 8050 5520 2644.29 683.91 239.94 0 0.09 83 1 11 8.91 3 3 120.64 -80.75 93 1998 1210 452.33 204 57.77 31.73 0 0.4 307 84 5 10.8 2 1 18.87 -16.6 96 1999 84 51.33 30.71 18.13 12.87 0 0.58 318 40 7 10.14 0 0 2.39 -1.73 97 2000 554 219.67 102.14 51.17 23.44 0 0.45 99 45 8 11.75 2 1 13.48 -9.99 111 2001 15 13.33 12.71 12.13 9.43 0 0.68 167 85 13 19.23 0 0 0.45 -0.6 110

01/08/2004 Page 3 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Non-Parametric IHA Scorecard

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Watershed area 1.00 Mean annual flow 145.64 22.02 Mean flow/area 145.64 22.02 Annual C. V. .95 .14 Flow predictability .40 .60 Constancy/predictability .29 .91 % of floods in 60d period .46 .46 flood-free season 67.00 111.00

MEDIANS COEFF. of DISP. DEVIATION FACTOR SIGNIFICANCE COUNT Pre Post Pre Post Medians C.V. Medians C.V. Parameter Group #1 October 6.9 11.0 .75 .49 .59 .35 .03 .28 November 18.6 6.4 2.96 .27 .65 .91 .01 .44 December 44.3 6.3 2.60 .42 .86 .84 .14 .20 January 104.8 7.0 1.84 1.00 .93 .45 .18 .45 February 123.3 7.7 1.41 .94 .94 .34 .21 .69 March 234.5 10.1 1.06 1.39 .96 .31 .24 .77 April 316.5 8.4 .68 .51 .97 .25 .33 .91 May 257.4 11.1 1.76 1.02 .96 .42 .17 .57 June 82.7 10.7 2.22 .52 .87 .77 .16 .13 July 20.1 10.1 1.90 .51 .50 .73 .00 .23 August 6.0 10.6 1.61 .50 .77 .69 .00 .21 September 3.4 10.8 .57 .52 2.18 .10 .00 .66

Parameter Group #2 1-day minimum 2.2 5.0 .43 .12 1.23 .72 .00 .09 3-day minimum 2.3 5.1 .39 .12 1.21 .69 .00 .14 7-day minimum 2.3 5.2 .41 .15 1.25 .64 .00 .13 30-day minimum 2.7 5.6 .45 .17 1.06 .63 .00 .15 90-day minimum 4.9 6.3 .94 .40 .30 .57 .01 .12 1-day maximum 1214.6 94.0 1.64 22.03 .92 12.42 .11 .00 3-day maximum 1156.5 65.7 1.22 16.51 .94 12.51 .11 .00 7-day maximum 753.3 53.6 1.47 10.23 .93 5.95 .09 .00 30-day maximum 604.8 23.6 .90 10.39 .96 10.53 .05 .00 90-day maximum 439.0 15.6 .74 6.16 .96 7.32 .05 .00 Number of zero days .0 .0 .00 .00 999999.00 999999.00 .00 .00 Base flow .0 .5 .83 1.17 29.68 .42 .00 .76

Parameter Group #3 Date of minimum 268.0 307.0 .13 .41 .21 2.19 .03 .02 Date of maximum 64.0 51.0 .24 .20 .07 .17 .63 .64

Parameter Group #4 Low pulse count 3.0 8.0 .67 .88 1.67 .31 .00 .49 Low pulse duration 20.8 13.6 .87 1.65 .35 .91 .23 .04 High pulse count 7.0 .0 .43 .00 1.00 1.00 .11 .21 High pulse duration 12.9 .0 .90 .00 1.00 1.00 .11 .16 The low pulse threshold is 8.35 The high pulse level is 179.91

Parameter Group #5 Rise rate 34.7 2.8 2.08 18.43 .92 7.87 .13 .00 Fall rate -24.5 -2.2 -1.36 -19.18 .91 13.12 .19 .00 Number of reversals 121.0 109.0 .13 .23 .10 .73 .02 .01

01/08/2004 Page 4 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Variance Data, Box and Whisker Format

October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

Pre-Impact Distribution 1-day min 1.93 4.07 8.39 12.9 22.28 38.81 72.06 42.85 10.55 3.44 1.3 1.49 0.76 0.8 0.82 1.28 1.53 25 pctile 4.09 9.12 17.11 32.26 84.47 171.21 238.47 149.52 29.44 5.02 2.55 2.5 1.83 1.93 1.98 2.15 2.93 Median 6.92 18.56 44.35 104.78 123.3 234.52 316.53 257.35 82.74 20.1 5.98 3.38 2.24 2.3 2.32 2.71 4.86 75 pctile 9.29 64.1 132.6 224.87 258.52 420.71 452.71 601.57 213.43 43.29 12.17 4.45 2.8 2.82 2.92 3.38 7.5 1-day max 144.6 556.46 670.67 952.77 1127.42 686.94 605.78 938.28 735.82 193.55 41.61 40.17 5.17 5.21 5.57 8.11 25.28

Post-Impact Distribution 1-day min 2.4 2.75 5.08 5.26 5.31 3.11 2.35 2.42 2.29 2.36 2.03 1.99 1.5 1.53 1.7 1.95 2.07 25 pctile 6.07 5.85 5.79 5.84 6.67 7.55 5.92 6.15 6.23 6.06 6.15 6.1 4.7 4.73 4.79 5.32 5.54 Median 11 6.43 6.26 7.03 7.7 10.05 8.39 11.1 10.67 10.09 10.57 10.77 5 5.07 5.23 5.57 6.33 75 pctile 11.48 7.59 8.43 12.9 13.89 21.55 10.19 17.48 11.8 11.19 11.48 11.66 5.3 5.33 5.56 6.25 8.11 1-day max 21.67 268.03 248.15 530.45 524.11 130.27 140.88 276.23 248.7 41.34 12.48 22.26 6.4 6.43 6.49 7.48 11.16

1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

Pre-Impact Distribution 1-day min 181.9 160.41 136.02 97.25 72.43 0 0.01 221 2 2 8.5 1 1 7.13 -64.21 97 25 pctile 628.84 469.39 380.52 301.71 228.04 0 0.01 228 13 2 13 6 6.82 15.93 -43.17 110 Median 1214.6 1156.49 753.26 604.84 439.01 0 0.02 268 64 3 20.8 7 12.86 34.72 -24.49 121 75 pctile 2623.33 1882.18 1489.9 846.59 552.84 0 0.03 275 100 4 31 9 18.33 88.06 -9.91 126 1-day max 8682.42 6357.88 3771.83 1404.63 757.85 0 0.04 280 364 5 52 12 34.5 163.72 -5.64 157

Post-Impact Distribution 1-day min 8.7 6.9 6.04 5.77 5.36 0 0.07 1 1 2 6.38 0 0 0.33 -80.75 79 25 pctile 19 15 12.71 11.67 8.14 0 0.13 167 13 5 9.62 0 0 0.68 -42.06 96 Median 94 65.67 53.57 23.64 15.59 0 0.53 307 51 8 13.56 0 0 2.81 -2.16 109 75 pctile 2090 1099 560.86 257.18 104.15 0 0.75 317 85 12 32 3 2.5 52.42 -0.6 121 1-day max 8050 5520 2644.29 683.91 239.94 0 0.85 322 322 15 110.5 8 4.63 145.8 -0.26 152

01/08/2004 Page 5 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

IHA Percentile Data

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Pre-Impact Post-Impact 10% 25% 50% 75% 90% (75-25)/50 10% 25% 50% 75% 90% (75-25)/50

Parameter Group #1 October 3.25 4.09 6.92 9.29 22.05 .75 5.59 6.07 11.00 11.48 12.46 .49 November 6.15 9.12 18.56 64.10 233.64 2.96 5.33 5.85 6.43 7.59 29.07 .27 December 12.86 17.11 44.35 132.60 569.15 2.60 5.50 5.79 6.26 8.43 163.87 .42 January 19.90 32.26 104.78 224.87 538.65 1.84 5.47 5.84 7.03 12.90 155.22 1.00 February 39.13 84.47 123.30 258.52 578.36 1.41 5.93 6.67 7.70 13.89 135.64 .94 March 128.38 171.21 234.52 420.71 628.73 1.06 5.97 7.55 10.05 21.55 68.78 1.39 April 152.90 238.47 316.53 452.71 554.31 .68 5.48 5.92 8.39 10.19 21.88 .51 May 86.15 149.52 257.35 601.57 807.53 1.76 5.39 6.15 11.10 17.48 105.70 1.02 June 16.62 29.44 82.74 213.43 519.34 2.22 5.21 6.23 10.67 11.80 23.05 .52 July 3.71 5.02 20.10 43.29 122.67 1.90 5.56 6.06 10.09 11.19 12.08 .51 August 1.80 2.55 5.98 12.17 18.02 1.61 5.48 6.15 10.57 11.48 12.09 .50 September 1.96 2.50 3.38 4.45 8.66 .57 5.56 6.10 10.77 11.66 12.86 .52

Parameter Group #2 1-day minimum 1.41 1.83 2.24 2.80 3.03 .43 3.56 4.70 5.00 5.30 5.78 .12 3-day minimum 1.47 1.93 2.30 2.82 3.16 .39 3.99 4.73 5.07 5.33 5.82 .12 7-day minimum 1.53 1.98 2.32 2.92 3.24 .41 4.14 4.79 5.23 5.56 6.19 .15 30-day minimum 1.76 2.15 2.71 3.38 5.76 .45 4.49 5.32 5.57 6.25 7.12 .17 90-day minimum 2.27 2.93 4.86 7.50 13.56 .94 4.85 5.54 6.33 8.11 10.19 .40 1-day maximum 410.51 628.84 1214.60 2623.33 6808.24 1.64 14.60 19.00 94.00 2090.00 5502.00 22.03 3-day maximum 281.32 469.39 1156.49 1882.18 5045.53 1.22 11.77 15.00 65.67 1099.00 3958.67 16.51 7-day maximum 228.52 380.52 753.26 1489.90 2972.24 1.47 11.30 12.71 53.57 560.86 2000.37 10.23 30-day maximum 160.08 301.71 604.84 846.59 1228.49 .90 9.23 11.67 23.64 257.18 524.65 10.39 90-day maximum 124.85 228.04 439.01 552.84 678.17 .74 7.31 8.14 15.59 104.15 196.84 6.16 Number of zero days .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 Base flow .01 .01 .02 .03 .04 .83 .09 .13 .53 .75 .80 1.17

Parameter Group #3 Date of minimum 224.00 228.00 268.00 275.00 276.00 .13 98.40 167.00 307.00 317.00 2.00 .41 Date of maximum 348.40 13.00 64.00 100.00 135.00 .24 299.40 13.00 51.00 85.00 135.00 .20

Parameter Group #4 Low pulse count 2.00 2.00 3.00 4.00 5.00 .67 3.00 5.00 8.00 12.00 13.00 .88 Low pulse duration 8.90 13.00 20.80 31.00 45.47 .87 7.50 9.62 13.56 32.00 104.60 1.65 High pulse count 2.00 6.00 7.00 9.00 11.00 .43 .00 .00 .00 3.00 5.60 .00 High pulse duration 2.21 6.82 12.86 18.33 26.29 .90 .00 .00 .00 2.50 4.37 .00

Parameter Group #5 Rise rate 11.75 15.93 34.72 88.06 118.50 2.08 .44 .68 2.81 52.42 103.00 18.43 Fall rate -60.73 -43.17 -24.49 -9.91 -6.72 -1.36 -67.83 -42.06 -2.16 -.60 -.41 -19.18 Number of reversals 99.00 110.00 121.00 126.00 141.00 .13 90.80 96.00 109.00 121.00 127.60 .23

01/08/2004 Page 6 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for October Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 160 <>------<------>

140

120

100

60 Cubic Feet per Second 40

20 75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\Rubicon\rubicon.ann, P:\Framatome\IHA\Rubicon\rubicon.baw

01/08/2004 Page 7 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for November Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 600 <>------<------>

500

400

300

200 Cubic Feet per Second

100

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 8 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for December Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 700 <>------<------>

600

500

400

300

Cubic Feet per Second 200

100

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 9 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for January Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1000 <>------<------>

900

800

700

600

500

400

Cubic Feet per Second 300

200

100

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 10 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for February Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1200 <>------<------>

1000

800

600

400 Cubic Feet per Second

200

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 11 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for March Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 700 <>------<------>

600

500

400

300

Cubic Feet per Second 200

100

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 12 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for April Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 700 <>------<------>

600

500

400

300

Cubic Feet per Second 200

100

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 13 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for May Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1000 <>------<------>

900

800

700

600

500

400

Cubic Feet per Second 300

200

100 75th percen median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 14 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for June Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 800 <>------<------>

700

600

500

400

300 Cubic Feet per Second 200

100

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 15 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for July Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 200 <>------<------>

150

100 Cubic Feet per Second 50

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 16 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for August Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 50 <>------<------>

20 Cubic Feet per Second 75th percen median 10

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 17 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Average flow for September Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 50 <>------<------>

20 Cubic Feet per Second 75th percen median 10

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 18 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 1-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7 <>------<------>

75th percen 5 median 25th percen

Cubic Feet per Second 2

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 19 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 3-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7 <>------<------>

75th percen median 5 25th percen

Cubic Feet per Second 2

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 20 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 7-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7 <>------<------>

6 75th percen median 5 25th percen

Cubic Feet per Second 2

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 21 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 30-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 9 <>------<------>

75th percen 6 median 25th percen 5

4 Cubic Feet per Second 3

1 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 22 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 90-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 30 <>------<------>

10 Cubic Feet per Second 75th percen

median 5 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 23 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 1-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 9000 <>------<------>

8000

7000

6000

5000

4000

3000 Cubic Feet per Second 75th percen 2000

1000

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 24 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 3-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7000 <>------<------>

6000

5000

4000

3000

Cubic Feet per Second 2000

75th percen 1000

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 25 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 7-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000 Cubic Feet per Second 1000

75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 26 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 30-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1600 <>------<------>

1400

1200

1000

800

600 Cubic Feet per Second 400

75th percen 200

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 27 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 800 <>------<------>

700

600

500

400

300 Cubic Feet per Second 200

75th percen 100

median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 28 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Zero streamflow days Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 29 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Base Flow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 0.9 <>------<------>

0.8 75th percen

0.7

0.6

median 0.5

0.4

0.3 Cubic Feet per Second

0.2

0.1 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 30 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Date of minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

75th percen median 300

200

Julian Day 25th percen

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 31 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Date of maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Julian Day

100 75th percen

median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 32 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Low Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 16 <>------<------>

75th percen 12

Number 8 median

25th percen 4

2 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 33 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Low Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 120 <>------<------>

100

60 Days

40 75th percen

20 median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 34 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek High Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 14 <>------<------>

Number 6

4 75th percen

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 35 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek High Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 Days

75th percen

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 36 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Rise Rate Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 200 <>------<------>

150

100 CFS/Day

75th percen 50

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 37 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA 4300 South Fork Rubicon Below Gerle Creek Fall Rate

0 75th percen 1875Pre-Impact<>------Period 1901 Post-Impact < 1975------Period 2001 > median

-10

-20

-30

-40 25th percen

CFS/Day -50

-60

-70

-80

-90 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 38 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

Standard IHA Pre-Impact4300 PeriodSouth Fork Rubicon Below Gerle Post-ImpactCreek Period Reversals 1875 1901 1975 2001

160 <>------<------>

150

140

130

75th percen 120

Number 110 median

100 25th percen 90

70 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.ann, P:\Framatome\IHA\2-Rubicon\rubicon.baw

01/08/2004 Page 39 of 40 Analysis 2 - South Fork Rubicon Below Gerle Creek (Unregulated) versus 4300 South Fork Rubicon Below Gerle Creek (Regulated)

4300 South Fork Rubicon Below Gerle Creek

9000

8000

7000

6000

5000

4000

3000 Cubic Feet per Second

2000

1000

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\2-Rubicon\rubicon.dat

01/08/2004 Page 40 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Errors

No Errors

01/08/2004 Page 1 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

IHA Annual Summary Statistics

Year October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

1886 6.41 8.89 34.32 99.96 277.62 283.76 229.66 324.47 187.64 47.21 13.19 11.08 3.99 4.09 4.17 6.16 8.89 1887 11.87 6.71 7.14 9.77 33.13 35.67 160.13 111.84 22.4 5.67 2.67 2.21 1.79 1.83 1.91 2.15 2.66 1888 3.34 6.89 32.45 28.11 33.6 67.11 102.3 81.73 31.02 5.1 2.3 2.1 1.42 1.42 1.56 1.69 1.95 1889 1.65 18.76 18.25 15.76 28.67 175.15 297.76 227.46 124.09 15.24 5.24 6.17 1.34 1.46 1.49 1.64 5.83 1890 12.01 13.79 14.92 28.49 24.01 65.01 175.34 107.85 80.59 11.68 3.24 2.86 1.97 2.01 2.07 2.44 3.07 1891 3.27 3.83 4.19 4.7 11.65 64.39 85.14 204.5 120.64 20.01 5 2.48 1.82 1.89 1.92 2.02 3.63 1892 6.87 10.62 9.61 9.51 39.56 56.01 156.93 72.07 23.76 5.57 2.2 1.61 1.22 1.25 1.31 1.58 2 1893 5.08 7.2 23.23 43.02 40.03 134.15 216.57 462.04 242.53 66.64 14.79 4.93 1.46 1.63 1.76 4.45 4.85 1894 5.5 4.41 13.34 17.62 21.5 50.01 117.76 129.85 24.13 4.17 1.61 1.72 1.18 1.25 1.32 1.44 1.98 1895 2.73 12.03 15.68 150.11 88.94 189.26 213.31 439.95 550.64 278.15 51.33 13.79 1.8 2.03 2.25 2.73 7.66 1896 6.33 5.31 74.16 66.01 161.84 129.61 240.36 471.35 173.35 42.24 10.01 4.83 3.73 3.66 3.28 3.13 4.63 1897 3.64 62.04 192.34 454.39 95.53 139.01 219.94 250.49 124.84 24.44 7 3.69 2.09 2.15 2.29 3.47 4.97 1898 5.94 12.86 17.11 114.38 67.82 140.17 161.3 272.67 563.23 188.62 19.35 8.44 2.6 3.15 3.55 5.05 8.14 1899 6.4 22.16 39.07 84.53 81.53 80.47 144.85 425.64 270.79 47.43 10.77 4.21 2.93 2.94 2.84 2.92 5.09 1900 4.74 8 8.51 48.7 73.66 83.3 219.82 301.98 88.4 15.64 4.07 3.76 2.55 2.55 2.38 2.8 3.89 1901 4.54 6.89 9.21 9.44 11.45 67.78 104.98 168.93 14.75 4.3 1.91 1.85 1.37 1.47 1.49 1.63 2.62 1986 12.48 8.24 4.85 3.86 7.03 54.98 4.01 9.49 9.66 16 16.06 16.43 2.8 3.2 3.46 3.83 4.51 1987 12.65 8.51 5.06 3.65 3.97 4.13 6.07 6.84 6.51 5.46 5.72 5.53 3 3.07 3.13 3.58 3.91 1988 5.83 6.15 5.4 5.73 5.74 6.05 5.62 5.49 5.54 5.59 5.52 5.51 5 5 5.07 5.32 5.44 1989 5.32 6.07 5.49 5.8 6.21 7.24 4.06 9.72 8.74 16 16.13 16.07 3 3 3.04 4.04 5.62 1990 13.9 8.47 4.78 5.11 4.81 4.29 6.13 6.68 5.87 5.76 5.96 6 3.3 3.3 3.36 4.11 4.71 1991 5.74 5.72 5.88 5.72 5.96 6.58 6.1 6.24 5.91 5.94 5.79 5.95 5.1 5.27 5.37 5.58 5.77 1992 6.02 5.78 5.55 5.61 6.15 6.06 6.08 6.25 6.01 5.71 5.21 5.29 5.1 5.1 5.1 5.14 5.29 1993 5.48 5.65 6.12 6.84 6.11 7.04 4.37 9.67 8.6 16 16.1 16 3.5 3.5 3.61 4.37 5.76 1994 12.45 7.95 4.78 3.65 4.14 4.33 5.02 5.61 5.55 6.1 6.2 6.2 3.1 3.13 3.21 3.49 4.01 1995 5.74 5.7 6.03 6.98 6.27 7.78 5.33 9.5 167.82 61.9 16.23 15.8 3.6 3.6 3.64 5.33 5.81 1996 13.45 8.32 5.53 4.54 5.99 6.15 6.07 87.95 10.38 17.52 17.77 17.57 3.9 3.93 3.97 4.5 5.16 1997 13.52 11.21 6.03 183.63 5.94 5.18 5.12 9.35 14.39 16.9 18.19 17.5 4.6 4.6 4.61 4.71 5.39 1998 14.32 8.82 5.95 5.54 4.87 6.07 5.7 10.03 85.82 25 16 17.17 4 4.1 4.2 4.73 5.36 1999 13.35 8.5 5.91 4.83 5.43 5.25 5.08 11.26 12.3 15.77 15.84 15.8 3.9 4 4.39 4.71 5.11 2000 13.16 9.47 4.97 4.66 4.83 4.96 4.73 9.69 10.12 17.39 16.48 15.93 3.7 3.7 3.79 4.45 4.8 2001 13.52 8.11 5 4.13 4.35 4.9 5.16 6.07 6.26 6.02 6.06 6.46 3.9 2.47 1.06 0.25 0.08

01/08/2004 Page 2 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

IHA Annual Summary Statistics (Cont)

Year 1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

1886 2025.63 1529.43 830.27 448.23 295.2 0 0.03 256 68 4 10.75 6 24.67 51 -24.79 93 1887 292.3 229.62 217.5 183.8 104.42 0 0.06 274 44 4 22 2 20.5 5.89 -3.69 116 1888 195.8 134.2 123.43 104.02 84.09 0 0.05 251 345 4 27 7 4.14 6.17 -4.18 113 1889 611.01 468.83 401.47 310.25 241.71 0 0.02 306 68 6 9.33 4 25.75 16.42 -9.55 122 1890 279.43 227.88 201.37 175.34 130.13 0 0.05 256 114 3 27.33 5 12.4 8.17 -4.18 101 1891 752.69 367.65 286.87 224.42 138.67 0 0.04 269 64 6 24.33 4 14.25 12.51 -7.76 108 1892 306.16 238.99 204.18 156.93 102.07 0 0.04 273 108 4 20.25 3 14.67 6.83 -4.03 129 1893 627.5 574.64 535.19 465.67 315.76 0 0.02 288 152 7 7.14 3 40 23.65 -11.45 112 1894 246.08 232.47 210.77 159.65 101.27 0 0.04 254 132 4 34.25 5 7.2 5.62 -3.33 118 1895 1557.86 1078.76 779.74 564.02 448.5 0 0.01 276 122 1 0 6 27.17 47.46 -24.77 90 1896 1684.95 1392.27 936.61 498.87 307.71 0 0.03 271 137 5 15.8 6 23.33 47.35 -18.16 89 1897 5084.66 3266.45 1753.2 540.16 259.86 0 0.02 284 1 6 10.33 8 18.75 69.43 -33.42 103 1898 910.44 718.63 687.13 563.23 368.06 0 0.03 275 84 4 8 5 25.6 28.85 -14.81 95 1899 806.57 791.49 718.81 459.14 287.58 0 0.03 274 147 5 10 7 14.43 22.87 -11.34 104 1900 784.45 538.76 421.45 310.87 214.93 0 0.03 274 129 7 11.29 6 15.67 18.48 -10.86 123 1901 293.1 285.62 264.38 207.37 117.01 0 0.04 242 129 7 16.43 3 14.67 5.76 -3.73 125 1986 649 481.33 226.5 59.06 23.7 0 0.25 3 68 6 23.83 1 4 9.18 -6.9 71 1987 15 13.33 13 12.63 8.82 0 0.51 11 275 5 50.8 0 0 0.31 -0.38 95 1988 6.6 6.5 6.49 6.19 5.85 0 0.89 362 325 9 36.22 0 0 0.19 -0.19 99 1989 18 16.67 16.29 16.13 16.07 0 0.34 102 231 11 10.91 0 0 0.5 -0.4 85 1990 16 14.67 14.29 13.93 9.15 0 0.52 49 275 9 29.44 0 0 0.33 -0.39 88 1991 12 9.1 7.57 6.62 6.31 0 0.9 315 64 18 14.61 0 0 0.31 -0.28 83 1992 10 7.47 6.79 6.41 6.17 0 0.88 8 113 12 27.75 0 0 0.29 -0.24 86 1993 18 16.67 16.29 16.1 16.03 0 0.4 112 224 9 8.33 0 0 0.5 -0.41 83 1994 14 13.33 13.14 12.43 8.48 0 0.53 22 275 6 50.33 0 0 0.23 -0.34 84 1995 451 450.33 398.86 217.93 83.42 0 0.14 108 178 10 12.4 2 12.5 7.32 -6.22 95 1996 1250 768.67 355 90.67 40.66 0 0.24 11 137 12 11.67 1 4 20.46 -16.5 62 1997 2840 1751.67 789.29 189.69 70.45 0 0.18 335 2 7 16.71 2 2.5 43.14 -30.68 78 1998 457 382.33 228.43 98.3 43.72 0 0.25 6 173 12 11.08 2 3.5 7.97 -8.49 115 1999 16 16 16 16 15.82 0 0.44 6 190 8 18.75 0 0 0.69 -0.56 63 2000 19 18 18 17.4 16.64 0 0.39 6 309 3 53 0 0 0.8 -0.63 83 2001 15 14.33 14.14 13.53 8.97 0 0.17 7 275 6 49.17 0 0 0.25 -0.4 63

01/08/2004 Page 3 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Non-Parametric IHA Scorecard

Pre-impact period: 1886-1901 (16 years) Post-impact period: 1986-2001 (16 years)

Watershed area 1.00 Mean annual flow 76.31 4.73 Mean flow/area 76.31 4.73 Annual C. V. .99 1.25 Flow predictability .43 .61 Constancy/predictability .28 .91 WARNING: Some of the Colwell Parameters are based on < 20 years of data % of floods in 60d period .48 .54 flood-free season 84.00 175.00

MEDIANS COEFF. of DISP. DEVIATION FACTOR SIGNIFICANCE COUNT Pre Post Pre Post Medians C.V. Medians C.V. Parameter Group #1 October 5.3 12.6 .57 .62 1.37 .09 .00 .68 November 8.4 8.2 .81 .32 .03 .60 .68 .35 December 16.4 5.5 1.50 .17 .66 .88 .02 .08 January 35.8 5.3 2.37 .29 .85 .88 .10 .10 February 39.8 5.8 1.56 .23 .85 .85 .29 .14 March 81.9 6.1 .92 .33 .93 .64 .32 .72 April 168.3 5.2 .57 .24 .97 .57 .50 .96 May 239.0 9.4 1.19 .37 .96 .69 .33 .69 June 122.4 8.7 1.66 .68 .93 .59 .16 .33 July 17.8 15.9 2.34 .72 .11 .69 .36 .31 August 5.1 15.9 1.99 .65 2.11 .67 .00 .33 September 3.7 15.8 1.00 .66 3.24 .34 .00 .30

Parameter Group #2 1-day minimum 1.8 3.8 .67 .34 1.10 .49 .00 .19 3-day minimum 1.9 3.6 .71 .36 .87 .49 .00 .17 7-day minimum 2.0 3.7 .61 .35 .86 .43 .00 .22 30-day minimum 2.6 4.5 .67 .26 .73 .62 .00 .16 90-day minimum 4.3 5.2 .71 .19 .23 .72 .05 .18 1-day maximum 690.1 17.0 1.60 25.96 .98 15.23 .08 .01 3-day maximum 503.8 16.3 1.53 25.71 .97 15.76 .07 .01 7-day maximum 411.5 16.1 1.34 13.31 .96 8.92 .04 .01 30-day maximum 310.6 16.0 1.01 4.38 .95 3.34 .09 .03 90-day maximum 228.3 15.9 .86 1.75 .93 1.03 .16 .09 Number of zero days .0 .0 .00 .00 999999.00 999999.00 .00 .00 Base flow .0 .4 .68 .74 10.89 .09 .00 .95

Parameter Group #3 Date of minimum 273.5 7.5 .05 .11 .55 .95 .45 .01 Date of maximum 118.0 207.0 .19 .43 .49 1.30 .00 .00

Parameter Group #4 Low pulse count 4.5 9.0 .44 .64 1.00 .44 .00 .25 Low pulse duration 13.5 21.3 1.05 1.60 .57 .52 .14 .14 High pulse count 5.0 .0 .55 .00 1.00 1.00 .08 .07 High pulse duration 17.2 .0 .64 .00 1.00 1.00 .30 .30 The low pulse threshold is 6.22 The high pulse level is 95.45

Parameter Group #5 Rise rate 17.5 .5 2.09 15.04 .97 6.21 .03 .01 Fall rate -10.2 -.4 -1.30 -15.58 .96 10.99 .08 .01 Number of reversals 110.0 83.5 .22 .25 .24 .10 .01 .75

01/08/2004 Page 4 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Variance Data, Box and Whisker Format

October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

Pre-Impact Distribution 1-day min 1.65 3.83 4.19 4.7 11.45 35.67 85.14 72.07 14.75 4.17 1.61 1.61 1.18 1.25 1.31 1.44 1.95 25 pctile 3.41 6.76 9.31 11.27 25.17 64.55 124.53 116.34 25.85 5.6 2.39 2.13 1.38 1.46 1.51 1.65 2.63 Median 5.29 8.44 16.4 35.75 39.8 81.89 168.32 238.97 122.36 17.83 5.12 3.72 1.81 1.95 2 2.58 4.26 75 pctile 6.41 13.55 33.86 96.1 87.08 139.88 219.91 400.35 228.81 47.38 12.58 5.86 2.59 2.84 2.73 3.39 5.64 1-day max 12.01 62.04 192.34 454.39 277.62 283.76 297.76 471.35 563.23 278.15 51.33 13.79 3.99 4.09 4.17 6.16 8.89

Post-Impact Distribution 1-day min 5.32 5.65 4.78 3.65 3.97 4.13 4.01 5.49 5.54 5.46 5.21 5.29 2.8 2.47 1.06 0.25 0.08 25 pctile 5.76 5.86 4.98 4.23 4.81 4.92 4.8 6.24 5.93 5.8 5.83 5.96 3.15 3.15 3.25 3.88 4.56 Median 12.56 8.17 5.51 5.32 5.84 6.05 5.24 9.42 8.67 15.89 15.92 15.8 3.8 3.65 3.71 4.48 5.22 75 pctile 13.5 8.51 5.94 5.78 6.14 6.92 6.07 9.72 11.82 17.27 16.2 16.34 4.45 4.47 4.56 5.04 5.58 1-day max 14.32 11.21 6.12 183.63 7.03 54.98 6.13 87.95 167.82 61.9 18.19 17.57 5.1 5.27 5.37 5.58 5.81

1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

Pre-Impact Distribution 1-day min 195.8 134.2 123.43 104.02 84.09 0 0.01 242 11024.14 5.62 -33.42 89 25 pctile 292.5 234.1 212.45 177.45 107.57 0 0.02 256 68 4 9.5 3.25 14.29 6.33 -17.32 96.5 Median 690.09 503.8 411.46 310.56 228.32 0 0.03 273.5 118 4.5 13.54 5 17.21 17.45 -10.2 110 75 pctile 1396.01 1006.94 764.51 490.57 304.58 0 0.04 275.75 135.75 6 23.75 6 25.37 42.73 -4.06 121 1-day max 5084.66 3266.45 1753.2 564.02 448.5 0 0.06 306 345 7 34.25 8 40 69.43 -3.33 129

Post-Impact Distribution 1-day min 6.6 6.5 6.49 6.19 5.85 0 0.14 3 2 3 8.33 0 0 0.19 -30.68 62 25 pctile 14.25 13.33 13.04 12.48 8.57 0 0.24 3.75 119 6 11.85 0 0 0.29 -6.73 72.75 Median 17 16.33 16.14 16.05 15.93 0 0.39 7.5 207 9 21.29 0 0 0.5 -0.41 83.5 75 pctile 455.5 433.33 227.95 82.77 36.42 0 0.53 42.25 275 11.75 45.93 1 3.25 7.81 -0.35 93.25 1-day max 2840 1751.67 789.29 217.93 83.42 0 0.9 362 325 18 53 2 12.5 43.14 -0.19 115

01/08/2004 Page 5 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

IHA Percentile Data

Pre-impact period: 1886-1901 (16 years) Post-impact period: 1986-2001 (16 years)

Pre-Impact Post-Impact 10% 25% 50% 75% 90% (75-25)/50 10% 25% 50% 75% 90% (75-25)/50

Parameter Group #1 October 2.41 3.41 5.29 6.41 11.91 .57 5.43 5.76 12.56 13.50 14.03 .62 November 4.24 6.76 8.44 13.55 34.13 .81 5.69 5.86 8.17 8.51 9.99 .32 December 6.25 9.31 16.40 33.86 109.62 1.50 4.78 4.98 5.51 5.94 6.06 .17 January 8.02 11.27 35.75 96.10 241.39 2.37 3.65 4.23 5.32 5.78 59.97 .29 February 11.59 25.17 39.80 87.08 196.58 1.56 4.09 4.81 5.84 6.14 6.50 .23 March 45.70 64.55 81.89 139.88 217.61 .92 4.24 4.92 6.05 6.92 21.94 .33 April 97.15 124.53 168.32 219.91 257.58 .57 4.05 4.80 5.24 6.07 6.11 .24 May 78.83 116.34 238.97 400.35 464.83 1.19 5.57 6.24 9.42 9.72 34.27 .37 June 20.11 25.85 122.36 228.81 554.42 1.66 5.54 5.93 8.67 11.82 110.42 .68 July 4.26 5.60 17.83 47.38 215.48 2.34 5.55 5.80 15.89 17.27 36.07 .72 August 1.82 2.39 5.12 12.58 28.94 1.99 5.43 5.83 15.92 16.20 17.90 .65 September 1.69 2.13 3.72 5.86 11.89 1.00 5.44 5.96 15.80 16.34 17.52 .66

Parameter Group #2 1-day minimum 1.21 1.38 1.81 2.59 3.81 .67 2.94 3.15 3.80 4.45 5.10 .34 3-day minimum 1.25 1.46 1.95 2.84 3.79 .71 2.84 3.15 3.65 4.47 5.15 .36 7-day minimum 1.31 1.51 2.00 2.73 3.74 .61 2.45 3.25 3.71 4.56 5.18 .35 30-day minimum 1.54 1.65 2.58 3.39 5.39 .67 2.51 3.88 4.48 5.04 5.40 .26 90-day minimum 1.97 2.63 4.26 5.64 8.37 .71 2.76 4.56 5.22 5.58 5.78 .19 1-day maximum 231.00 292.50 690.09 1396.01 2943.34 1.60 8.98 14.25 17.00 455.50 1727.00 25.96 3-day maximum 199.77 234.10 503.80 1006.94 2050.54 1.53 7.18 13.33 16.33 433.33 1063.57 25.71 7-day maximum 177.99 212.45 411.46 764.51 1181.59 1.34 6.70 13.04 16.14 227.95 515.99 13.31 30-day maximum 141.06 177.45 310.56 490.57 563.47 1.01 6.34 12.48 16.05 82.77 198.16 4.38 90-day maximum 96.11 107.57 228.32 304.58 392.19 .86 6.07 8.57 15.93 36.42 74.34 1.75 Number of zero days .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 Base flow .02 .02 .03 .04 .05 .68 .16 .24 .39 .53 .90 .74

Parameter Group #3 Date of minimum 248.30 256.00 273.50 275.75 293.40 .05 329.00 3.75 7.50 42.25 109.20 .11 Date of maximum 31.10 68.00 118.00 135.75 209.90 .19 45.40 119.00 207.00 275.00 313.80 .43

Parameter Group #4 Low pulse count 2.40 4.00 4.50 6.00 7.00 .44 4.40 6.00 9.00 11.75 13.80 .64 Low pulse duration 5.00 9.50 13.54 23.75 29.41 1.05 10.14 11.85 21.29 45.93 51.46 1.60 High pulse count 2.70 3.25 5.00 6.00 7.30 .55 .00 .00 .00 1.00 2.00 .00 High pulse duration 6.28 14.29 17.21 25.37 31.02 .64 .00 .00 .00 3.25 6.55 .00

Parameter Group #5 Rise rate 5.72 6.33 17.45 42.73 56.53 2.09 .22 .29 .50 7.81 27.26 15.04 Fall rate -27.38 -17.32 -10.20 -4.06 -3.58 -1.30 -20.75 -6.73 -.41 -.35 -.22 -15.58 Number of reversals 89.70 96.50 110.00 121.00 126.20 .22 62.70 72.75 83.50 93.25 103.80 .25

01/08/2004 Page 6 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for October Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 16 <>----- <>-----

14 75th percen

median 12

6 25th percen Cubic Feet per Second 4

0 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 7 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for November Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 70 <>----- <>-----

Cubic Feet per Second 20

10 75thmedian percen 25th percen

0 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 8 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for December Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 200 <>----- <>-----

150

100 Cubic Feet per Second 50

75thmedian percen 0 25th percen 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 9 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for January Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 500 <>----- <>-----

400

300

200 Cubic Feet per Second

100

75thmedian percen 0 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 10 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for February Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 300 <>----- <>-----

250

200

150

100 Cubic Feet per Second

75thmedian percen 0 25th percen 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 11 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for March Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 300 <>----- <>-----

250

200

150

100 Cubic Feet per Second

75thmedian percen 0 25th percen 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 12 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for April Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 300 <>----- <>-----

250

200

150

100 Cubic Feet per Second

75thmedian percen 0 25th percen 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 13 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for May Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 500 <>----- <>-----

400

300

200 Cubic Feet per Second

100

75thmedian percen 0 25th percen 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 14 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for June Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 600 <>----- <>-----

500

400

300

200 Cubic Feet per Second

100

75thmedian percen 0 25th percen 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 15 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for July Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 300 <>----- <>-----

250

200

150

100 Cubic Feet per Second

75thmedian percen

0 25th percen 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 16 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for August Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 60 <>----- <>-----

20 Cubic Feet per Second 75thmedian percen

25th percen

0 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 17 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir Average flow for September Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 20 <>----- <>-----

75th percen median 15

10 Cubic Feet per Second 25th percen 5

0 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 18 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir 1-day minimum streamflow Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 6 <>----- <>-----

75th percen

4 median

3 25th percen Cubic Feet per Second

1 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 19 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4415 South Fork Silver Creek below Ice House Reservoir 3-day minimum streamflow Pre-Impact Period Post-Impact Period 1886 1901 1986 2001 6 <>----- <>-----

75th percen

4 median

3 25th percen Cubic Feet per Second

1 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 20 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) 7-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 700 <>------<>------

600

500

400 75th percen

300 median

Cubic Feet per Second 200

25th percen 100

0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 21 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) 30-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 900 <>------<>------

800

700

600

500 75th percen

400 median

300 Cubic Feet per Second

200 25th percen

100

0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 22 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) 90-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 1200 <>------<>------

1000

800

75th percen 600

median 400 Cubic Feet per Second

25th percen 200

0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 23 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) 1-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 50000 <>------<>------

40000

30000

20000

75th percen Cubic Feet per Second

10000

median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 24 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) 3-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 50000 <>------<>------

40000

30000

20000 Cubic Feet per Second 75th percen

10000

median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 25 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) 7-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 30000 <>------<>------

25000

20000

15000

10000 75th percen Cubic Feet per Second

5000 median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 26 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) 30-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 12000 <>------<>------

10000

8000

6000 75th percen

4000 Cubic Feet per Second median

2000

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 27 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 6000 <>------<>------

5000

4000 75th percen

3000

median

2000 Cubic Feet per Second

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 28 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) Zero streamflow days Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 11 <>------<>------

Number 5

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 200025th percen Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 29 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) Base Flow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 0.6 <>------<>------

0.5

0.4 75th percen

0.3

0.2 median Cubic Feet per Second

0.1 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 30 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) Date of minimum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 400 <>------<>------

75th percen

median 300 25th percen

200 Julian Day

100

0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 31 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) Date of maximum streamflow Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 400 <>------<>------

300

200 Julian Day

100 75th percen

median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 32 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) Low Pulse Count Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 50 <>------<>------

30 Number 20

10 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 200025th percen Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 33 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) Low Pulse Duration Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 50 <>------<>------

30 Days

75th percen median 0 1860 1880 1900 1920 1940 1960 1980 200025th percen Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 34 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) High Pulse Count Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 30 <>------<>------

75th percen 15 Number

median 10

5 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 35 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) High Pulse Duration Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 50 <>------<>------

30 Days

75th percen

median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 36 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) Rise Rate Pre-Impact Period Post-Impact Period 1875 1896 1975 1996 1000 <>------<>------

900

800

700

600

500 75th percen CFS/Day 400

300 median

200 25th percen

100

0 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 37 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA 4445 South Fork American River Near Placerville (Natural) Fall Rate

0 1875Pre-Impact<>------Period 1896 Post-Impact<>1975------Period 1996

-100

75th percen -200

median CFS/Day -300

25th percen -400

-500 1860 1880 1900 1920 1940 1960 1980 2000 Year

File(s) Used: P:\Framatome\IHA\8-CB-Nat\CB-Nat.ann, P:\Framatome\IHA\8-CB-Nat\CB-Nat.baw

01/08/2004 Page 38 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

Standard IHA Pre-Impact4415 South Period Fork Silver Creek below Ice House Post-Impact Reservoir Period Reversals 1886 1901 1986 2001

130 <>----- <>-----

120

110

100

75th percen

Number 90

median 80

25th percen 70

60 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.ann, P:\Framatome\IHA\3-Icehouse\Icehouse.baw

01/08/2004 Page 39 of 40 Analysis 3 - South Fork Silver Creek below Ice House Reservoir (Unregulated) versus 4415 South Fork Silver Creek below Ice House Reservoir (Regulated)

4415 South Fork Silver Creek below Ice House Reservoir

6000

5000

4000

3000

2000 Cubic Feet per Second

1000

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome\IHA\3-Icehouse\Icehouse.dat

01/08/2004 Page 40 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated)

Errors

No Errors

02/02/04 Page 1 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated)

IHA Annual Summary Statistics

Year October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

1875 47.6 84.1 103.2 184.5 261.3 490.9 458.8 1635.2 1254.8 238.3 60.9 35.7 30.6 31.0 31.0 35.7 61.4 1876 167.1 164.0 125.5 121.0 138.4 223.6 322.8 344.0 79.3 32.2 44.8 34.7 26.1 26.2 27.0 29.7 36.8 1877 36.8 39.1 38.3 70.2 91.4 97.4 215.5 265.6 131.6 19.5 5.6 7.0 3.9 4.1 4.2 5.6 7.2 1878 9.9 52.4 380.9 772.8 424.0 929.2 902.3 1288.5 974.9 259.6 69.2 75.4 8.0 8.1 8.3 9.8 60.6 1879 47.8 84.1 103.2 184.5 261.3 490.9 458.8 1635.2 1254.8 238.3 60.9 35.7 30.6 28.2 27.7 31.7 54.0 1880 70.8 177.2 192.2 2778.1 1037.5 587.4 889.7 1101.3 805.2 353.6 62.1 32.4 26.3 24.1 22.8 27.9 37.9 1881 32.4 55.3 110.7 119.2 274.5 396.8 704.0 543.8 125.1 39.9 25.1 23.1 19.5 20.0 20.3 21.7 27.7 1882 57.5 1012.4 1249.3 559.3 1745.3 1065.9 1591.6 2243.5 1215.5 288.5 91.1 169.2 27.0 31.4 35.4 55.6 118.9 1883 414.8 398.6 788.6 616.3 930.4 1714.1 935.4 1957.0 2815.4 1315.7 325.9 99.1 69.2 70.7 73.5 74.5 163.3 1884 106.0 2040.6 1862.1 767.2 530.2 711.5 667.6 1157.0 576.1 153.3 49.2 35.2 32.9 33.0 33.5 35.2 47.7 1885 64.8 376.8 198.2 164.1 232.8 344.6 1039.8 714.7 209.4 46.8 35.9 52.0 31.2 31.2 31.7 35.5 43.7 1886 58.7 126.4 317.5 708.6 3475.3 2102.7 919.8 1032.9 574.1 130.5 59.4 57.1 35.7 36.0 36.3 40.6 60.1 1887 73.6 54.7 62.5 86.1 273.4 366.9 628.3 385.4 106.6 41.6 30.2 28.4 26.9 27.4 27.7 28.3 31.4 1888 44.9 55.3 157.6 206.0 218.5 321.7 372.3 300.6 145.4 37.7 28.6 29.9 22.1 22.2 23.4 26.4 28.6 1889 27.5 144.5 126.3 107.3 207.7 1402.1 1222.9 844.5 442.9 79.7 38.1 51.8 19.9 20.2 20.7 27.4 45.4 1890 80.7 101.0 103.5 202.2 165.9 474.5 708.5 461.9 296.5 63.2 33.0 26.3 20.8 21.1 21.6 25.6 30.8 1891 33.9 39.3 43.0 49.8 84.1 480.4 560.8 791.5 429.3 98.1 42.9 32.2 25.0 25.1 25.6 29.1 37.6 1892 57.4 78.7 78.1 85.5 334.1 413.8 622.9 237.1 108.2 46.9 26.8 16.9 13.9 14.1 14.6 16.9 24.1 1893 43.6 52.6 173.0 543.7 422.7 1322.4 1274.6 1637.3 942.1 254.5 108.0 55.5 19.5 21.3 22.0 40.3 56.0 1894 56.0 59.4 109.5 116.6 158.5 405.1 505.9 480.4 120.4 41.4 28.8 29.3 22.4 23.2 24.2 25.3 27.6 1895 24.9 117.0 208.4 1227.1 686.4 1683.8 1575.8 2283.2 1765.4 823.0 227.5 95.5 16.1 17.2 20.7 24.8 69.7 1896 58.3 63.7 407.5 532.8 1502.5 1152.3 1317.6 1861.3 606.1 171.8 87.1 60.3 53.2 54.1 51.8 54.4 60.9 1897 63.2 432.6 1550.7 4007.2 791.0 745.5 868.4 789.9 403.9 137.0 67.1 59.7 45.0 45.7 46.0 55.0 60.7 1898 63.2 106.5 145.4 822.7 751.2 1231.3 1113.0 1482.6 2203.5 719.1 134.4 89.4 41.0 42.6 45.8 62.5 84.6 1899 72.3 197.6 280.8 673.6 1175.8 854.2 949.1 1585.9 933.1 192.2 93.4 62.3 57.4 41.7 36.7 40.0 60.3 1900 48.8 91.2 85.4 551.8 815.8 710.9 972.6 1109.2 327.4 91.4 51.1 45.5 32.2 32.1 29.4 38.2 46.2 1901 47.3 89.4 118.8 95.0 132.2 471.1 598.1 591.3 80.7 43.0 33.2 27.8 25.6 24.4 23.6 23.2 15.4 1975 23.1 11.9 10.0 13.3 24.2 33.8 28.9 24.9 21.5 20.9 19.8 22.0 9.4 9.5 9.7 9.9 11.2 1976 22.6 10.9 10.6 11.0 12.5 11.0 10.2 5.6 5.6 5.3 5.5 5.4 3.9 3.9 4.3 5.3 5.4 1977 5.6 5.8 5.4 5.2 5.5 3.6 3.1 3.3 3.3 3.0 3.1 3.2 2.0 2.0 2.7 3.0 3.1 1978 3.1 3.4 9.6 26.5 17.1 25.2 26.7 17.0 16.9 23.3 20.6 20.1 2.9 3.0 3.0 3.1 4.9 1979 23.0 11.9 10.0 13.3 24.2 33.8 28.9 24.9 21.5 20.9 19.8 22.0 9.4 9.5 9.7 9.9 11.2 1980 15.9 9.6 10.7 634.8 47.2 24.7 13.8 20.3 19.3 19.0 19.0 19.0 7.3 7.5 7.9 9.0 11.6 1981 19.3 10.0 9.8 11.4 15.6 20.6 11.2 10.0 9.6 10.1 10.3 9.9 1.0 4.8 8.1 9.6 9.6 1982 10.0 24.0 111.2 31.8 552.6 94.3 514.8 991.2 609.8 20.0 21.5 20.8 4.4 5.6 5.9 8.9 20.1 1983 23.4 19.8 69.6 25.3 147.7 824.7 751.7 605.7 919.6 411.6 20.6 19.8 9.6 9.9 10.0 18.0 20.0 1984 20.2 1088.1 729.6 205.6 20.7 23.8 16.1 17.8 19.6 24.6 24.7 21.3 3.8 10.3 10.7 14.2 17.6 1985 21.7 18.2 14.6 15.5 20.7 22.5 21.9 17.0 15.3 16.7 16.9 17.5 9.3 9.7 10.7 14.2 14.5 1986 18.2 10.6 14.5 19.1 1168.0 1206.5 49.3 24.4 20.3 21.1 21.9 22.2 7.6 8.2 8.5 10.5 14.1 1987 22.0 11.3 11.8 12.7 17.7 20.1 12.3 11.8 11.5 10.7 10.7 11.0 9.6 10.0 10.1 10.5 8.5 1988 11.0 6.9 7.4 10.0 6.8 6.6 6.7 5.5 5.2 5.5 6.1 6.5 5.1 5.1 5.1 5.2 5.4 1989 6.0 7.1 5.5 6.2 11.0 41.5 12.5 20.7 22.5 22.6 23.5 23.6 5.1 5.2 5.3 5.5 6.1 1990 22.0 12.0 11.4 11.6 27.7 18.0 10.7 10.7 11.0 11.0 11.2 11.0 10.0 10.0 10.0 10.3 8.3 1991 11.1 6.9 6.6 6.5 67.9 12.9 17.8 11.0 11.3 11.9 11.2 11.1 5.8 6.0 6.1 6.3 6.6 1992 10.9 6.9 6.8 6.8 16.1 12.9 6.9 11.1 11.0 11.0 11.0 11.0 6.4 6.5 6.5 6.7 6.8 1993 12.0 6.9 8.7 63.0 24.4 39.4 19.9 23.6 21.7 20.6 20.5 21.0 6.4 6.4 6.6 6.7 8.9 1994 21.3 11.4 10.8 11.0 11.4 12.8 11.0 6.3 5.5 5.4 5.5 5.4 5.3 5.3 5.3 5.4 5.5 1995 137.8 52.7 9.7 154.1 14.8 104.0 402.4 1504.7 1019.4 503.3 23.7 23.8 5.3 5.3 5.4 8.5 15.9 1996 23.9 11.3 11.7 22.6 74.7 226.6 87.7 979.3 54.3 28.1 27.9 28.3 11.0 11.0 11.0 11.0 13.6 1997 30.2 12.0 436.0 4121.7 510.8 163.0 13.8 23.6 97.3 22.9 22.6 23.1 10.0 10.0 10.3 11.9 17.0 1998 24.0 14.8 11.5 42.8 45.6 63.8 23.2 23.1 961.6 187.0 31.6 28.8 11.0 11.0 11.0 11.0 15.5 1999 27.7 25.1 20.2 41.8 423.3 320.4 51.8 36.7 28.2 27.1 27.1 28.7 19.0 19.0 19.4 19.9 14.7 2000 20.6 11.4 11.2 24.8 44.7 22.1 13.8 22.9 22.5 24.3 22.9 23.0 7.3 7.9 8.6 10.5 11.3 2001 20.2 13.8 13.5 13.7 13.8 14.7 20.7 13.9 14.0 13.9 14.0 13.5 6.7 8.3 12.1 13.2 13.6

02/02/04 Page 2 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated)

IHA Annual Summary Statistics (Cont)

Year 1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

1875 2669.5 2431.1 2314.8 2011.8 1147.2 0.0 0.1 271.0 152.0 3.0 25.0 3.0 23.3 64.5 -38.9 113.0 1876 1537.8 751.9 505.3 446.9 303.6 0.0 0.2 211.0 300.0 5.0 19.8 1.0 1.0 29.4 -15.4 126.0 1877 445.1 411.9 376.8 289.4 213.8 0.0 0.1 228.0 148.0 7.0 24.0 0.0 0.0 10.0 -7.9 112.0 1878 2505.1 1919.2 1552.6 1370.9 1124.0 0.0 0.0 278.0 17.0 3.0 12.0 10.0 14.1 114.2 -65.2 112.0 1879 2669.5 2431.1 2314.8 2011.8 1147.2 0.0 0.1 271.0 152.0 3.0 16.0 3.0 23.3 64.5 -38.7 114.0 1880 24024.1 17237.8 9879.4 2900.0 1504.0 0.0 0.0 275.0 13.0 3.0 17.0 6.0 21.7 294.5 -142.5 87.0 1881 1411.8 1308.1 1164.1 797.3 737.6 0.0 0.1 264.0 115.0 4.0 28.5 4.0 7.0 45.1 -20.7 105.0 1882 12008.8 7906.3 4769.2 2261.7 1721.3 0.0 0.0 276.0 47.0 3.0 7.7 7.0 24.6 408.0 -168.4 102.0 1883 10551.7 6059.6 3830.0 3223.1 2087.7 0.0 0.1 279.0 73.0 0.0 0.0 7.0 30.1 262.0 -135.7 109.0 1884 9581.7 6583.1 4796.4 2149.5 1583.3 0.0 0.1 268.0 322.0 1.0 55.0 9.0 17.7 275.0 -133.3 112.0 1885 1837.9 1725.5 1529.9 1104.7 707.9 0.0 0.1 240.0 106.0 4.0 22.8 3.0 19.0 38.0 -25.8 116.0 1886 17632.5 15706.4 9722.2 4531.8 2161.6 0.0 0.1 256.0 48.0 2.0 19.5 6.0 24.0 346.4 -166.1 97.0 1887 2251.1 1172.5 798.4 670.0 484.7 0.0 0.2 274.0 44.0 6.0 22.7 5.0 5.6 31.9 -21.8 120.0 1888 1018.6 499.6 426.8 378.8 338.0 0.0 0.2 251.0 5.0 6.0 20.7 2.0 1.0 25.1 -18.5 121.0 1889 4001.3 3179.8 2571.7 1556.2 1174.4 0.0 0.1 276.0 68.0 7.0 10.6 5.0 17.2 84.6 -52.6 122.0 1890 1081.6 891.3 789.9 709.2 565.0 0.0 0.1 256.0 114.0 3.0 24.7 7.0 6.3 35.2 -19.9 113.0 1891 5103.5 2614.1 1418.2 837.8 621.4 0.0 0.1 279.0 64.0 2.0 34.0 7.0 7.6 59.0 -39.4 112.0 1892 1137.5 1027.8 785.6 624.8 494.1 0.0 0.1 273.0 108.0 4.0 25.3 5.0 3.8 29.6 -15.5 123.0 1893 4253.6 3298.4 2464.3 1669.9 1529.6 0.0 0.0 275.0 77.0 4.0 13.3 5.0 23.6 144.5 -64.4 103.0 1894 912.0 874.6 788.5 616.5 473.1 0.0 0.1 254.0 110.0 4.0 32.5 3.0 5.7 24.3 -15.1 128.0 1895 8831.9 7156.0 5289.8 2468.3 1971.4 0.0 0.0 276.0 122.0 2.0 2.0 7.0 26.1 255.2 -147.0 96.0 1896 6131.6 5826.7 3864.4 2024.5 1460.7 0.0 0.1 282.0 36.0 9.0 4.4 6.0 24.3 250.7 -95.9 95.0 1897 32435.2 24443.4 13791.9 4474.7 2196.6 0.0 0.1 283.0 2.0 7.0 6.7 8.0 18.0 459.6 -221.3 101.0 1898 7818.4 4963.8 3370.9 2203.5 1689.6 0.0 0.1 279.0 84.0 3.0 2.7 4.0 38.8 167.4 -95.4 113.0 1899 4223.5 3070.1 2504.7 1656.6 1175.5 0.0 0.1 274.0 40.0 2.0 3.5 6.0 23.0 153.5 -77.5 106.0 1900 4493.7 2698.3 1701.2 1153.4 955.4 0.0 0.1 279.0 45.0 9.0 8.4 5.0 21.4 117.4 -66.5 119.0 1901 1296.1 1215.3 1088.0 832.4 562.4 0.0 0.1 281.0 85.0 2.0 51.0 3.0 14.0 28.6 -15.6 119.0 1975 121.0 85.0 57.1 34.4 30.7 0.0 0.5 314.0 84.0 3.0 70.7 0.0 0.0 4.5 -2.6 65.0 1976 27.0 25.3 24.1 22.7 14.8 0.0 0.4 132.0 300.0 2.0 0.5 0.0 0.0 0.7 -0.6 92.0 1977 8.7 7.1 6.4 5.8 5.6 0.0 0.6 67.0 315.0 2.0 107.0 0.0 0.0 0.3 -0.2 109.0 1978 103.0 76.3 56.7 29.6 23.8 0.0 0.2 283.0 17.0 4.0 62.8 0.0 0.0 5.7 -3.3 68.0 1979 121.0 85.0 57.1 34.4 30.7 0.0 0.5 314.0 84.0 3.0 70.7 0.0 0.0 4.5 -2.6 65.0 1980 5280.0 3710.0 2487.9 656.4 242.6 0.0 0.1 338.0 13.0 3.0 82.0 1.0 9.0 94.0 -46.6 66.0 1981 66.0 55.0 40.6 21.1 46.9 0.0 0.7 306.0 86.0 3.0 70.7 0.0 0.0 1.8 -1.5 99.0 1982 5010.0 3203.3 1756.0 991.5 717.1 0.0 0.0 309.0 47.0 9.0 21.1 7.0 8.3 138.3 -91.3 105.0 1983 3800.0 2143.3 1451.4 1185.8 806.6 0.0 0.0 346.0 73.0 8.0 18.3 9.0 10.1 107.0 -70.5 110.0 1984 4470.0 3566.7 2630.0 1194.9 685.2 0.0 0.1 195.0 322.0 6.0 48.0 4.0 7.0 143.5 -87.8 99.0 1985 43.0 36.3 34.0 26.5 21.8 0.0 0.6 344.0 333.0 2.0 107.0 0.0 0.0 2.3 -1.9 95.0 1986 9810.0 7253.3 4095.7 2071.0 797.1 0.0 0.0 317.0 48.0 5.0 40.2 4.0 6.5 186.7 -128.2 102.0 1987 53.0 36.3 27.4 22.0 16.9 0.0 0.7 365.0 44.0 2.0 107.0 0.0 0.0 2.4 -1.8 61.0 1988 19.0 15.7 13.8 11.0 8.6 0.0 0.7 144.0 11.0 2.0 0.5 0.0 0.0 0.5 -0.4 135.0 1989 99.0 66.0 53.9 42.3 25.2 0.0 0.3 309.0 68.0 4.0 53.0 0.0 0.0 2.9 -2.4 125.0 1990 130.0 86.7 72.0 31.6 18.8 0.0 0.7 112.0 52.0 4.0 55.3 0.0 0.0 6.3 -4.6 47.0 1991 477.0 439.0 251.0 68.2 32.4 0.0 0.4 15.0 52.0 2.0 109.0 0.0 0.0 7.9 -5.8 93.0 1992 53.0 44.3 33.1 19.2 12.4 0.0 0.6 98.0 51.0 2.0 0.5 0.0 0.0 1.3 -0.9 92.0 1993 818.0 444.3 214.1 68.5 45.2 0.0 0.3 351.0 22.0 4.0 61.8 1.0 1.0 13.3 -9.6 86.0 1994 24.0 23.3 22.6 112.8 68.1 0.0 0.5 176.0 289.0 2.0 107.0 0.0 0.0 0.5 -0.6 98.0 1995 7280.0 5623.3 3334.3 1506.2 1122.4 0.0 0.0 279.0 123.0 8.0 26.1 9.0 8.2 150.4 -110.2 117.0 1996 6170.0 5660.0 3409.4 1021.9 447.9 0.0 0.1 308.0 137.0 12.0 13.2 4.0 3.3 124.7 -85.1 114.0 1997 32900.0 22333.3 13677.1 4308.9 1763.5 0.0 0.0 307.0 2.0 6.0 34.0 7.0 6.4 584.9 -346.3 103.0 1998 2380.0 2256.7 1901.1 1112.1 395.8 0.0 0.1 321.0 169.0 8.0 26.5 2.0 11.0 68.1 -48.9 99.0 1999 1850.0 998.3 795.6 598.4 264.0 0.0 0.2 329.0 40.0 8.0 30.9 3.0 6.7 49.0 -37.8 122.0 2000 323.0 183.3 108.1 49.2 30.9 0.0 0.4 298.0 45.0 4.0 60.5 0.0 0.0 10.2 -6.9 77.0 2001 57.0 56.3 43.4 20.9 16.4 0.0 0.8 301.0 111.0 2.0 107.0 0.0 0.0 2.5 -2.2 85.0

02/02/04 Page 3 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated)

Non-Parametric IHA Scorecard

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Watershed area 1.00 Mean annual flow 450.03 89.48 Mean flow/area 450.03 89.48 Annual C. V. .94 .08 Flow predictability .41 .42 Constancy/predictability .44 .79 % of floods in 60d period .41 .41 flood-free season 53.00 125.00

MEDIANS COEFF. of DISP. DEVIATION FACTOR SIGNIFICANCE COUNT Pre Post Pre Post Medians C.V. Medians C.V. Parameter Group #1 October 57.4 20.6 .47 .58 .64 .24 .06 .51 November 91.2 11.4 1.34 .67 .88 .50 .20 .44 December 145.4 10.8 1.47 .45 .93 .69 .25 .38 January 206.0 15.5 2.87 1.99 .92 .31 .15 .64 February 334.1 24.2 1.82 2.19 .93 .20 .15 .71 March 587.4 24.7 1.27 3.22 .96 1.53 .18 .15 April 868.4 17.8 .55 .99 .98 .80 .26 .41 May 1032.9 20.3 1.12 .69 .98 .39 .22 .60 June 442.9 19.6 1.90 .88 .96 .54 .13 .33 July 130.5 20.6 1.62 .65 .84 .60 .05 .22 August 51.1 19.8 1.06 .60 .61 .43 .00 .34 September 35.7 20.1 .87 .60 .44 .32 .00 .69

Parameter Group #2 1-day minimum 26.3 6.7 .49 .67 .75 .36 .16 .51 3-day minimum 26.2 7.9 .45 .60 .70 .32 .20 .57 7-day minimum 27.0 8.5 .51 .58 .69 .14 .25 .85 30-day minimum 29.7 9.9 .50 .48 .67 .06 .17 .91 90-day minimum 46.2 11.2 .65 .72 .76 .11 .12 .77 1-day maximum 4001.3 130.0 1.85 33.98 .97 17.32 .14 .00 3-day maximum 2614.1 86.7 1.87 36.45 .97 18.50 .17 .00 7-day maximum 2314.8 72.0 1.32 25.93 .97 18.58 .10 .00 30-day maximum 1556.2 49.2 .96 20.32 .97 20.16 .02 .00 90-day maximum 1147.2 32.4 .89 13.24 .97 13.88 .04 .00 Number of zero days .0 .0 .00 .00 999999.00 999999.00 .00 .00 Base flow .1 .4 .88 1.42 4.47 .61 .00 .29

Parameter Group #3 Date of minimum 274.0 309.0 .06 .16 .19 1.57 .00 .01 Date of maximum 68.0 47.0 .20 .20 .11 .01 .21 .97

Parameter Group #4 Low pulse count 3.0 4.0 1.33 1.00 .33 .25 .01 .56 Low pulse duration 19.5 55.3 .89 1.01 1.83 .14 .00 .65 High pulse count 5.0 .0 .80 .00 1.00 1.00 .03 .05 High pulse duration 18.0 .0 .96 .00 1.00 1.00 .04 .05 The low pulse threshold is 60.38 The high pulse level is 580.89

Parameter Group #5 Rise rate 84.6 6.3 2.64 16.66 .93 5.31 .17 .00 Fall rate -52.6 -4.6 -2.16 -15.04 .91 5.98 .22 .00 Number of reversals 112.0 98.0 .14 .33 .13 1.29 .01 .00

02/02/04 Page 4 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated)

Variance Data, Box and Whisker Format

October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

Pre-Impact Distribution 1-day min 9.9 39.1 38.3 49.8 84.1 97.4 215.5 237.1 79.3 19.5 5.6 7.0 3.9 4.1 4.2 5.6 7.2 25 pctile 43.6 55.3 103.2 116.6 207.7 405.1 560.8 480.4 131.6 43.0 33.0 29.3 19.9 21.1 21.6 25.3 30.8 Median 57.4 91.2 145.4 206.0 334.1 587.4 868.4 1032.9 442.9 130.5 51.1 35.7 26.3 26.2 27.0 29.7 46.2 75 pctile 70.8 177.2 317.5 708.6 815.8 1152.3 1039.8 1635.2 974.9 254.5 87.1 60.3 32.9 33.0 35.4 40.3 60.7 1-day max 414.8 2040.6 1862.1 4007.2 3475.3 2102.7 1591.6 2283.2 2815.4 1315.7 325.9 169.2 69.2 70.7 73.5 74.5 163.3

Post-Impact Distribution 1-day min 3.1 3.4 5.4 5.2 5.5 3.6 3.1 3.3 3.3 3.0 3.1 3.2 1.0 2.0 2.7 3.0 3.1 25 pctile 11.1 7.1 9.6 11.0 14.8 14.7 11.2 11.0 11.0 11.0 11.0 11.0 5.1 5.3 5.4 6.3 6.6 Median 20.6 11.4 10.8 15.5 24.2 24.7 17.8 20.3 19.6 20.6 19.8 20.1 6.7 7.9 8.5 9.9 11.2 75 pctile 23.1 14.8 14.5 41.8 67.9 94.3 28.9 24.9 28.2 24.3 22.9 23.0 9.6 10.0 10.3 11.0 14.7 1-day max 137.8 1088.1 729.6 4121.7 1168.0 1206.5 751.7 1504.7 1019.4 503.3 31.6 28.8 19.0 19.0 19.4 19.9 20.1

1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

Pre-Impact Distribution 1-day min 445.1 411.9 376.8 289.4 213.8 0.0 0.0 211.0 2.0 0.0 0.0 0.0 0.0 10.0 -221.3 87.0 25 pctile 1411.8 1172.5 798.4 709.2 562.4 0.0 0.1 256.0 36.0 2.0 7.7 3.0 6.3 31.9 -133.3 103.0 Median 4001.3 2614.1 2314.8 1556.2 1147.2 0.0 0.1 274.0 68.0 3.0 19.5 5.0 18.0 84.6 -52.6 112.0 75 pctile 8831.9 6059.6 3864.4 2203.5 1583.3 0.0 0.1 279.0 110.0 6.0 25.0 7.0 23.6 255.2 -19.9 119.0 1-day max 32435.2 24443.4 13791.9 4531.8 2196.6 0.0 0.2 283.0 322.0 9.0 55.0 10.0 38.8 459.6 -7.9 128.0

Post-Impact Distribution 1-day min 8.7 7.1 6.4 5.8 5.6 0.0 0.0 15.0 2.0 2.0 0.5 0.0 0.0 0.3 -346.3 47.0 25 pctile 53.0 44.3 34.0 22.7 18.8 0.0 0.1 279.0 11.0 2.0 26.1 0.0 0.0 2.3 -70.5 77.0 Median 130.0 86.7 72.0 49.2 32.4 0.0 0.4 309.0 47.0 4.0 55.3 0.0 0.0 6.3 -4.6 98.0 75 pctile 4470.0 3203.3 1901.1 1021.9 447.9 0.0 0.6 338.0 84.0 6.0 82.0 4.0 6.7 107.0 -1.8 109.0 1-day max 32900.0 22333.3 13677.1 4308.9 1763.5 0.0 0.8 365.0 333.0 12.0 109.0 9.0 11.0 584.9 -0.2 135.0

02/02/04 Page 5 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated)

IHA Percentile Data

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Pre-Impact Post-Impact 10% 25% 50% 75% 90% (75-25)/50 10% 25% 50% 75% 90% (75-25)/50

Parameter Group #1 October 27.01 43.63 57.36 70.77 118.21 .47 5.92 11.06 20.58 23.10 28.20 .58 November 49.76 55.27 91.23 177.22 548.60 1.34 6.64 7.14 11.40 14.77 30.65 .67 December 58.61 103.24 145.44 317.54 1309.61 1.47 6.38 9.61 10.81 14.49 176.12 .45 January 82.43 116.59 206.01 708.60 1537.27 2.87 6.46 11.00 15.48 41.81 291.40 1.99 February 124.03 207.67 334.09 815.80 1551.04 1.82 10.20 14.82 24.18 67.85 519.15 2.19 March 302.03 405.09 587.37 1152.30 1689.89 1.27 10.15 14.65 24.74 94.32 421.28 3.22 April 362.39 560.82 868.39 1039.84 1369.27 .55 6.84 11.23 17.77 28.87 424.89 .99 May 293.60 480.43 1032.94 1635.15 2014.30 1.12 5.59 11.00 20.29 24.94 981.70 .69 June 101.40 131.56 442.90 974.90 1853.05 1.90 5.41 11.00 19.60 28.23 928.00 .88 July 36.62 43.04 130.46 254.52 739.86 1.62 5.41 11.00 20.58 24.32 231.90 .65 August 26.46 33.02 51.08 87.10 153.02 1.06 5.50 11.00 19.77 22.94 27.23 .60 September 21.88 29.27 35.70 60.32 96.20 .87 5.43 11.00 20.10 22.97 28.35 .60

Parameter Group #2 1-day minimum 12.73 19.90 26.33 32.90 54.03 .49 2.72 5.10 6.70 9.60 11.00 .67 3-day minimum 12.91 21.14 26.18 33.02 47.34 .45 3.74 5.30 7.87 10.00 11.00 .60 7-day minimum 13.35 21.61 26.98 35.39 47.14 .51 4.03 5.36 8.47 10.29 11.21 .58 30-day minimum 15.45 25.28 29.74 40.29 56.98 .50 4.77 6.32 9.91 11.03 14.98 .48 90-day minimum 22.33 30.76 46.20 60.69 91.41 .65 5.28 6.60 11.20 14.69 18.10 .72 1-day maximum 997.28 1411.75 4001.28 8831.91 18910.81 1.85 23.00 53.00 130.00 4470.00 7786.00 33.98 3-day maximum 701.41 1172.48 2614.10 6059.56 16012.68 1.87 21.80 44.33 86.67 3203.33 5978.67 36.45 7-day maximum 489.58 798.42 2314.82 3864.35 9753.63 1.32 20.81 34.00 72.00 1901.14 3546.68 25.93 30-day maximum 433.25 709.24 1556.21 2203.49 3473.44 .96 17.53 22.73 49.17 1021.90 1619.13 20.32 90-day maximum 331.13 562.38 1147.20 1583.30 2102.47 .89 11.66 18.81 32.41 447.92 869.77 13.24 Number of zero days .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 Base flow .03 .05 .07 .11 .15 .88 .02 .08 .39 .64 .73 1.42

Parameter Group #3 Date of minimum 237.60 256.00 274.00 279.00 281.20 .06 128.00 279.00 309.00 338.00 2.20 .16 Date of maximum 358.80 36.00 68.00 110.00 148.80 .20 312.00 11.00 47.00 84.00 125.80 .20

Parameter Group #4 Low pulse count 1.80 2.00 3.00 6.00 7.40 1.33 2.00 2.00 4.00 6.00 8.20 1.00 Low pulse duration 2.53 7.67 19.50 25.00 37.40 .89 .50 26.13 55.25 82.00 107.00 1.01 High pulse count 1.80 3.00 5.00 7.00 8.20 .80 .00 .00 .00 4.00 7.40 .00 High pulse duration 1.00 6.29 18.00 23.60 26.94 .96 .00 .00 .00 6.67 9.22 .00

Parameter Group #5 Rise rate 24.95 31.90 84.59 255.19 358.69 2.64 .49 2.29 6.29 106.99 157.68 16.66 Fall rate -166.59 -133.29 -52.63 -19.86 -15.30 -2.16 -113.79 -70.53 -4.57 -1.81 -.55 -15.04 Number of reversals 95.80 103.00 112.00 119.00 123.60 .14 64.20 77.00 98.00 109.00 122.60 .33

02/02/04 Page 6 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Average flow for October Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 500 <>------<------>

400

300

200 Cubic Feet per Second

100

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 7 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek belowAverage Camino flow forDiversion November Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 2500 <>------<------>

2000

1500

1000 Cubic Feet per Second

500

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 8 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek belowAverage Camino flow forDiversion December Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 2000 <>------<------>

1500

1000 Cubic Feet per Second 500

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 9 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below AverageCamino flow Diversionfor January Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 5000 <>------<------>

4000

3000

2000 Cubic Feet per Second

1000

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 10 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek belowAverage Camino flow forDiversion February Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000 Cubic Feet per Second 1000

75th percen median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 11 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below AverageCamino flow Diversion for March Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 2500 <>------<------>

2000

1500

1000 Cubic Feet per Second

500

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 12 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below AverageCamino flow Diversion for April Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 2000 <>------<------>

1500

1000 Cubic Feet per Second 500

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 13 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below CaminoAverage flow Diversion for May Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 2500 <>------<------>

2000

1500

1000 Cubic Feet per Second

500

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 14 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Average flow for June Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 3000 <>------<------>

2500

2000

1500

1000 Cubic Feet per Second

500

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 15 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below CaminoAverage flow Diversion for July Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1400 <>------<------>

1200

1000

800

600

Cubic Feet per Second 400

200

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 16 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below AverageCamino flow Diversionfor August Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Cubic Feet per Second 100

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 17 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Average flow for September Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 200 <>------<------>

150

100 Cubic Feet per Second 50

75th percen median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 18 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) 1-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 70 <>------<------>

Cubic Feet per Second 20

75th percen 10 median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 19 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) 3-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 80 <>------<------>

30 Cubic Feet per Second 20

75th percen 10 median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 20 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) 7-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 80 <>------<------>

30 Cubic Feet per Second 20

75th percen 10 median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 21 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) 30-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 80 <>------<------>

30 Cubic Feet per Second 20

75th percen 10 median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 22 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) 90-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 200 <>------<------>

150

100 Cubic Feet per Second 50

75th percen median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 23 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) 1-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40000 <>------<------>

30000

20000 Cubic Feet per Second 10000

75th percen

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 24 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) 3-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 25000 <>------<------>

20000

15000

10000 Cubic Feet per Second

5000 75th percen

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 25 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below 7-dayCamino maximum Diversion streamflow Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 14000 <>------<------>

12000

10000

8000

6000

Cubic Feet per Second 4000

2000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 26 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below30-day Camino maximum Diversion streamflow Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 5000 <>------<------>

4000

3000

2000 Cubic Feet per Second

75th percen 1000

median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 27 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 2500 <>------<------>

2000

1500

1000 Cubic Feet per Second

500 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 28 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Zero streamflow days Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 29 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Base Flow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 0.9 <>------<------>

0.8

0.7 75th percen

0.6

0.5

0.4 median

0.3 Cubic Feet per Second

0.2

0.1 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 30 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Date of minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

75th percen

median 300

25th percen

200 Julian Day

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 31 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Date of maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Julian Day

100 75th percen

median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 32 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Low Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 14 <>------<------>

Number 75th percen 6

4 median

2 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 33 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Low Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 120 <>------<------>

100

75th percen 80

Days median

25th percen 20

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 34 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) High Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 4

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 35 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below CaminoHigh Pulse DiversionDuration Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 Days

10 75th percen

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 36 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA

4419 Silver Creek below CaminoRise RateDiversion Dam (Jan04 Analysis) Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 600 <>------<------>

500

400

300 CFS/Day

200

75th percen 100

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 37 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Fall Rate

75th percen 0 median 1875Pre-Impact<>------Period 1901 Post-Impact < 1975------Period 2001 >

25th percen -100

-200 CFS/Day

-300

-400 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 38 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated) Standard IHA 4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis) Pre-Impact PeriodReversals Post-Impact Period

1875 1901 1975 2001 140 <>------<------>

130

120

110 75th percen

100 median

90 Number 80 25th percen 70

40 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.ann, C:\Documents and Settings\Admin

02/02/04 Page 39 of 40 Analysis 4 - Silver Creek below Camino Diversion Dam (Unregulated) versus 4419 Silver Creek below Camino Diversion Dam (Regulated)

4419 Silver Creek below Camino Diversion Dam (Jan04 Analysis)

40000

30000

20000 Cubic Feet per Second 10000

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: C:\Documents and Settings\Administrator\Desktop\IHA\IHA Jan04 B\1-Camino\cam.dat

02/02/04 Page 40 of 40 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Errors

No Errors

04/21/04 Page 1 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

IHA Annual Summary Statistics

Year October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

1875 171.7 227.0 245.7 368.8 563.1 1028.1 988.5 3864.3 3266.5 695.2 226.1 218.0 113.0 114.2 120.8 169.5 215.5 1876 394.2 427.2 364.6 266.6 294.4 440.5 628.3 771.9 189.6 96.6 97.2 94.4 54.3 55.3 57.0 68.6 91.2 1877 99.0 108.6 73.4 128.3 154.8 166.3 398.8 497.5 317.6 73.4 25.9 40.6 23.4 23.5 24.0 25.8 35.5 1878 41.6 126.3 639.9 1433.4 905.8 1978.0 2150.9 3155.4 2593.9 690.0 222.3 297.0 26.6 27.0 27.8 41.3 217.7 1879 175.1 227.0 245.7 368.8 563.1 1028.1 988.5 3864.3 3266.5 695.2 226.1 218.0 113.0 114.2 111.6 154.3 215.5 1880 224.5 384.6 378.9 4824.3 2700.7 1364.0 2039.6 2948.2 2209.6 961.4 253.5 212.2 94.2 94.5 94.8 139.5 170.4 1881 135.9 170.3 230.5 256.1 541.1 746.5 1437.0 1331.4 387.4 147.4 52.9 100.7 44.8 46.5 48.6 52.7 90.3 1882 167.9 1712.0 2384.9 1200.7 4060.6 2366.3 4003.7 5115.4 2808.6 891.9 303.5 449.8 61.8 68.8 89.1 164.7 368.1 1883 958.7 968.0 1753.3 1363.5 2403.2 4080.3 2321.3 4917.4 6576.2 2984.0 727.7 406.3 210.1 213.5 222.6 384.6 500.0 1884 455.3 3521.0 4030.3 1765.4 1218.1 1641.9 1535.2 3074.5 1639.8 454.6 189.9 187.0 127.6 128.4 128.9 144.3 195.8 1885 230.7 719.3 472.7 350.9 473.1 659.3 2169.1 1646.0 509.7 168.1 99.7 193.9 64.7 65.0 66.8 89.0 141.0 1886 164.9 289.7 589.3 1285.2 7620.4 4167.2 2191.8 2785.3 1738.9 409.6 211.9 238.8 89.1 90.8 101.8 165.4 167.0 1887 212.4 156.3 123.3 168.0 481.2 671.1 1126.5 832.5 224.6 120.6 54.3 90.1 53.2 53.3 53.4 54.1 72.7 1888 102.9 140.4 274.8 387.1 377.4 586.1 692.5 652.3 325.8 131.0 51.5 75.3 47.1 47.8 48.5 51.4 65.7 1889 70.7 274.3 211.9 199.8 386.0 2795.4 2589.7 1924.2 1081.4 244.5 150.9 192.3 43.9 44.4 45.9 70.9 155.7 1890 219.7 284.7 205.1 376.0 340.4 910.3 1404.2 964.1 610.5 178.2 83.0 128.2 58.3 59.7 60.4 69.8 96.2 1891 92.9 110.3 84.3 91.9 146.5 886.8 1091.9 1619.9 1040.2 248.0 112.2 140.0 52.8 53.7 55.1 76.8 91.7 1892 145.9 218.1 151.8 162.8 657.4 764.5 1173.3 553.9 197.1 135.8 52.5 97.1 49.2 49.6 50.0 52.4 72.3 1893 112.5 141.6 380.6 1243.1 1018.7 2737.0 2726.9 3874.6 2381.7 661.3 260.3 221.5 46.0 46.5 46.9 105.6 179.8 1894 168.9 175.7 215.0 217.4 305.9 699.9 916.3 949.8 296.4 139.0 53.6 80.3 50.4 51.3 52.2 53.6 72.4 1895 84.3 252.6 402.9 2528.0 1349.7 3908.6 3306.2 5176.2 4691.3 2568.1 559.6 319.0 46.8 54.1 56.8 84.2 245.7 1896 267.7 229.2 776.1 1051.0 3145.5 2367.9 2802.4 4344.5 1758.9 502.4 209.7 220.0 142.8 143.7 144.3 179.3 197.2 1897 182.5 809.5 3182.4 8147.1 1731.0 1753.6 2155.1 2657.8 1279.4 338.1 172.5 158.6 124.3 125.0 124.3 139.6 162.4 1898 166.7 255.7 278.6 1522.3 1789.8 2574.3 2473.0 3536.7 5552.4 2244.1 389.9 327.2 106.7 109.0 113.8 166.7 232.9 1899 252.6 470.4 573.4 1284.4 2445.8 1703.8 2104.9 3970.5 2779.0 599.2 256.8 227.3 159.9 162.4 149.0 164.7 202.2 1900 176.4 239.9 187.4 1056.4 1883.3 1552.6 2285.3 2906.2 1068.2 283.9 147.2 154.4 115.8 115.9 108.5 134.8 147.1 1901 149.8 206.5 221.7 208.1 320.2 879.1 1178.5 1589.8 258.5 146.6 61.8 95.0 57.9 58.3 47.2 40.2 27.3 1975 38.2 21.6 18.8 18.3 19.4 63.4 68.4 67.4 83.6 36.9 36.0 36.4 17.0 17.0 17.0 18.0 18.8 1976 36.1 19.5 19.3 19.7 18.7 15.7 24.9 24.4 26.4 24.9 23.5 24.3 15.0 15.0 15.4 15.7 18.0 1977 24.7 15.8 15.0 16.0 15.5 11.4 10.9 9.7 10.0 9.9 10.4 10.1 7.1 8.0 8.6 9.6 9.8 1978 10.0 10.3 10.7 10.3 14.3 21.7 75.1 74.8 78.5 36.6 35.0 35.1 9.2 9.4 9.5 10.0 10.3 1979 38.1 21.6 18.8 18.3 19.4 63.4 68.4 67.4 83.6 36.9 36.0 36.4 17.0 17.0 17.0 18.0 18.8 1980 29.8 16.4 16.3 1563.5 342.4 28.3 71.6 83.9 79.8 28.6 45.1 48.2 11.0 12.3 13.0 16.1 19.0 1981 37.5 21.3 21.0 20.5 20.9 13.8 24.7 25.7 19.0 19.0 19.0 19.0 12.0 12.0 12.3 13.6 16.3 1982 19.0 15.3 423.1 12.0 1189.5 26.6 1164.5 1415.0 77.3 38.6 39.0 39.0 5.8 5.8 9.8 11.0 38.2 1983 47.5 41.4 336.9 117.4 524.1 666.1 49.0 1243.9 2577.0 526.5 41.0 42.0 17.0 17.7 18.4 37.9 39.6 1984 38.2 917.6 1111.5 112.9 37.5 38.2 37.8 38.5 38.0 39.1 38.6 39.1 33.0 35.0 36.9 37.1 37.7 1985 38.7 40.0 37.5 37.0 38.0 38.0 38.5 38.9 37.3 38.1 37.5 37.2 36.0 36.0 36.3 37.0 37.2 1986 37.2 41.8 36.9 39.1 2709.3 1089.7 51.2 37.4 39.3 39.2 38.6 37.3 26.0 32.0 33.1 36.8 37.1 1987 37.3 37.3 37.0 37.2 37.1 12.7 12.2 11.7 36.8 36.0 36.0 36.0 11.0 11.0 11.0 11.3 11.8 1988 36.0 23.6 10.0 10.0 10.0 14.2 10.0 10.4 36.0 36.6 36.5 36.3 10.0 10.0 10.0 10.0 10.0 1989 36.0 23.3 10.0 10.3 10.6 17.6 33.6 37.8 36.0 36.0 36.0 36.0 10.0 10.0 10.0 10.0 10.3 1990 36.1 36.0 36.0 36.0 86.4 31.3 12.2 10.4 36.0 36.0 36.0 36.0 10.0 10.0 10.0 10.0 17.6 1991 36.0 23.4 10.0 10.1 10.2 20.9 10.7 10.7 37.3 36.8 36.8 37.1 10.0 10.0 10.0 10.0 10.0 1992 36.3 23.5 11.2 11.0 11.0 10.9 11.0 11.5 36.7 36.4 36.4 36.8 10.0 10.0 10.0 10.8 10.9 1993 36.8 23.8 10.0 74.2 10.0 30.1 36.3 36.1 36.1 36.0 36.0 36.0 10.0 10.0 10.0 10.0 17.3 1994 35.9 36.0 36.3 36.0 36.0 22.1 10.0 10.4 36.2 36.0 36.0 36.0 10.0 10.0 10.0 10.0 13.7 1995 36.0 23.4 10.0 252.7 10.0 542.7 321.3 2434.1 2619.0 936.5 36.1 36.0 10.0 10.0 10.0 10.0 20.3 1996 36.0 36.0 50.1 36.0 277.1 47.2 36.1 1658.0 173.0 36.7 36.3 36.7 36.0 36.0 36.0 36.0 36.4 1997 38.8 38.6 825.1 4836.1 524.2 37.9 40.1 38.5 129.3 37.9 29.9 36.0 29.0 29.0 29.0 29.0 34.4 1998 37.7 37.2 38.0 38.4 233.3 341.0 38.1 38.4 1730.9 140.9 39.9 40.6 36.0 36.3 36.7 37.0 37.6 1999 40.3 40.1 48.3 137.2 819.9 325.4 38.5 586.2 39.0 40.6 40.2 37.7 36.0 36.0 36.9 37.7 37.9 2000 37.7 38.6 39.3 39.4 63.8 38.9 39.0 39.4 39.5 39.7 39.2 39.4 36.0 36.0 36.1 37.2 38.5 2001 39.0 37.9 39.1 39.4 39.5 23.5 12.1 11.2 37.4 37.2 38.1 38.0 10.0 10.0 10.0 10.8 14.8

04/21/04 Page 2 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

IHA Annual Summary Statistics (Cont)

Year 1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

1875 6248.2 5935.3 5615.8 4879.5 2774.7 0.0 0.1 276.0 152.0 11.0 4.3 2.0 36.0 131.5 -90.0 124.0 1876 2735.2 1450.1 1075.7 938.2 623.2 0.0 0.2 226.0 300.0 7.0 15.4 1.0 1.0 57.4 -33.8 138.0 1877 727.2 685.6 660.9 571.3 416.0 0.0 0.1 228.0 148.0 9.0 27.3 0.0 0.0 20.8 -15.8 142.0 1878 4357.8 4208.2 3934.8 3435.8 2744.1 0.0 0.0 285.0 136.0 3.0 11.3 11.0 12.6 218.4 -137.8 114.0 1879 6248.2 5935.3 5615.8 4879.5 2774.7 0.0 0.1 276.0 152.0 11.0 4.2 2.0 36.0 131.5 -90.5 124.0 1880 39207.9 28042.9 16393.1 5007.3 3008.3 0.0 0.1 278.0 13.0 5.0 2.2 4.0 33.3 487.3 -275.5 97.0 1881 2902.6 2737.5 2353.7 1711.7 1346.8 0.0 0.1 243.0 122.0 10.0 14.1 5.0 5.0 80.7 -50.0 130.0 1882 30546.5 18888.7 11121.4 5331.8 4096.0 0.0 0.0 275.0 47.0 3.0 3.3 6.0 28.8 802.1 -362.2 105.0 1883 20841.1 12213.4 9211.7 7595.6 5004.0 0.0 0.1 287.0 73.0 0.0 0.0 8.0 26.1 564.5 -325.4 115.0 1884 15625.4 13870.5 9809.2 4419.1 3153.8 0.0 0.1 241.0 360.0 1.0 32.0 7.0 24.6 542.0 -274.7 109.0 1885 3622.7 3454.6 3114.6 2323.6 1532.1 0.0 0.1 240.0 105.0 7.0 10.9 4.0 13.5 81.5 -50.0 124.0 1886 41984.2 36104.9 22281.4 9469.4 4711.1 0.0 0.1 278.0 48.0 3.0 2.0 7.0 20.3 687.6 -344.1 97.0 1887 3607.5 1933.2 1488.8 1233.4 888.6 0.0 0.2 224.0 44.0 8.0 22.4 4.0 2.8 60.7 -40.6 134.0 1888 1358.9 962.6 898.5 721.0 647.7 0.0 0.2 240.0 5.0 6.0 19.7 1.0 1.0 42.4 -33.8 137.0 1889 6774.3 5409.6 4470.2 3134.6 2479.4 0.0 0.1 276.0 68.0 11.0 5.8 6.0 15.7 173.9 -109.3 138.0 1890 2041.3 1726.2 1566.0 1404.2 1131.1 0.0 0.1 227.0 152.0 6.0 15.3 7.0 4.6 72.5 -41.2 116.0 1891 7763.5 4132.3 2278.4 1749.2 1265.7 0.0 0.1 280.0 64.0 7.0 27.0 6.0 6.7 108.3 -73.9 122.0 1892 2267.5 1971.4 1455.6 1173.3 946.8 0.0 0.1 224.0 51.0 14.0 12.1 4.0 1.8 57.2 -38.5 149.0 1893 7593.9 5951.7 4649.7 3902.4 3391.6 0.0 0.0 278.0 77.0 4.0 10.8 7.0 18.3 285.2 -147.3 120.0 1894 1644.7 1577.7 1432.9 1142.7 862.7 0.0 0.2 228.0 110.0 7.0 18.1 3.0 3.3 41.5 -26.4 138.0 1895 17921.7 13632.3 10126.4 5381.9 4549.0 0.0 0.0 276.0 122.0 4.0 3.8 7.0 26.0 502.0 -317.6 108.0 1896 15323.7 12387.8 8469.0 4566.3 3256.4 0.0 0.1 282.0 137.0 6.0 6.8 7.0 21.0 456.0 -222.0 110.0 1897 67934.6 47378.3 26381.2 8996.9 4468.5 0.0 0.1 283.0 2.0 4.0 17.0 11.0 15.1 922.4 -496.1 126.0 1898 15245.6 9800.5 6722.5 5552.4 4121.4 0.0 0.1 279.0 84.0 5.0 4.4 5.0 32.0 348.9 -225.5 141.0 1899 9292.0 6800.2 5981.3 4133.8 2989.1 0.0 0.1 281.0 40.0 4.0 5.5 8.0 17.3 288.8 -183.0 136.0 1900 9954.4 5902.0 3799.8 2961.4 2287.0 0.0 0.1 279.0 45.0 8.0 13.3 6.0 19.5 271.7 -155.3 134.0 1901 2513.0 2409.9 2322.3 1948.5 1238.8 0.0 0.1 242.0 117.0 8.0 16.5 4.0 9.5 61.8 -39.3 127.0 1975 692.0 470.0 214.4 101.3 82.7 0.0 0.4 310.0 86.0 3.0 70.7 0.0 0.0 12.2 -15.5 46.0 1976 37.0 37.0 36.9 36.3 25.3 0.0 0.7 54.0 275.0 2.0 0.5 0.0 0.0 1.4 -1.6 73.0 1977 26.0 26.0 25.6 24.7 18.6 0.0 0.6 140.0 302.0 2.0 107.0 0.0 0.0 0.9 -0.9 43.0 1978 81.0 81.0 80.4 78.5 76.1 0.0 0.3 39.0 129.0 2.0 107.0 0.0 0.0 2.1 -1.7 73.0 1979 692.0 470.0 214.4 101.3 82.7 0.0 0.4 310.0 86.0 3.0 70.7 0.0 0.0 12.3 -15.5 46.0 1980 16800.0 11406.7 6802.9 1615.9 664.2 0.0 0.1 23.0 13.0 3.0 83.7 2.0 5.0 240.7 -225.6 83.0 1981 44.0 39.0 38.9 37.6 157.7 0.0 0.6 87.0 301.0 2.0 107.0 0.0 0.0 1.8 -1.9 48.0 1982 16900.0 9320.0 4534.4 1815.8 1005.9 0.0 0.0 322.0 47.0 5.0 44.0 5.0 5.6 886.5 -769.0 40.0 1983 8880.0 4923.3 3771.4 2923.7 1468.0 0.0 0.0 84.0 73.0 10.0 25.2 7.0 8.6 341.9 -275.4 75.0 1984 9920.0 7366.7 4790.0 1224.5 726.8 0.0 0.2 25.0 361.0 4.0 75.0 3.0 5.0 487.3 -344.0 69.0 1985 63.0 56.0 47.0 40.7 38.9 0.0 1.0 177.0 309.0 2.0 107.0 0.0 0.0 1.7 -1.8 43.0 1986 20200.0 18466.7 10450.0 3610.0 1235.9 0.0 0.1 182.0 48.0 4.0 51.3 2.0 6.5 542.5 -419.0 66.0 1987 52.0 43.3 39.3 37.4 37.2 0.0 0.4 64.0 156.0 2.0 107.0 0.0 0.0 3.4 -2.9 23.0 1988 50.0 41.3 38.3 37.0 36.5 0.0 0.4 322.0 202.0 2.0 0.5 0.0 0.0 5.5 -7.3 19.0 1989 157.0 84.3 44.1 38.3 36.8 0.0 0.4 322.0 68.0 2.0 107.0 0.0 0.0 12.4 -11.8 31.0 1990 406.0 350.0 234.7 83.0 51.7 0.0 0.3 87.0 52.0 2.0 109.5 0.0 0.0 29.5 -34.1 15.0 1991 297.0 118.0 56.3 37.4 37.1 0.0 0.4 322.0 64.0 3.0 71.0 0.0 0.0 10.7 -10.4 51.0 1992 50.0 43.7 39.3 36.9 36.8 0.0 0.4 322.0 168.0 2.0 0.5 0.0 0.0 2.1 -2.1 70.0 1993 1460.0 673.3 294.3 76.3 44.9 0.0 0.3 322.0 22.0 2.0 125.5 1.0 1.0 57.6 -62.4 45.0 1994 41.0 37.7 36.9 36.3 36.1 0.0 0.3 76.0 182.0 2.0 107.0 0.0 0.0 4.8 -4.8 11.0 1995 9270.0 8106.7 5415.7 2624.7 2121.1 0.0 0.0 322.0 123.0 8.0 21.6 6.0 11.3 576.8 -566.9 55.0 1996 12400.0 9110.0 5490.0 1830.5 644.1 0.0 0.2 275.0 137.0 9.0 29.2 3.0 4.3 720.8 -535.9 40.0 1997 48900.0 31833.3 18024.3 5299.2 2113.4 0.0 0.1 217.0 2.0 5.0 50.0 6.0 4.5 1366.3 -988.0 56.0 1998 4260.0 3470.0 3171.4 1825.3 638.4 0.0 0.2 25.0 85.0 4.0 47.8 3.0 7.7 182.6 -160.7 81.0 1999 5260.0 2738.0 2118.6 1064.5 414.7 0.0 0.2 139.0 40.0 7.0 37.6 6.0 2.5 223.7 -175.0 84.0 2000 469.0 275.0 140.3 62.5 47.2 0.0 0.9 312.0 44.0 2.0 114.0 0.0 0.0 11.8 -11.4 56.0 2001 40.0 40.0 40.0 39.7 39.4 0.0 0.3 139.0 275.0 2.0 107.0 0.0 0.0 1.7 -1.7 45.0

04/21/04 Page 3 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Non-Parametric IHA Scorecard

(1) Gage A - 4435 South Fork American River Near Camino (Unregulated), April 2004

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Watershed area 1.00 Mean annual flow 1030.10 144.84 Mean flow/area 1030.10 144.84 Annual C. V. .93 .01 Flow predictability .40 .53 Constancy/predictability .49 .83 % of floods in 60d period .39 .39 flood-free season 54.00 127.00

MEDIANS COEFF. of DISP. DEVIATION FACTOR SIGNIFICANCE COUNT Pre Post Pre Post Medians C.V. Medians C.V. Parameter Group #1 October 168.9 36.8 .66 .06 .78 .91 .27 .26 November 239.9 23.8 1.07 .72 .90 .33 .25 .79 December 278.6 36.0 1.35 .78 .87 .42 .26 .63 January 387.1 36.0 2.96 1.62 .91 .45 .13 .61 February 657.4 37.1 2.29 7.09 .94 2.10 .06 .03 March 1364.0 30.1 1.19 1.52 .98 .28 .17 .67 April 2039.6 37.8 .60 1.03 .98 .71 .30 .67 May 2785.3 38.4 1.04 1.65 .99 .58 .19 .35 June 1279.3 38.0 1.92 1.25 .97 .35 .16 .58 July 338.1 36.8 1.62 .08 .89 .95 .20 .15 August 172.4 36.3 1.11 .07 .79 .94 .01 .09 September 192.3 36.4 .68 .05 .81 .92 .30 .12

Parameter Group #2 1-day minimum 58.3 11.0 1.13 1.73 .81 .53 .01 .21 3-day minimum 59.7 12.0 1.08 1.83 .80 .69 .02 .12 7-day minimum 60.3 12.3 1.08 1.88 .80 .74 .02 .15 30-day minimum 89.0 13.6 1.25 1.97 .85 .58 .01 .23 90-day minimum 162.4 18.8 .77 1.35 .88 .75 .15 .09 1-day maximum 6774.3 469.0 1.90 19.66 .93 9.33 .19 .00 3-day maximum 5901.9 350.0 1.76 20.92 .94 10.86 .17 .00 7-day maximum 4470.2 214.4 1.71 20.96 .95 11.26 .19 .00 30-day maximum 3435.8 78.5 1.05 22.65 .98 20.59 .03 .00 90-day maximum 2744.1 76.1 .82 8.24 .97 9.00 .04 .00 Number of zero days .0 .0 .00 .00 999999.00 999999.00 .00 .00 Base flow .1 .3 .62 .91 1.90 .46 .00 .28

Parameter Group #3 Date of minimum 276.0 322.0 .11 .36 .25 2.33 .02 .00 Date of maximum 73.0 68.0 .21 .31 .03 .47 .78 .10

Parameter Group #4 Low pulse count 6.0 2.0 .67 1.00 .67 .50 .01 .11 Low pulse duration 11.3 71.0 1.12 .98 5.26 .13 .00 .79 High pulse count 6.0 .0 .50 .00 1.00 1.00 .06 .09 High pulse duration 15.7 .0 1.37 .00 1.00 1.00 .10 .07 The low pulse threshold is 179.68 The high pulse level is 1319.25

Parameter Group #5 Rise rate 173.9 12.3 2.45 27.72 .93 10.33 .31 .00 Fall rate -109.3 -15.5 -2.14 -17.61 .86 7.22 .32 .00 Number of reversals 124.0 48.0 .19 .63 .61 2.37 .01 .00

04/21/04 Page 4 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Variance Data, Box and Whisker Format

October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

Pre-Impact Distribution 1-day min 41.6 108.6 73.4 91.9 146.5 166.3 398.8 497.5 189.6 73.4 25.9 40.6 23.4 23.5 24.0 25.8 27.3 25 pctile 112.5 170.3 211.9 217.4 377.4 746.5 1091.9 964.1 325.8 146.6 61.8 97.1 47.1 49.6 48.6 53.6 90.3 Median 168.9 239.9 278.6 387.1 657.4 1364.0 2039.6 2785.3 1279.4 338.1 172.5 192.3 58.3 59.7 60.4 89.0 162.4 75 pctile 224.5 427.2 589.3 1363.5 1883.3 2367.9 2321.3 3864.3 2779.0 695.2 253.5 227.3 113.0 114.2 113.8 164.7 215.5 1-day max 958.7 3521.0 4030.3 8147.1 7620.4 4167.2 4003.7 5176.2 6576.2 2984.0 727.7 449.8 210.1 213.5 222.6 384.6 500.0

Post-Impact Distribution 1-day min 10.0 10.3 10.0 10.0 10.0 10.9 10.0 9.7 10.0 9.9 10.4 10.1 5.8 5.8 8.6 9.6 9.8 25 pctile 36.0 21.6 11.2 16.0 14.3 17.6 12.2 11.5 36.1 36.0 36.0 36.0 10.0 10.0 10.0 10.0 11.8 Median 36.8 23.8 36.0 36.0 37.1 30.1 37.8 38.4 38.0 36.8 36.3 36.4 11.0 12.0 12.3 13.6 18.8 75 pctile 38.2 38.6 39.3 74.2 277.1 63.4 51.2 74.8 83.6 39.1 38.6 38.0 29.0 32.0 33.1 36.8 37.2 1-day max 47.5 917.6 1111.5 4836.1 2709.3 1089.7 1164.5 2434.1 2619.0 936.5 45.1 48.2 36.0 36.3 36.9 37.9 39.6

1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

Pre-Impact Distribution 1-day min 727.2 685.6 660.9 571.3 416.0 0.0 0.0 224.0 2.0 0.0 0.0 0.0 0.0 20.8 -496.1 97.0 25 pctile 2735.2 1971.4 1566.0 1404.2 1131.1 0.0 0.1 240.0 44.0 4.0 4.3 4.0 4.6 61.8 -274.7 114.0 Median 6774.3 5902.0 4470.2 3435.8 2744.1 0.0 0.1 276.0 73.0 6.0 11.3 6.0 15.7 173.9 -109.3 124.0 75 pctile 15625.4 12387.8 9211.7 5007.3 3391.6 0.0 0.1 279.0 122.0 8.0 17.0 7.0 26.0 487.3 -40.6 137.0 1-day max 67934.6 47378.3 26381.2 9469.4 5004.0 0.0 0.2 287.0 360.0 14.0 32.0 11.0 36.0 922.4 -15.8 149.0

Post-Impact Distribution 1-day min 26.0 26.0 25.6 24.7 18.6 0.0 0.0 23.0 2.0 2.0 0.5 0.0 0.0 0.9 -988.0 11.0 25 pctile 50.0 43.3 39.3 37.4 37.1 0.0 0.2 275.0 22.0 2.0 37.6 0.0 0.0 2.1 -275.4 40.0 Median 469.0 350.0 214.4 78.5 76.1 0.0 0.3 322.0 68.0 2.0 71.0 0.0 0.0 12.3 -15.5 48.0 75 pctile 9270.0 7366.7 4534.4 1815.8 664.2 0.0 0.4 39.0 137.0 4.0 107.0 3.0 5.0 341.9 -2.1 70.0 1-day max 48900.0 31833.3 18024.3 5299.2 2121.1 0.0 1.0 322.0 361.0 10.0 125.5 7.0 11.3 1366.3 -0.9 84.0

04/21/04 Page 5 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

IHA Percentile Data

(1) Gage A - 4435 South Fork American River Near Camino (Unregulated), April 2004 Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Pre-Impact Post-Impact 10% 25% 50% 75% 90% (75-25)/50 10% 25% 50% 75% 90% (75-25)/50

Parameter Group #1 October 81.56 112.54 168.89 224.47 406.45 .66 23.57 36.00 36.81 38.16 39.28 .06 November 123.09 170.33 239.93 427.21 1116.77 1.07 15.72 21.57 23.83 38.63 41.47 .72 December 115.47 211.88 278.60 589.32 2544.39 1.35 10.00 11.19 36.00 39.32 503.50 .78 January 155.88 217.44 387.13 1363.45 2987.22 2.96 10.25 15.97 36.00 74.19 514.87 1.62 February 266.46 377.39 657.36 1883.29 3328.53 2.29 10.00 14.29 37.07 277.14 893.81 7.09 March 556.94 746.47 1363.97 2367.85 3942.98 1.19 12.45 17.58 30.06 63.39 567.33 1.52 April 679.68 1091.91 2039.57 2321.27 2903.19 .60 10.56 12.20 37.77 51.17 124.35 1.03 May 632.65 964.07 2785.34 3864.27 4956.99 1.04 10.41 11.52 38.42 74.77 1463.60 1.65 June 219.07 325.82 1279.35 2779.03 4863.50 1.92 24.95 36.07 38.00 83.63 1900.09 1.25 July 115.83 146.56 338.06 695.19 2308.88 1.62 23.72 36.00 36.81 39.10 217.99 .08 August 52.28 61.79 172.45 253.50 423.86 1.11 22.61 36.00 36.26 38.58 40.33 .07 September 79.27 97.12 192.29 227.32 343.02 .68 23.21 36.00 36.43 38.00 40.86 .05

Parameter Group #2 1-day minimum 40.43 47.06 58.32 112.95 146.22 1.13 8.78 10.00 11.00 29.00 36.00 1.73 3-day minimum 40.93 49.58 59.67 114.22 147.41 1.08 9.09 10.00 12.00 32.00 36.00 1.83 7-day minimum 42.30 48.55 60.35 113.79 145.24 1.08 9.72 10.00 12.29 33.14 36.74 1.88 30-day minimum 41.10 53.57 88.98 164.71 171.48 1.25 10.00 10.00 13.60 36.83 37.30 1.97 90-day minimum 59.65 90.30 162.40 215.48 270.17 .77 10.04 11.82 18.82 37.23 38.25 1.35 1-day maximum 1587.56 2735.24 6774.34 15625.44 39763.18 1.90 39.40 50.00 469.00 9270.00 17560.00 19.66 3-day maximum 1352.60 1971.42 5901.95 12387.76 29655.24 1.76 37.53 43.33 350.00 7366.67 12818.66 20.92 7-day maximum 1040.26 1565.97 4470.21 9211.69 17570.73 1.71 36.86 39.29 214.43 4534.43 7532.28 20.96 30-day maximum 894.78 1404.21 3435.77 5007.30 7875.86 1.05 36.27 37.40 78.53 1815.80 3060.93 22.65 90-day maximum 642.79 1131.11 2744.10 3391.63 4581.41 .82 33.95 37.10 76.13 664.21 1597.10 8.24 Number of zero days .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 Base flow .03 .06 .11 .13 .15 .62 .03 .16 .31 .44 .71 .91

Parameter Group #3 Date of minimum 225.60 240.00 276.00 279.00 283.40 .11 139.80 275.00 322.00 39.00 84.60 .36 Date of maximum .40 44.00 73.00 122.00 152.00 .21 307.60 22.00 68.00 137.00 216.60 .31

Parameter Group #4 Low pulse count 2.60 4.00 6.00 8.00 11.00 .67 2.00 2.00 2.00 4.00 8.20 1.00 Low pulse duration 2.16 4.27 11.33 17.00 27.07 1.12 .50 37.57 71.00 107.00 110.40 .98 High pulse count 1.00 4.00 6.00 7.00 8.60 .50 .00 .00 .00 3.00 6.00 .00 High pulse duration 1.00 4.57 15.67 26.00 33.80 1.37 .00 .00 .00 5.00 7.85 .00

Parameter Group #5 Rise rate 42.23 61.78 173.91 487.25 710.54 2.45 1.65 2.12 12.26 341.92 753.94 27.72 Fall rate -347.71 -274.67 -109.26 -40.63 -32.29 -2.14 -607.31 -275.40 -15.52 -2.07 -1.66 -17.61 Number of reversals 103.40 114.00 124.00 137.00 141.20 .19 18.20 40.00 48.00 70.00 81.40 .63

04/21/04 Page 6 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Average flow for October Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1000 <>------<------>

900

800

700

600

500

400

Cubic Feet per Second 300

200

100 75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 7 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage flowNear for NovemberCamino (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000 Cubic Feet per Second 1000

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 8 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage flowNear for DecemberCamino (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 5000 <>------<------>

4000

3000

2000 Cubic Feet per Second

1000

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 9 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage flowNear for CaminoJanuary (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 9000 <>------<------>

8000

7000

6000

5000

4000

3000 Cubic Feet per Second

2000

1000

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 10 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage flowNear for FebruaryCamino (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 8000 <>------<------>

7000

6000

5000

4000

3000 Cubic Feet per Second 2000

1000

75th percen median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 11 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage Nearflow for Camino March (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 5000 <>------<------>

4000

3000

2000 Cubic Feet per Second

1000

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 12 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage Nearflow for Camino April (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 5000 <>------<------>

4000

3000

2000 Cubic Feet per Second

1000

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 13 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage Near flow for Camino May (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

3000

2000 Cubic Feet per Second

1000

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 14 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage Nearflow for Camino June (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7000 <>------<------>

6000

5000

4000

3000

Cubic Feet per Second 2000

1000

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 15 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage Nearflow for Camino July (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 3000 <>------<------>

2500

2000

1500

1000 Cubic Feet per Second

500

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 16 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverAverage flowNear for CaminoAugust (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 800 <>------<------>

700

600

500

400

300 Cubic Feet per Second 200

100

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 17 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Average flow for September Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 500 <>------<------>

400

300

200 Cubic Feet per Second

100

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 18 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 1-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 250 <>------<------>

200

150

100 Cubic Feet per Second

50 75th percen

median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 19 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 3-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 250 <>------<------>

200

150

100 Cubic Feet per Second

50 75th percen

median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 20 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 7-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 250 <>------<------>

200

150

100 Cubic Feet per Second

50 75th percen

median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 21 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 30-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Cubic Feet per Second 100

75th percen

median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 22 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 90-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 600 <>------<------>

500

400

300

200 Cubic Feet per Second

100

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 23 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 1-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 70000 <>------<------>

60000

50000

40000

30000

Cubic Feet per Second 20000

10000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 24 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 3-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 50000 <>------<------>

40000

30000

20000 Cubic Feet per Second

10000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 25 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American River7-day maximum Near streamflow Camino (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 30000 <>------<------>

25000

20000

15000

10000 Cubic Feet per Second

5000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 26 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American River30-day maximum Near streamflow Camino (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 10000 <>------<------>

9000

8000

7000

6000

5000

4000

Cubic Feet per Second 3000

2000 75th percen

1000

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 27 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

3000

2000 Cubic Feet per Second

1000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 28 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Zero streamflow days Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 29 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Base Flow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1.0 <>------<------>

0.9

0.8

0.7

0.6

0.5 75th percen 0.4

median

Cubic Feet per Second 0.3

0.2 25th percen 0.1

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 30 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Date of minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

median

300

25th percen

200 Julian Day

100

75th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 31 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Date of maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Julian Day 75th percen

100

median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 32 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Low Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 16 <>------<------>

8 Number

75th percen 4

2 median 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 33 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Low Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 140 <>------<------>

120

75th percen

100

80 median Days 60

40 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 34 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 High Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 12 <>------<------>

6 Number

4 75th percen

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 35 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverHigh PulseNear Duration Camino (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 Days

75th percen

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 36 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American River RiseNear Rate Camino (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1400 <>------<------>

1200

1000

800

CFS/Day 600

400 75th percen

200

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 37 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Fall Rate

75th percen 0 1875Pre-Impact<>------Period 1901 Post-Impact < 1975------Period 2001 > median

-100

-200

-300 25th percen

-400

-500 CFS/Day -600

-700

-800

-900

-1000 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 38 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Unregulated), April 2004 Reversals Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 160 <>------<------>

140

120

100

80 75th percen Number

60 median 40 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.ann, P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.baw

04/21/04 Page 39 of 160 (1) Gage A - South Fork American River at Slab Creek Res. Proposed Proj 184/UARP (Unregulated) versus 4435 South Fork American River Near Camino (Regulated)

A-4435 South Fork American River Near Camino (Unregulated), April 2004

70000

60000

50000

40000

30000

Cubic Feet per Second 20000

10000

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\1-GageA-Unreg\GA-U.dat

04/21/04 Page 40 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Errors

No Errors

04/21/04 Page 41 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

IHA Annual Summary Statistics

Year October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

1875 113.7 179.9 231.9 356.5 547.0 1036.2 1014.1 4106.7 3532.3 742.0 193.7 103.9 76.2 78.2 80.1 101.1 173.8 1876 383.2 394.6 286.7 254.4 283.3 472.7 725.5 985.7 243.7 83.1 127.9 76.4 50.1 55.7 60.6 74.7 73.4 1877 74.4 75.9 73.4 131.7 157.3 185.0 489.7 620.3 435.7 61.3 17.2 23.3 11.4 12.3 14.2 15.8 21.0 1878 24.1 100.0 644.8 1426.9 896.1 1971.8 2204.5 3427.3 2802.6 736.0 188.1 221.7 18.6 19.5 20.1 23.7 162.4 1879 115.1 179.9 231.9 356.5 547.0 1036.2 1014.1 4106.7 3532.3 742.0 193.7 103.9 76.2 74.5 70.8 88.1 153.2 1880 171.4 332.3 364.9 4878.0 2679.7 1367.0 2225.1 3055.3 2285.1 1023.0 191.7 110.4 64.8 67.5 70.5 87.4 106.7 1881 88.8 123.7 218.0 246.2 532.9 760.5 1619.0 1543.6 467.9 101.2 54.3 50.3 36.2 38.6 43.4 48.5 62.7 1882 133.8 1765.7 2427.3 1215.4 4024.6 2345.5 4109.4 5189.3 2907.0 949.1 290.2 396.0 53.8 61.1 82.1 130.8 330.6 1883 928.0 955.5 1720.8 1350.9 2358.3 3996.7 2337.5 5077.7 6689.4 3041.8 778.2 368.0 211.7 213.8 215.2 264.2 443.8 1884 302.2 3532.6 3963.8 1756.2 1215.2 1642.4 1657.0 3187.6 1740.3 461.9 148.1 106.2 77.2 82.7 101.3 106.2 144.0 1885 186.8 715.6 403.0 335.5 465.1 683.1 2347.2 1874.8 612.5 130.1 80.1 118.9 64.6 66.7 69.1 78.2 102.1 1886 130.3 252.5 584.6 1317.9 7494.2 4175.1 2387.4 2885.9 1844.7 422.3 139.8 141.8 84.1 85.7 92.7 103.6 135.6 1887 160.0 120.5 121.1 172.3 477.1 687.0 1335.3 1050.4 274.0 81.7 47.8 47.6 41.7 42.5 42.7 44.3 51.6 1888 69.1 106.0 274.4 387.8 382.3 633.2 848.0 779.4 389.6 77.0 45.0 46.6 33.5 33.7 34.7 39.1 45.7 1889 46.5 250.6 225.7 216.8 402.1 2856.5 2807.5 2098.9 1202.8 219.0 83.9 118.8 35.9 36.1 37.5 46.3 99.4 1890 190.8 231.7 205.0 377.4 342.1 947.3 1632.3 1130.2 715.2 146.3 63.3 54.6 40.6 42.8 44.4 51.6 58.2 1891 58.5 75.6 84.4 95.4 149.7 912.1 1181.6 1849.8 1202.9 247.6 90.6 59.9 44.5 45.0 46.2 50.7 72.4 1892 111.4 180.7 152.0 166.1 669.3 786.5 1406.6 719.1 233.8 139.0 50.6 32.4 28.5 28.8 29.4 32.4 43.9 1893 78.3 107.1 373.1 1238.3 988.6 2710.2 2808.0 4131.4 2542.0 726.7 219.6 107.2 38.0 38.5 39.0 72.0 110.2 1894 110.7 119.6 197.6 207.0 307.4 721.7 1071.1 1125.0 325.1 82.1 47.5 49.6 38.9 40.6 42.0 44.9 51.3 1895 58.8 237.9 412.4 2509.4 1350.3 3895.7 3355.8 5326.6 4964.5 2626.1 594.7 216.5 37.8 41.1 47.7 58.3 162.2 1896 125.0 161.6 776.3 1067.4 3158.3 2357.3 2935.8 4501.4 1851.9 534.4 180.8 126.5 108.8 110.2 103.1 110.2 127.4 1897 124.3 797.4 3190.7 8067.6 1717.4 1767.3 2331.6 2749.3 1350.1 319.7 135.9 99.6 83.9 86.0 88.8 95.2 112.5 1898 120.1 205.2 265.3 1513.9 1775.7 2581.0 2559.0 3669.1 5791.1 2301.6 363.9 245.1 82.7 84.7 90.2 119.8 195.8 1899 169.3 393.9 550.3 1273.3 2415.9 1699.0 2172.3 4267.8 2912.8 609.3 230.1 138.4 113.7 110.0 101.2 100.4 137.5 1900 116.4 189.4 171.8 1046.6 1864.0 1560.4 2449.5 3148.6 1156.6 230.4 109.0 100.0 77.3 68.6 65.1 80.6 105.2 1901 122.2 165.7 209.9 199.0 309.5 931.6 1335.5 1851.2 253.4 82.6 51.7 57.8 38.6 38.8 39.7 39.3 27.0 1975 38.2 21.6 18.8 18.3 19.4 63.4 68.4 67.4 83.6 36.9 36.0 36.4 17.0 17.0 17.0 18.0 18.8 1976 36.1 19.5 19.3 19.7 18.7 15.7 24.9 24.4 26.4 24.9 23.5 24.3 15.0 15.0 15.4 15.7 18.0 1977 24.7 15.8 15.0 16.0 15.5 11.4 10.9 9.7 10.0 9.9 10.4 10.1 7.1 8.0 8.6 9.6 9.8 1978 10.0 10.3 10.7 10.3 14.3 21.7 75.1 74.8 78.5 36.6 35.0 35.1 9.2 9.4 9.5 10.0 10.3 1979 38.1 21.6 18.8 18.3 19.4 63.4 68.4 67.4 83.6 36.9 36.0 36.4 17.0 17.0 17.0 18.0 18.8 1980 29.8 16.4 16.3 1563.5 342.4 28.3 71.6 83.9 79.8 28.6 45.1 48.2 11.0 12.3 13.0 16.1 19.0 1981 37.5 21.3 21.0 20.5 20.9 13.8 24.7 25.7 19.0 19.0 19.0 19.0 12.0 12.0 12.3 13.6 16.3 1982 19.0 15.3 423.1 12.0 1189.5 26.6 1164.5 1415.0 77.3 38.6 39.0 39.0 5.8 5.8 9.8 11.0 38.2 1983 47.5 41.4 336.9 117.4 524.1 666.1 49.0 1243.9 2577.0 526.5 41.0 42.0 17.0 17.7 18.4 37.9 39.6 1984 38.2 917.6 1111.5 112.9 37.5 38.2 37.8 38.5 38.0 39.1 38.6 39.1 33.0 35.0 36.9 37.1 37.7 1985 38.7 40.0 37.5 37.0 38.0 38.0 38.5 38.9 37.3 38.1 37.5 37.2 36.0 36.0 36.3 37.0 37.2 1986 37.2 41.8 36.9 39.1 2709.3 1089.7 51.2 37.4 39.3 39.2 38.6 37.3 26.0 32.0 33.1 36.8 37.1 1987 37.3 37.3 37.0 37.2 37.1 12.7 12.2 11.7 36.8 36.0 36.0 36.0 11.0 11.0 11.0 11.3 11.8 1988 36.0 23.6 10.0 10.0 10.0 14.2 10.0 10.4 36.0 36.6 36.5 36.3 10.0 10.0 10.0 10.0 10.0 1989 36.0 23.3 10.0 10.3 10.6 17.6 33.6 37.8 36.0 36.0 36.0 36.0 10.0 10.0 10.0 10.0 10.3 1990 36.1 36.0 36.0 36.0 86.4 31.3 12.2 10.4 36.0 36.0 36.0 36.0 10.0 10.0 10.0 10.0 17.6 1991 36.0 23.4 10.0 10.1 10.2 20.9 10.7 10.7 37.3 36.8 36.8 37.1 10.0 10.0 10.0 10.0 10.0 1992 36.3 23.5 11.2 11.0 11.0 10.9 11.0 11.5 36.7 36.4 36.4 36.8 10.0 10.0 10.0 10.8 10.9 1993 36.8 23.8 10.0 74.2 10.0 30.1 36.3 36.1 36.1 36.0 36.0 36.0 10.0 10.0 10.0 10.0 17.3 1994 35.9 36.0 36.3 36.0 36.0 22.1 10.0 10.4 36.2 36.0 36.0 36.0 10.0 10.0 10.0 10.0 13.7 1995 36.0 23.4 10.0 252.7 10.0 542.7 321.3 2434.1 2619.0 936.5 36.1 36.0 10.0 10.0 10.0 10.0 20.3 1996 36.0 36.0 50.1 36.0 277.1 47.2 36.1 1658.0 173.0 36.7 36.3 36.7 36.0 36.0 36.0 36.0 36.4 1997 38.8 38.6 825.1 4836.1 524.2 37.9 40.1 38.5 129.3 37.9 29.9 36.0 29.0 29.0 29.0 29.0 34.4 1998 37.7 37.2 38.0 38.4 233.3 341.0 38.1 38.4 1730.9 140.9 39.9 40.6 36.0 36.3 36.7 37.0 37.6 1999 40.3 40.1 48.3 137.2 819.9 325.4 38.5 586.2 39.0 40.6 40.2 37.7 36.0 36.0 36.9 37.7 37.9 2000 37.7 38.6 39.3 39.4 63.8 38.9 39.0 39.4 39.5 39.7 39.2 39.4 36.0 36.0 36.1 37.2 38.5 2001 39.0 37.9 39.1 39.4 39.5 23.5 12.1 11.2 37.4 37.2 38.1 38.0 10.0 10.0 10.0 10.8 14.8

04/21/04 Page 42 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

IHA Annual Summary Statistics (Cont)

Year 1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

1875 6689.2 6382.0 5990.9 5247.2 2962.3 0.0 0.1 268.0 152.0 4.0 14.3 3.0 23.3 142.7 -91.8 133.0 1876 3068.2 1619.1 1368.9 1157.8 736.5 0.0 0.2 210.0 300.0 5.0 18.0 2.0 1.0 61.6 -38.9 134.0 1877 953.9 914.7 882.7 749.3 526.1 0.0 0.1 259.0 152.0 10.0 22.5 0.0 0.0 23.8 -19.1 152.0 1878 4876.8 4622.6 4097.2 3714.1 2905.3 0.0 0.0 285.0 136.0 3.0 9.7 10.0 12.9 231.5 -142.3 120.0 1879 6689.2 6382.0 5990.9 5247.2 2962.3 0.0 0.1 268.0 152.0 4.0 13.0 3.0 23.3 143.7 -91.5 134.0 1880 39976.9 28643.2 16638.1 5062.1 3020.8 0.0 0.1 280.0 13.0 5.0 8.6 4.0 33.0 526.6 -274.2 101.0 1881 3369.7 3142.5 2706.3 1969.1 1368.2 0.0 0.1 268.0 115.0 4.0 26.8 6.0 5.8 83.9 -52.7 146.0 1882 30081.5 18665.7 10999.9 5452.3 4120.6 0.0 0.0 275.0 47.0 3.0 5.7 6.0 28.7 792.5 -373.4 113.0 1883 20147.1 11857.0 9560.4 7812.8 5111.6 0.0 0.1 291.0 73.0 0.0 0.0 7.0 29.4 579.7 -310.2 119.0 1884 15516.8 13558.5 9616.1 4345.5 3133.2 0.0 0.1 271.0 322.0 2.0 21.5 7.0 24.3 529.7 -262.2 109.0 1885 3986.7 3797.3 3400.7 2538.5 1697.6 0.0 0.1 239.0 106.0 4.0 20.5 2.0 28.0 86.5 -56.6 126.0 1886 40940.2 35452.2 21833.1 9357.4 4754.3 0.0 0.1 278.0 48.0 7.0 7.4 7.0 20.1 629.6 -361.7 103.0 1887 3552.5 2004.5 1841.4 1530.1 1039.3 0.0 0.1 245.0 44.0 7.0 24.1 7.0 3.4 65.3 -42.0 130.0 1888 1350.9 1064.0 1020.4 864.1 755.3 0.0 0.1 250.0 5.0 3.0 36.0 0.0 0.0 45.0 -35.4 149.0 1889 7025.3 5612.6 4615.6 3336.7 2639.3 0.0 0.0 276.0 68.0 6.0 11.3 6.0 16.0 169.5 -116.8 133.0 1890 2303.5 2014.6 1824.7 1632.3 1296.0 0.0 0.1 253.0 114.0 2.0 38.0 8.0 5.0 73.6 -45.5 113.0 1891 7976.5 4243.6 2489.7 1994.3 1425.4 0.0 0.1 279.0 64.0 4.0 19.0 8.0 5.5 120.0 -78.3 120.0 1892 2541.7 2018.1 1713.4 1406.6 1084.0 0.0 0.1 273.0 108.0 8.0 12.4 5.0 3.0 65.7 -42.6 149.0 1893 7543.9 5908.6 4777.7 4162.6 3533.0 0.0 0.0 278.0 77.0 3.0 21.7 7.0 17.9 273.3 -156.6 121.0 1894 1987.7 1902.7 1709.1 1347.2 983.5 0.0 0.1 251.0 110.0 4.0 34.3 3.0 4.7 46.8 -30.4 136.0 1895 18518.7 14001.7 10297.5 5525.9 4715.0 0.0 0.0 276.0 122.0 3.0 1.3 5.0 35.4 502.2 -328.7 108.0 1896 15636.7 12593.4 8620.7 4752.0 3365.5 0.0 0.1 274.0 137.0 5.0 11.0 7.0 20.9 468.9 -222.2 124.0 1897 67769.6 47261.6 26245.2 8917.7 4441.3 0.0 0.1 268.0 2.0 4.0 16.8 9.0 17.6 900.6 -512.7 125.0 1898 15418.6 9948.8 6918.8 5791.1 4282.9 0.0 0.1 279.0 84.0 2.0 14.5 5.0 31.2 353.0 -242.9 155.0 1899 9065.0 6967.4 6488.3 4472.3 3159.4 0.0 0.1 253.0 40.0 4.0 3.0 9.0 14.7 298.7 -187.5 144.0 1900 9780.4 5802.6 3953.1 3211.7 2444.9 0.0 0.1 274.0 45.0 9.0 8.1 7.0 16.1 278.7 -167.8 138.0 1901 3093.7 2911.3 2769.0 2262.8 1400.9 0.0 0.1 252.0 129.0 4.0 28.0 3.0 14.0 65.4 -48.0 140.0 1975 692.0 470.0 214.4 101.3 82.7 0.0 0.4 310.0 86.0 3.0 70.7 0.0 0.0 12.2 -15.5 46.0 1976 37.0 37.0 36.9 36.3 25.3 0.0 0.7 54.0 275.0 2.0 0.5 0.0 0.0 1.4 -1.6 73.0 1977 26.0 26.0 25.6 24.7 18.6 0.0 0.6 140.0 302.0 2.0 107.0 0.0 0.0 0.9 -0.9 43.0 1978 81.0 81.0 80.4 78.5 76.1 0.0 0.3 39.0 129.0 2.0 107.0 0.0 0.0 2.1 -1.7 73.0 1979 692.0 470.0 214.4 101.3 82.7 0.0 0.4 310.0 86.0 3.0 70.7 0.0 0.0 12.3 -15.5 46.0 1980 16800.0 11406.7 6802.9 1615.9 664.2 0.0 0.1 23.0 13.0 3.0 83.7 2.0 5.0 240.7 -225.6 83.0 1981 44.0 39.0 38.9 37.6 157.7 0.0 0.6 87.0 301.0 2.0 107.0 0.0 0.0 1.8 -1.9 48.0 1982 16900.0 9320.0 4534.4 1815.8 1005.9 0.0 0.0 322.0 47.0 5.0 44.0 5.0 5.6 886.5 -769.0 40.0 1983 8880.0 4923.3 3771.4 2923.7 1468.0 0.0 0.0 84.0 73.0 10.0 25.1 7.0 8.4 341.9 -275.4 75.0 1984 9920.0 7366.7 4790.0 1224.5 726.8 0.0 0.2 25.0 361.0 4.0 74.8 3.0 5.0 487.3 -344.0 69.0 1985 63.0 56.0 47.0 40.7 38.9 0.0 1.0 177.0 309.0 2.0 107.0 0.0 0.0 1.7 -1.8 43.0 1986 20200.0 18466.7 10450.0 3610.0 1235.9 0.0 0.1 182.0 48.0 4.0 51.3 2.0 6.5 542.5 -419.0 66.0 1987 52.0 43.3 39.3 37.4 37.2 0.0 0.4 64.0 156.0 2.0 107.0 0.0 0.0 3.4 -2.9 23.0 1988 50.0 41.3 38.3 37.0 36.5 0.0 0.4 322.0 202.0 2.0 0.5 0.0 0.0 5.5 -7.3 19.0 1989 157.0 84.3 44.1 38.3 36.8 0.0 0.4 322.0 68.0 3.0 71.0 0.0 0.0 12.4 -11.8 31.0 1990 406.0 350.0 234.7 83.0 51.7 0.0 0.3 87.0 52.0 2.0 109.5 0.0 0.0 29.5 -34.1 15.0 1991 297.0 118.0 56.3 37.4 37.1 0.0 0.4 322.0 64.0 3.0 71.0 0.0 0.0 10.7 -10.4 51.0 1992 50.0 43.7 39.3 36.9 36.8 0.0 0.4 322.0 168.0 2.0 0.5 0.0 0.0 2.1 -2.1 70.0 1993 1460.0 673.3 294.3 76.3 44.9 0.0 0.3 322.0 22.0 2.0 125.5 1.0 1.0 57.6 -62.4 45.0 1994 41.0 37.7 36.9 36.3 36.1 0.0 0.3 76.0 182.0 2.0 107.0 0.0 0.0 4.8 -4.8 11.0 1995 9270.0 8106.7 5415.7 2624.7 2121.1 0.0 0.0 322.0 123.0 9.0 19.1 6.0 11.2 576.8 -566.9 55.0 1996 12400.0 9110.0 5490.0 1830.5 644.1 0.0 0.2 275.0 137.0 9.0 29.1 2.0 5.5 720.8 -535.9 40.0 1997 48900.0 31833.3 18024.3 5299.2 2113.4 0.0 0.1 217.0 2.0 7.0 35.3 6.0 4.3 1366.3 -988.0 56.0 1998 4260.0 3470.0 3171.4 1825.3 638.4 0.0 0.2 25.0 85.0 4.0 47.3 4.0 5.0 182.6 -160.7 81.0 1999 5260.0 2738.0 2118.6 1064.5 414.7 0.0 0.2 139.0 40.0 6.0 43.5 5.0 2.8 223.7 -175.0 84.0 2000 469.0 275.0 140.3 62.5 47.2 0.0 0.9 312.0 44.0 2.0 114.0 0.0 0.0 11.8 -11.4 56.0 2001 40.0 40.0 40.0 39.7 39.4 0.0 0.3 139.0 275.0 2.0 107.0 0.0 0.0 1.7 -1.7 45.0

04/21/04 Page 43 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Non-Parametric IHA Scorecard

(2) Gage A - 4435 South Fork American River Near Camino (Natural), April 2004

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Watershed area 1.00 Mean annual flow 1049.88 144.84 Mean flow/area 1049.88 144.84 Annual C. V. .99 .01 Flow predictability .40 .53 Constancy/predictability .43 .83 % of floods in 60d period .43 .43 flood-free season 54.00 127.00

MEDIANS COEFF. of DISP. DEVIATION FACTOR SIGNIFICANCE COUNT Pre Post Pre Post Medians C.V. Medians C.V. Parameter Group #1 October 120.1 36.8 .76 .06 .69 .92 .10 .01 November 189.4 23.8 1.44 .72 .87 .50 .23 .59 December 274.4 36.0 1.38 .78 .87 .44 .23 .59 January 387.8 36.0 2.92 1.62 .91 .45 .12 .61 February 669.3 37.1 2.21 7.09 .94 2.20 .05 .03 March 1367.0 30.1 1.17 1.52 .98 .30 .16 .65 April 2172.3 37.8 .58 1.03 .98 .77 .32 .66 May 2885.9 38.4 1.03 1.65 .99 .60 .12 .28 June 1350.1 38.0 1.83 1.25 .97 .32 .17 .61 July 319.7 36.8 2.00 .08 .88 .96 .14 .14 August 135.9 36.3 1.03 .07 .73 .93 .00 .12 September 103.9 36.4 .81 .05 .65 .93 .00 .03

Parameter Group #2 1-day minimum 50.1 11.0 .79 1.73 .78 1.19 .02 .03 3-day minimum 55.7 12.0 .79 1.83 .78 1.31 .02 .02 7-day minimum 60.6 12.3 .81 1.88 .80 1.32 .02 .02 30-day minimum 74.7 13.6 .75 1.97 .82 1.62 .01 .00 90-day minimum 106.7 18.8 .89 1.35 .82 .52 .01 .09 1-day maximum 7025.3 469.0 1.79 19.66 .93 10.01 .15 .00 3-day maximum 5802.6 350.0 1.82 20.92 .94 10.48 .15 .00 7-day maximum 4615.6 214.4 1.67 20.96 .95 11.54 .11 .00 30-day maximum 3714.1 78.5 .97 22.65 .98 22.27 .02 .00 90-day maximum 2905.3 76.1 .77 8.24 .97 9.70 .04 .00 Number of zero days .0 .0 .00 .00 999999.00 999999.00 .00 .00 Base flow .1 .3 .59 .91 3.22 .53 .00 .15

Parameter Group #3 Date of minimum 271.0 322.0 .07 .36 .28 4.20 .01 .00 Date of maximum 77.0 68.0 .21 .31 .05 .47 .72 .08

Parameter Group #4 Low pulse count 4.0 3.0 .50 .67 .25 .33 .35 .44 Low pulse duration 14.5 71.0 .96 1.01 3.90 .05 .00 .89 High pulse count 6.0 .0 .67 .00 1.00 1.00 .07 .10 High pulse duration 16.1 .0 1.19 .00 1.00 1.00 .03 .03 The low pulse threshold is 137.15 The high pulse level is 1397.80

Parameter Group #5 Rise rate 169.5 12.3 2.58 27.72 .93 9.76 .27 .00 Fall rate -116.8 -15.5 -1.85 -17.61 .87 8.50 .26 .00 Number of reversals 130.0 48.0 .16 .63 .63 2.87 .02 .00

04/21/04 Page 44 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Variance Data, Box and Whisker Format

October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

Pre-Impact Distribution 1-day min 24.1 75.6 73.4 95.4 149.7 185.0 489.7 620.3 233.8 61.3 17.2 23.3 11.4 12.3 14.2 15.8 21.0 25 pctile 78.3 120.5 205.0 216.8 382.3 760.5 1181.6 1130.2 435.7 101.2 54.3 54.6 37.8 38.6 39.7 44.9 58.2 Median 120.1 189.4 274.4 387.8 669.3 1367.0 2172.3 2885.9 1350.1 319.7 135.9 103.9 50.1 55.7 60.6 74.7 106.7 75 pctile 169.3 393.9 584.6 1350.9 1864.0 2357.3 2449.5 4106.7 2907.0 742.0 193.7 138.4 77.3 82.7 88.8 101.1 153.2 1-day max 928.0 3532.6 3963.8 8067.6 7494.2 4175.1 4109.4 5326.6 6689.4 3041.8 778.2 396.0 211.7 213.8 215.2 264.2 443.8

Post-Impact mpact Di stribution 1-day min 10.0 10.3 10.0 10.0 10.0 10.9 10.0 9.7 10.0 9.9 10.4 10.1 5.8 5.8 8.6 9.6 9.8 25 pctile 36.0 21.6 11.2 16.0 14.3 17.6 12.2 11.5 36.1 36.0 36.0 36.0 10.0 10.0 10.0 10.0 11.8 Median 36.8 23.8 36.0 36.0 37.1 30.1 37.8 38.4 38.0 36.8 36.3 36.4 11.0 12.0 12.3 13.6 18.8 75 pctile 38.2 38.6 39.3 74.2 277.1 63.4 51.2 74.8 83.6 39.1 38.6 38.0 29.0 32.0 33.1 36.8 37.2 1-day max 47.5 917.6 1111.5 4836.1 2709.3 1089.7 1164.5 2434.1 2619.0 936.5 45.1 48.2 36.0 36.3 36.9 37.9 39.6

1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

Pre-Impact Distribution 1-day min 953.9 914.7 882.7 749.3 526.1 0.0 0.0 210.0 2.0 0.0 0.0 0.0 0.0 23.8 -512.7 101.0 25 pctile 3093.7 2018.1 1841.4 1632.3 1296.0 0.0 0.1 253.0 44.0 3.0 8.6 3.0 5.0 65.7 -262.2 119.0 Median 7025.3 5802.6 4615.6 3714.1 2905.3 0.0 0.1 271.0 77.0 4.0 14.5 6.0 16.1 169.5 -116.8 130.0 75 pctile 15636.7 12593.4 9560.4 5247.2 3533.0 0.0 0.1 278.0 122.0 5.0 22.5 7.0 24.3 502.2 -45.5 140.0 1-day max 67769.6 47261.6 26245.2 9357.4 5111.6 0.0 0.2 291.0 322.0 10.0 38.0 10.0 35.4 900.6 -19.1 155.0

Post-Impact Distribution 1-day min 26.0 26.0 25.6 24.7 18.6 0.0 0.0 23.0 2.0 2.0 0.5 0.0 0.0 0.9 -988.0 11.0 25 pctile 50.0 43.3 39.3 37.4 37.1 0.0 0.2 275.0 22.0 2.0 35.3 0.0 0.0 2.1 -275.4 40.0 Median 469.0 350.0 214.4 78.5 76.1 0.0 0.3 322.0 68.0 3.0 71.0 0.0 0.0 12.3 -15.5 48.0 75 pctile 9270.0 7366.7 4534.4 1815.8 664.2 0.0 0.4 39.0 137.0 4.0 107.0 3.0 5.0 341.9 -2.1 70.0 1-day max 48900.0 31833.3 18024.3 5299.2 2121.1 0.0 1.0 322.0 361.0 10.0 125.5 7.0 11.2 1366.3 -0.9 84.0

04/21/04 Page 45 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

IHA Percentile Data

(2) Gage A - 4435 South Fork American River Near Camino (Natural), April 2004 Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Pre-Impact Post-Impact 10% 25% 50% 75% 90% (75-25)/50 10% 25% 50% 75% 90% (75-25)/50

Parameter Group #1 October 56.08 78.31 120.11 169.27 318.43 .76 23.57 36.00 36.81 38.16 39.28 .06 November 95.18 120.49 189.36 393.86 1117.54 1.44 15.72 21.57 23.83 38.63 41.47 .72 December 113.76 204.96 274.40 584.61 2579.96 1.38 10.00 11.19 36.00 39.32 503.50 .78 January 159.22 216.79 387.84 1350.91 2983.13 2.92 10.25 15.97 36.00 74.19 514.87 1.62 February 258.13 382.31 669.26 1864.01 3331.55 2.21 10.00 14.29 37.07 277.14 893.81 7.09 March 601.09 760.52 1367.04 2357.27 3915.85 1.17 12.45 17.58 30.06 63.39 567.33 1.52 April 823.52 1181.57 2172.32 2449.54 3019.76 .58 10.56 12.20 37.77 51.17 124.35 1.03 May 767.33 1130.16 2885.86 4106.73 5100.02 1.03 10.41 11.52 38.42 74.77 1463.60 1.65 June 251.42 435.66 1350.05 2906.96 5129.81 1.83 24.95 36.07 38.00 83.63 1900.09 1.25 July 80.78 101.19 319.68 741.97 2366.53 2.00 23.72 36.00 36.81 39.10 217.99 .08 August 46.98 54.29 135.90 193.69 410.06 1.03 22.61 36.00 36.26 38.58 40.33 .07 September 43.77 54.61 103.90 138.38 269.71 .81 23.21 36.00 36.43 38.00 40.86 .05

Parameter Group #2 1-day minimum 26.52 37.80 50.10 77.30 109.78 .79 8.78 10.00 11.00 29.00 36.00 1.73 3-day minimum 26.91 38.60 55.70 82.73 110.04 .79 9.09 10.00 12.00 32.00 36.00 1.83 7-day minimum 27.55 39.66 60.56 88.81 101.65 .81 9.72 10.00 12.29 33.14 36.74 1.88 30-day minimum 30.68 44.94 74.70 101.10 121.97 .75 10.00 10.00 13.60 36.83 37.30 1.97 90-day minimum 40.55 58.19 106.72 153.20 222.71 .89 10.04 11.82 18.82 37.23 38.25 1.35 1-day maximum 1860.34 3093.70 7025.30 15636.70 40169.56 1.79 39.40 50.00 469.00 9270.00 17560.00 19.66 3-day maximum 1508.07 2018.13 5802.63 12593.40 30004.96 1.82 37.53 43.33 350.00 7366.67 12818.66 20.92 7-day maximum 1299.17 1841.40 4615.64 9560.40 17677.06 1.67 36.86 39.29 214.43 4534.43 7532.28 20.96 30-day maximum 1099.04 1632.32 3714.10 5247.20 8033.75 .97 36.27 37.40 78.53 1815.80 3060.93 22.65 90-day maximum 751.52 1295.98 2905.25 3533.04 4722.87 .77 33.95 37.10 76.13 664.21 1597.10 8.24 Number of zero days .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 Base flow .03 .05 .07 .09 .11 .59 .03 .16 .31 .44 .71 .91

Parameter Group #3 Date of minimum 243.80 253.00 271.00 278.00 281.00 .07 139.80 275.00 322.00 39.00 84.60 .36 Date of maximum 358.80 44.00 77.00 122.00 152.00 .21 307.60 22.00 68.00 137.00 216.60 .31

Parameter Group #4 Low pulse count 2.00 3.00 4.00 5.00 8.20 .50 2.00 2.00 3.00 4.00 9.00 .67 Low pulse duration 2.67 8.60 14.50 22.50 34.60 .96 .50 35.29 71.00 107.00 110.40 1.01 High pulse count 1.60 3.00 6.00 7.00 9.00 .67 .00 .00 .00 3.00 6.00 .00 High pulse duration .80 5.00 16.14 24.29 31.56 1.19 .00 .00 .00 5.00 6.89 .00

Parameter Group #5 Rise rate 46.46 65.70 169.50 502.20 662.18 2.58 1.65 2.12 12.26 341.92 753.94 27.72 Fall rate -364.01 -262.20 -116.84 -45.49 -34.42 -1.85 -607.31 -275.40 -15.52 -2.07 -1.66 -17.61 Number of reversals 107.00 119.00 130.00 140.00 149.60 .16 18.20 40.00 48.00 70.00 81.40 .63

04/21/04 Page 46 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for October Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1000 <>------<------>

900

800

700

600

500

400

Cubic Feet per Second 300

200

100 75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 47 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork AmericanAverage River flow Nearfor November Camino (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000 Cubic Feet per Second 1000

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 48 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for December Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000 Cubic Feet per Second 1000

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 49 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for January Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 9000 <>------<------>

8000

7000

6000

5000

4000

3000 Cubic Feet per Second

2000

1000

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 50 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for February Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 8000 <>------<------>

7000

6000

5000

4000

3000 Cubic Feet per Second 2000

1000

75th percen median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 51 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for March Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 5000 <>------<------>

4000

3000

2000 Cubic Feet per Second

1000

75th percen median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 52 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for April Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 5000 <>------<------>

4000

3000

2000 Cubic Feet per Second

1000

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 53 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for May Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

3000

2000 Cubic Feet per Second

1000

75thmedian percen 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 54 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for June Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7000 <>------<------>

6000

5000

4000

3000

Cubic Feet per Second 2000

1000

75th percen median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 55 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American AverageRiver flow Near for JulyCamino (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000 Cubic Feet per Second 1000

75thmedian percen 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 56 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork AmericanAverage River flow Near for August Camino (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 800 <>------<------>

700

600

500

400

300 Cubic Feet per Second 200

100

75thmedian percen 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 57 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Average flow for September Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Cubic Feet per Second 100

75thmedian percen 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 58 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 1-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 250 <>------<------>

200

150

100 Cubic Feet per Second

50 75th percen

median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 59 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 3-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 250 <>------<------>

200

150

100 Cubic Feet per Second

50 75th percen

median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 60 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 7-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 250 <>------<------>

200

150

100 Cubic Feet per Second

50 75th percen

median 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 61 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 30-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 300 <>------<------>

250

200

150

100 Cubic Feet per Second

50 75th percen

median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 62 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 90-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 500 <>------<------>

400

300

200 Cubic Feet per Second

100

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 63 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 1-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 70000 <>------<------>

60000

50000

40000

30000

Cubic Feet per Second 20000

10000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 64 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 3-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 50000 <>------<------>

40000

30000

20000 Cubic Feet per Second

10000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 65 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American7-day River maximum Near streamflow Camino (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 30000 <>------<------>

25000

20000

15000

10000 Cubic Feet per Second

5000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 66 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American30-day River maximum Near streamflow Camino (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 10000 <>------<------>

9000

8000

7000

6000

5000

4000

Cubic Feet per Second 3000

2000 75th percen

1000

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 67 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

3000

2000 Cubic Feet per Second

1000 75th percen

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 68 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Zero streamflow days Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 69 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Base Flow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1.0 <>------<------>

0.9

0.8

0.7

0.6

0.5 75th percen 0.4

median

Cubic Feet per Second 0.3

0.2 25th percen 0.1

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 70 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Date of minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

median

300

25th percen

200 Julian Day

100

75th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 71 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Date of maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Julian Day 75th percen

100

median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 72 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Low Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 4

3 median

2 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 73 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Low Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 140 <>------<------>

120

75th percen

100

80 median Days 60

40 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 74 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 High Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 3

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 75 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverHigh Pulse Near Duration Camino (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 Days

75th percen

0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 76 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA

A-4435 South Fork American RiverRise NearRate Camino (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1400 <>------<------>

1200

1000

800

CFS/Day 600

400 75th percen

200

median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 77 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Fall Rate

75th percen 0 1875Pre-Impact<>------Period 1901 Post-Impact < 1975------Period 2001 > median

-100

-200

-300 25th percen

-400

-500 CFS/Day -600

-700

-800

-900

-1000 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 78 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

Standard IHA A-4435 South Fork American River Near Camino (Natural), April 2004 Reversals Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 160 <>------<------>

140

120

100

80 75th percen Number

60 median 40 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.ann, P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.baw

04/21/04 Page 79 of 160 (2) Gage A - South Fork American River at Slab Creek Reservoir (Natural) versus 4435 South Fork American River Near Camino (Regulated)

A-4435 South Fork American River Near Camino (Natural), April 2004

70000

60000

50000

40000

30000

Cubic Feet per Second 20000

10000

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\2-GageA-Nat\GA-N.dat

04/21/04 Page 80 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Errors

No Errors

04/21/04 Page 81 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

IHA Annual Summary Statistics

Year October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

1875 202.1 269.6 307.0 452.6 725.6 1299.2 1160.6 4084.3 3350.1 735.4 263.1 242.4 136.7 138.2 147.0 199.5 260.4 1876 439.0 474.3 413.2 312.7 340.6 469.1 655.6 791.1 200.4 102.9 112.8 100.5 59.7 63.1 66.7 76.2 100.7 1877 105.7 117.5 86.0 149.3 174.8 187.2 413.9 516.6 328.8 76.7 28.2 44.9 24.2 24.4 25.3 28.2 38.2 1878 42.2 143.5 723.5 1710.3 1134.7 2316.1 2516.2 3305.0 2647.7 721.2 246.2 327.5 26.6 27.1 28.0 41.9 252.9 1879 205.5 269.6 307.0 452.6 725.6 1299.2 1160.6 4084.3 3350.1 735.4 263.1 242.4 136.7 138.2 128.4 173.2 246.5 1880 249.6 425.9 433.3 5306.2 3822.6 1628.8 2139.5 3037.0 2252.0 991.2 275.1 237.3 110.0 110.3 110.7 163.0 195.2 1881 159.4 195.3 271.2 337.6 616.5 837.4 1501.4 1367.1 408.5 159.4 63.7 112.1 47.9 52.3 56.9 63.5 101.7 1882 186.8 1815.0 2651.1 1426.4 5070.3 2765.6 4920.1 5436.6 2903.0 949.8 340.6 484.7 73.0 81.7 103.7 183.5 404.7 1883 1022.9 1113.9 2185.3 1670.1 3391.0 5286.0 2976.2 5382.6 6722.2 3064.4 776.3 449.4 243.8 247.0 256.5 428.0 548.0 1884 503.0 3910.2 5016.5 2060.7 1440.0 1847.5 1628.0 3146.0 1689.0 488.3 217.6 211.8 148.3 149.9 151.1 168.9 225.2 1885 268.1 811.4 567.0 421.0 563.2 746.3 2268.2 1689.4 536.1 182.9 115.6 216.7 77.2 78.1 80.8 105.1 159.9 1886 187.1 326.5 660.5 1412.2 9493.6 4666.8 2334.0 2863.5 1779.9 447.3 234.2 263.3 106.0 107.6 120.7 187.7 199.7 1887 244.5 188.7 156.8 216.9 563.2 789.7 1167.2 859.9 239.8 129.0 58.0 96.5 56.4 56.5 56.7 57.9 78.2 1888 112.7 161.4 319.9 481.3 406.5 615.5 729.6 678.8 342.9 136.4 56.0 80.7 49.8 51.3 52.3 55.9 71.7 1889 79.2 307.7 253.1 252.7 445.6 3133.7 2666.5 1957.4 1099.2 251.4 159.3 205.1 51.5 52.4 54.6 79.3 165.7 1890 243.8 324.1 222.0 434.1 422.6 1012.7 1441.0 1004.3 637.0 190.0 90.6 135.5 64.9 66.5 67.2 77.2 105.3 1891 101.0 123.1 106.0 111.1 167.7 1087.8 1149.9 1661.8 1069.0 265.7 122.3 147.7 59.9 60.6 62.2 92.2 109.4 1892 160.6 240.1 172.1 196.9 812.9 845.4 1207.8 573.0 207.9 142.6 56.0 100.3 52.1 52.3 52.8 56.0 75.8 1893 120.3 152.0 490.2 1665.4 1353.1 2985.6 2890.1 3927.7 2430.2 680.5 270.5 236.3 49.7 50.7 50.9 112.9 201.8 1894 187.6 205.2 257.6 253.1 417.7 750.4 944.4 979.1 315.8 147.9 57.0 85.3 53.8 54.9 56.0 56.9 79.5 1895 98.5 307.6 532.9 3121.3 1486.0 4710.6 3597.8 5533.5 4840.8 2654.1 603.7 354.9 53.9 62.5 65.7 98.1 303.2 1896 307.0 270.7 866.5 1375.3 3602.2 2675.4 3006.8 4532.3 1862.1 554.6 243.0 249.5 177.9 179.2 178.6 208.0 228.1 1897 212.5 893.7 3925.4 9484.0 2030.9 1902.3 2268.7 2742.0 1332.4 367.6 193.3 175.6 143.3 145.1 144.4 158.7 183.3 1898 191.4 295.2 330.5 1932.8 2520.1 2858.9 2882.1 3831.8 5736.5 2354.2 445.1 370.8 125.2 128.2 134.4 191.4 271.9 1899 294.6 533.3 661.8 1565.9 3153.6 2023.2 2346.0 4110.7 2869.4 658.9 323.2 264.8 200.4 202.6 184.6 200.9 242.3 1900 215.0 287.6 240.2 1241.1 2452.3 1807.2 2392.6 3028.3 1127.9 323.9 176.3 186.0 151.4 151.5 136.1 164.7 179.9 1901 197.1 247.5 270.9 275.9 463.4 986.3 1273.3 1636.2 286.3 164.7 74.3 106.8 69.1 69.5 70.7 72.9 113.8 1975 591.6 706.5 992.9 1180.2 1064.8 1406.1 1874.0 3506.5 2784.8 1182.6 1041.4 1054.3 114.0 371.0 505.4 531.5 756.3 1976 579.4 784.4 1105.0 748.7 647.7 530.6 522.2 733.7 492.6 938.5 958.6 576.6 108.0 109.3 246.6 407.6 331.2 1977 400.9 271.3 320.0 188.3 124.7 123.9 255.1 294.7 228.1 88.2 141.5 244.0 15.0 15.0 19.9 45.3 131.8 1978 275.3 106.2 485.3 1340.7 887.8 2023.8 2833.3 3367.4 2226.1 986.3 736.5 541.8 27.0 29.0 30.4 102.5 264.0 1979 593.6 706.5 992.9 1180.2 1064.8 1406.1 1874.0 3506.5 2784.8 1182.6 1041.4 1054.3 114.0 371.0 505.4 572.5 613.5 1980 588.0 477.0 798.8 4027.5 3299.7 2343.2 2706.3 3075.2 1964.4 1584.5 965.3 1327.6 109.0 119.3 281.4 443.0 604.1 1981 657.5 638.6 885.0 760.2 810.0 993.2 987.6 907.7 583.1 849.5 841.9 758.5 98.0 127.3 293.9 426.2 609.6 1982 430.6 1275.5 2330.6 2388.7 4370.0 3413.9 5381.7 5166.8 3511.0 1723.1 1310.6 1134.2 110.0 111.0 200.0 394.1 1058.4 1983 877.9 1846.8 2601.9 2221.0 3790.4 5561.3 4278.7 5443.9 6496.0 3648.4 1483.4 1122.6 324.0 397.3 456.0 845.1 1120.1 1984 934.9 3806.0 4632.6 2974.5 2209.0 2363.6 2491.0 2410.0 1482.7 866.5 1107.6 1003.5 396.0 568.0 695.1 658.3 813.4 1985 645.9 942.8 842.0 743.7 1318.4 1017.8 1533.3 1231.7 582.6 963.0 917.6 888.7 250.0 339.0 419.3 455.3 585.1 1986 452.9 452.8 1082.6 1461.2 6612.9 5067.4 2993.3 3074.5 2686.0 1182.7 1078.9 1052.3 125.0 135.0 273.1 376.3 629.9 1987 522.9 639.2 729.0 409.6 846.4 646.8 878.3 859.7 774.2 760.8 722.5 447.4 108.0 152.0 334.9 223.5 198.1 1988 204.3 107.4 464.2 554.0 743.3 650.3 546.1 474.3 432.6 409.3 408.2 453.9 101.0 101.0 102.6 107.4 251.7 1989 216.3 290.8 414.7 415.8 539.1 2329.5 1836.4 1258.2 1059.4 1012.1 1021.6 948.3 107.0 118.0 121.9 184.4 304.6 1990 306.2 323.2 499.2 582.6 592.4 869.7 930.8 772.9 666.8 932.8 916.9 680.4 98.0 110.7 127.7 291.2 373.2 1991 516.2 498.2 524.7 426.1 425.1 862.5 874.0 1103.1 811.2 622.8 712.0 721.8 114.0 154.0 325.3 379.0 450.0 1992 532.7 360.8 527.9 568.2 822.2 661.7 873.6 670.0 457.2 456.7 521.4 411.0 111.0 111.0 111.7 330.7 386.0 1993 388.3 373.4 631.5 1609.4 1369.0 2552.6 2712.7 3371.9 2731.3 1175.5 985.2 843.6 133.0 207.7 232.4 356.0 464.0 1994 480.6 581.3 702.8 506.8 656.2 596.3 733.0 716.4 531.6 460.4 459.9 462.2 165.0 243.0 334.3 430.4 423.4 1995 443.3 365.4 465.7 2743.8 1971.8 4452.9 3805.0 6159.4 5547.3 3240.3 1387.2 1401.3 156.0 160.3 160.9 365.4 422.6 1996 850.6 595.7 738.4 1214.9 2811.8 3121.0 3142.0 4824.8 2151.1 953.4 831.7 865.0 328.0 392.0 482.7 540.4 697.4 1997 740.1 812.0 3563.1 9672.6 3550.4 2649.7 1831.7 1814.8 1698.0 912.4 915.5 1260.3 198.0 230.3 284.3 590.6 631.5 1998 694.2 489.8 667.4 1943.9 3078.2 3161.3 3338.3 3728.1 5472.0 3163.2 1719.0 1369.0 145.0 177.7 397.9 466.6 603.9 1999 554.4 657.3 1071.5 1240.8 3261.4 3012.6 2921.7 3515.5 2536.0 1242.7 1502.7 1164.6 154.0 275.0 354.1 553.7 742.9 2000 677.7 711.5 777.0 1148.2 2242.2 2124.7 1851.4 2399.0 1588.8 1037.1 1371.5 1196.7 154.0 186.7 238.7 324.7 622.4 2001 404.4 1092.9 1217.9 543.1 477.4 726.0 943.7 1072.9 353.3 344.7 298.2 205.9 128.0 129.0 129.3 205.9 273.0

04/21/04 Page 82 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

IHA Annual Summary Statistics (Cont)

Year 1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

1875 6565.4 6099.7 5778.2 5065.6 2953.7 0.0 0.1 276.0 85.0 8.0 4.9 4.0 19.3 160.3 -108.6 128.0 1876 2866.3 1553.9 1096.5 961.6 649.5 0.0 0.2 223.0 300.0 6.0 17.7 1.0 1.0 63.2 -36.0 134.0 1877 746.6 703.0 677.9 588.1 432.8 0.0 0.1 227.0 148.0 8.0 22.1 0.0 0.0 21.4 -17.3 146.0 1878 5288.6 4479.4 4002.5 3544.7 2966.9 0.0 0.0 285.0 116.0 3.0 11.3 11.0 12.8 255.4 -157.3 110.0 1879 6565.4 6099.7 5778.2 5065.6 2953.7 0.0 0.1 276.0 85.0 8.0 4.8 4.0 19.3 160.3 -109.1 128.0 1880 41800.1 30182.7 17834.6 5505.5 3628.1 0.0 0.1 279.0 13.0 4.0 2.5 4.0 34.0 545.4 -312.1 99.0 1881 2956.0 2788.5 2408.3 1761.7 1463.3 0.0 0.1 243.0 122.0 5.0 26.6 5.0 4.4 83.3 -55.7 134.0 1882 40158.7 24683.3 14262.4 6281.7 4899.7 0.0 0.0 275.0 47.0 3.0 4.0 5.0 35.2 944.6 -437.5 107.0 1883 24065.8 14478.4 9585.3 7849.7 5338.9 0.0 0.1 287.0 73.0 0.0 0.0 9.0 23.7 704.2 -383.8 113.0 1884 18906.8 17083.1 12100.0 5423.7 3730.3 0.0 0.1 238.0 360.0 1.0 32.0 8.0 21.3 620.7 -306.1 111.0 1885 3738.0 3567.2 3229.1 2415.5 1603.7 0.0 0.1 240.0 105.0 8.0 9.9 5.0 10.6 89.3 -55.8 120.0 1886 52166.6 45680.8 28507.2 11441.8 5508.7 0.0 0.1 278.0 48.0 5.0 2.2 6.0 23.8 801.0 -397.5 103.0 1887 4065.6 2206.2 1523.0 1266.3 964.1 0.0 0.2 224.0 44.0 5.0 34.0 5.0 1.8 71.6 -46.0 132.0 1888 1577.5 989.2 925.1 763.0 678.9 0.0 0.2 240.0 5.0 7.0 17.1 1.0 1.0 49.7 -39.7 130.0 1889 7099.7 5675.1 4746.9 3440.3 2622.7 0.0 0.1 276.0 68.0 7.0 10.3 5.0 16.6 198.5 -128.6 136.0 1890 2170.1 1803.6 1606.8 1441.0 1174.1 0.0 0.1 227.0 152.0 6.0 16.7 8.0 2.1 85.8 -48.2 122.0 1891 8475.2 4520.3 2471.8 1790.3 1335.2 0.0 0.1 280.0 64.0 7.0 29.0 6.0 5.2 127.4 -81.0 120.0 1892 3164.0 2446.5 1722.7 1207.8 1028.2 0.0 0.1 233.0 51.0 13.0 13.2 3.0 2.0 71.3 -46.8 139.0 1893 7885.4 6245.1 4878.5 3955.7 3533.1 0.0 0.0 286.0 77.0 4.0 12.5 7.0 19.1 340.1 -179.3 116.0 1894 1663.4 1595.8 1469.7 1172.8 901.2 0.0 0.2 228.0 110.0 7.0 18.1 2.0 3.5 49.8 -30.1 132.0 1895 19304.5 14511.9 10770.1 5760.7 4934.8 0.0 0.0 276.0 122.0 5.0 2.8 5.0 36.0 574.2 -362.4 114.0 1896 16093.5 12921.7 8791.0 4753.3 3461.4 0.0 0.1 279.0 137.0 5.0 7.0 6.0 24.8 515.1 -263.6 120.0 1897 75832.0 52347.5 29219.6 10394.9 5282.2 0.0 0.1 258.0 2.0 4.0 17.8 10.0 16.7 1060.8 -593.9 134.0 1898 16057.4 10524.4 7129.5 5736.5 4350.5 0.0 0.1 275.0 84.0 5.0 4.4 7.0 23.6 455.6 -294.8 151.0 1899 12367.9 9131.6 6098.3 4263.2 3141.7 0.0 0.1 238.0 40.0 5.0 2.6 9.0 16.2 381.8 -241.4 136.0 1900 12732.0 7739.7 4903.3 3083.7 2510.7 0.0 0.1 278.0 45.0 6.0 15.2 7.0 17.7 340.4 -187.0 138.0 1901 2608.4 2513.9 2373.1 2013.8 1319.0 0.0 0.1 242.0 118.0 9.0 13.2 2.0 16.5 76.9 -45.8 133.0 1975 4020.0 3946.7 3940.0 3820.0 2835.4 0.0 0.4 302.0 85.0 1.0 1.0 23.0 4.8 270.8 -260.9 182.0 1976 3010.0 1495.3 1191.4 1111.3 911.5 0.0 0.3 290.0 301.0 1.0 5.0 2.0 1.0 202.0 -197.3 204.0 1977 1290.0 913.0 500.0 410.2 331.1 0.0 0.1 247.0 291.0 61.0 3.6 0.0 0.0 239.5 -215.4 158.0 1978 4730.0 4196.7 4014.3 3595.7 2920.0 0.0 0.0 331.0 17.0 15.0 4.0 15.0 8.7 328.0 -281.5 176.0 1979 4020.0 3946.7 3940.0 3820.0 2835.4 0.0 0.4 302.0 85.0 1.0 1.0 23.0 4.8 270.4 -260.9 182.0 1980 19300.0 15876.7 10504.3 4342.3 3348.2 0.0 0.2 289.0 14.0 7.0 1.9 17.0 11.9 429.8 -419.9 177.0 1981 3630.0 2413.3 1599.9 1155.9 1285.9 0.0 0.4 25.0 86.0 5.0 1.8 6.0 2.3 260.3 -255.3 181.0 1982 21700.0 14510.0 9117.1 5896.7 4875.1 0.0 0.1 305.0 47.0 3.0 2.7 17.0 13.8 563.7 -488.9 157.0 1983 15800.0 10810.0 7755.7 6826.3 5542.1 0.0 0.1 282.0 73.0 0.0 0.0 12.0 23.5 517.3 -370.5 140.0 1984 15500.0 12853.3 9974.3 5239.7 3934.7 0.0 0.3 165.0 361.0 0.0 0.0 13.0 16.7 471.7 -446.5 195.0 1985 3420.0 2563.3 2114.3 1575.0 1332.0 0.0 0.4 317.0 39.0 0.0 0.0 11.0 3.4 200.7 -191.1 199.0 1986 28200.0 26733.3 17341.4 8532.7 4975.8 0.0 0.1 310.0 48.0 5.0 1.6 9.0 17.8 491.2 -405.9 168.0 1987 2010.0 1730.0 1265.1 999.1 846.3 0.0 0.5 261.0 73.0 9.0 1.6 3.0 1.7 200.8 -204.5 216.0 1988 1540.0 1356.7 956.6 764.5 669.8 0.0 0.2 325.0 350.0 6.0 11.2 1.0 1.0 133.5 -121.8 185.0 1989 5420.0 3990.0 3528.6 2601.7 1833.4 0.0 0.1 13.0 85.0 14.0 2.9 11.0 5.9 282.1 -293.4 208.0 1990 1790.0 1463.3 1345.7 975.0 863.7 0.0 0.2 29.0 219.0 16.0 2.4 4.0 1.3 224.0 -241.8 208.0 1991 2950.0 2152.0 1372.7 1164.2 961.9 0.0 0.5 283.0 65.0 10.0 1.5 6.0 1.2 220.6 -218.6 216.0 1992 2580.0 1933.3 1486.1 931.4 834.8 0.0 0.2 308.0 52.0 16.0 2.3 5.0 1.2 203.3 -198.9 229.0 1993 6330.0 5176.7 3832.9 3408.7 3099.8 0.0 0.2 279.0 22.0 5.0 1.2 10.0 15.0 285.3 -263.0 202.0 1994 1210.0 1032.3 893.6 782.6 691.9 0.0 0.6 278.0 132.0 1.0 2.0 0.0 0.0 148.3 -146.2 221.0 1995 14800.0 13066.7 9830.0 6201.3 5395.1 0.0 0.1 363.0 123.0 10.0 2.4 18.0 13.2 438.1 -398.4 178.0 1996 16900.0 13400.0 8890.0 4883.7 3745.8 0.0 0.3 6.0 137.0 0.0 0.0 9.0 16.6 390.7 -325.7 185.0 1997 57100.0 40300.0 24671.4 10351.0 5759.0 0.0 0.1 313.0 2.0 1.0 1.0 18.0 10.6 691.8 -637.0 183.0 1998 7260.0 6690.0 6531.4 5647.7 4342.2 0.0 0.2 324.0 85.0 4.0 1.5 12.0 19.6 386.3 -331.1 203.0 1999 8510.0 5873.3 4430.0 3701.0 3141.9 0.0 0.2 275.0 40.0 2.0 0.5 16.0 11.8 386.9 -371.3 208.0 2000 6480.0 5450.0 4035.7 2727.7 2234.0 0.0 0.2 9.0 45.0 2.0 2.0 28.0 5.5 362.5 -370.9 187.0 2001 2330.0 1973.3 1614.3 1278.2 973.5 0.0 0.2 268.0 347.0 19.0 3.4 14.0 1.8 245.7 -231.7 187.0

04/21/04 Page 83 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Non-Parametric IHA Scorecard

(3) Gage B - 4445 South Fork American River Near Placerville (Unregulated), April 2004

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Watershed area 1.00 Mean annual flow 1199.96 1432.95 Mean flow/area 1199.96 1432.95 Annual C. V. .88 .58 Flow predictability .40 .42 Constancy/predictability .50 .71 % of floods in 60d period .39 .39 flood-free season 56.00 18.00

MEDIANS COEFF. of DISP. DEVIATION FACTOR SIGNIFICANCE COUNT Pre Post Pre Post Medians C.V. Medians C.V. Parameter Group #1 October 197.1 532.7 .66 .48 1.70 .28 .00 .47 November 287.6 595.7 .97 .70 1.07 .28 .00 .39 December 330.5 777.0 1.24 .72 1.35 .42 .00 .24 January 481.3 1180.2 2.90 1.18 1.45 .59 .02 .17 February 812.9 1064.8 2.55 2.27 .31 .11 .56 .76 March 1628.8 2023.8 1.18 1.13 .24 .05 .67 .91 April 2139.4 1851.4 .70 1.10 .13 .57 .58 .06 May 2863.4 2399.0 1.08 1.10 .16 .03 .81 .96 June 1332.4 1588.8 1.90 1.35 .19 .29 .73 .54 July 367.6 963.0 1.57 .44 1.62 .72 .00 .10 August 193.3 958.5 1.01 .40 3.96 .60 .00 .28 September 211.8 888.7 .74 .67 3.20 .10 .00 .82

Parameter Group #2 1-day minimum 69.1 114.0 1.22 .42 .65 .66 .00 .06 3-day minimum 69.5 154.0 1.23 1.06 1.21 .14 .00 .72 7-day minimum 70.7 281.4 1.13 .95 2.98 .16 .00 .60 30-day minimum 105.1 394.1 1.14 .61 2.75 .47 .00 .10 90-day minimum 183.3 585.1 .79 .51 2.19 .35 .00 .27 1-day maximum 7099.7 4730.0 2.25 2.73 .33 .22 .40 .54 3-day maximum 6099.7 3990.0 1.97 2.74 .35 .39 .28 .30 7-day maximum 4878.5 3940.0 1.61 1.91 .19 .18 .39 .54 30-day maximum 3544.7 3408.7 1.15 1.21 .04 .06 .85 .82 90-day maximum 2953.7 2835.4 .87 1.07 .04 .23 .85 .50 Number of zero days .0 .0 .00 .00 999999.00 999999.00 .00 .00 Base flow .1 .2 .62 1.16 .64 .89 .00 .17

Parameter Group #3 Date of minimum 275.0 305.0 .11 .14 .16 .30 .01 .51 Date of maximum 73.0 48.0 .20 .19 .14 .01 .22 .97

Parameter Group #4 Low pulse count 5.0 5.0 .60 1.80 .00 2.00 .49 .00 Low pulse duration 12.5 1.8 1.07 .93 .86 .13 .05 .78 High pulse count 5.0 11.0 .60 1.09 1.20 .82 .00 .06 High pulse duration 16.6 5.5 1.21 2.29 .67 .89 .19 .27 The low pulse threshold is 206.90 The high pulse level is 1471.20

Parameter Group #5 Rise rate 198.5 282.1 2.36 .74 .42 .69 .10 .05 Fall rate -128.6 -263.0 -2.02 -.59 1.05 .71 .00 .07 Number of reversals 128.0 187.0 .16 .16 .46 .03 .00 .94

04/21/04 Page 84 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Variance Data, Box and Whisker Format

October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

Pre-Impact Distribution 1-day min 42.2 117.5 86.0 111.1 167.7 187.2 413.9 516.6 200.4 76.7 28.2 44.9 24.2 24.4 25.3 28.2 38.2 25 pctile 120.3 195.3 253.1 275.9 445.6 837.4 1160.6 1004.3 342.9 159.4 74.3 106.8 52.1 52.4 56.0 63.5 101.7 Median 197.1 287.6 330.5 481.3 812.9 1628.8 2139.5 2863.5 1332.4 367.6 193.3 211.8 69.1 69.5 70.7 105.1 183.3 75 pctile 249.6 474.3 661.8 1670.1 2520.1 2765.6 2666.5 4084.3 2869.4 735.4 270.5 263.3 136.7 138.2 136.1 183.5 246.5 1-day max 1022.9 3910.2 5016.5 9484.0 9493.6 5286.0 4920.1 5533.5 6722.2 3064.4 776.3 484.7 243.8 247.0 256.5 428.0 548.0

Post-Impact Impact Di stribution 1-day min 204.3 106.2 320.0 188.3 124.7 123.9 255.1 294.7 228.1 88.2 141.5 205.9 15.0 15.0 19.9 45.3 131.8 25 pctile 404.4 365.4 524.7 554.0 656.2 726.0 878.3 859.7 582.6 760.8 722.5 541.8 108.0 111.0 129.3 291.2 331.2 Median 532.7 595.7 777.0 1180.2 1064.8 2023.8 1851.4 2399.0 1588.8 963.0 958.6 888.7 114.0 154.0 281.4 394.1 585.1 75 pctile 657.5 784.4 1082.6 1943.9 3078.2 3012.6 2921.7 3506.5 2731.3 1182.7 1107.6 1134.2 156.0 275.0 397.9 531.5 631.5 1-day max 934.9 3806.0 4632.6 9672.6 6612.9 5561.3 5381.7 6159.4 6496.0 3648.4 1719.0 1401.3 396.0 568.0 695.1 845.1 1120.1

1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

Pre-Impact Distribution 1-day min 746.6 703.0 677.9 588.1 432.8 0.0 0.0 223.0 2.0 0.0 0.0 0.0 0.0 21.4 -593.9 99.0 25 pctile 2956.0 2446.5 1722.7 1441.0 1174.1 0.0 0.1 238.0 44.0 4.0 4.4 4.0 3.5 76.9 -306.1 114.0 Median 7099.7 6099.7 4878.5 3544.7 2953.7 0.0 0.1 275.0 73.0 5.0 12.5 5.0 16.6 198.5 -128.6 128.0 75 pctile 18906.8 14478.4 9585.3 5505.5 3730.3 0.0 0.1 278.0 116.0 7.0 17.8 7.0 23.6 545.4 -46.8 134.0 1-day max 75832.0 52347.5 29219.6 11441.8 5508.7 0.0 0.2 287.0 360.0 13.0 34.0 11.0 36.0 1060.8 -17.3 151.0

Post-Impact Distribution 1-day min 1210.0 913.0 500.0 410.2 331.1 0.0 0.0 6.0 2.0 0.0 0.0 0.0 0.0 133.5 -637.0 140.0 25 pctile 2580.0 1933.3 1372.7 1111.3 911.5 0.0 0.1 279.0 14.0 1.0 1.0 5.0 1.3 220.6 -371.3 178.0 Median 4730.0 3990.0 3940.0 3408.7 2835.4 0.0 0.2 305.0 48.0 5.0 1.8 11.0 5.5 282.1 -263.0 187.0 75 pctile 15500.0 12853.3 8890.0 5239.7 3934.7 0.0 0.4 331.0 85.0 10.0 2.7 17.0 13.8 429.8 -215.4 208.0 1-day max 57100.0 40300.0 24671.4 10351.0 5759.0 0.0 0.6 363.0 361.0 61.0 11.2 28.0 23.5 691.8 -121.8 229.0

04/21/04 Page 85 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

IHA Percentile Data

(3) Gage B - 4445 South Fork American River Near Placerville (Unregulated), April 2004 Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Pre-Impact Post-Impact 10% 25% 50% 75% 90% (75-25)/50 10% 25% 50% 75% 90% (75-25)/50

Parameter Group #1 October 94.62 120.33 197.11 249.62 451.80 .66 263.46 404.35 532.71 657.52 856.04 .48 November 139.46 195.25 287.58 474.27 1254.15 .97 238.54 365.40 595.73 784.37 1389.75 .70 December 146.66 253.05 330.54 661.82 2905.96 1.24 454.28 524.74 777.03 1082.58 2794.17 .72 January 187.40 275.93 481.29 1670.09 3558.22 2.90 414.59 553.97 1180.16 1943.94 3185.11 1.18 February 307.41 445.59 812.92 2520.13 4072.15 2.55 466.94 656.21 1064.75 3078.21 3906.29 2.27 March 586.24 837.38 1628.79 2765.56 4675.52 1.18 583.15 726.00 2023.81 3012.58 4575.81 1.13 April 714.80 1160.61 2139.45 2666.50 3125.02 .70 541.29 878.33 1851.40 2921.67 3899.73 1.10 May 657.63 1004.25 2863.45 4084.30 5393.40 1.08 630.84 859.74 2399.03 3506.45 5222.19 1.10 June 233.45 342.86 1332.39 2869.41 5019.93 1.90 416.77 582.57 1588.80 2731.33 5487.07 1.35 July 123.76 159.41 367.63 735.42 2414.14 1.57 396.36 760.84 963.00 1182.71 3178.65 .44 August 55.99 74.25 193.34 270.48 476.82 1.01 386.23 722.52 958.55 1107.61 1487.24 .40 September 84.36 106.83 211.80 263.26 386.48 .74 377.61 541.83 888.73 1134.17 1335.89 .67

Parameter Group #2 1-day minimum 43.64 52.10 69.10 136.70 182.40 1.22 83.80 108.00 114.00 156.00 324.80 .42 3-day minimum 45.97 52.43 69.53 138.17 183.90 1.23 86.60 111.00 154.00 275.00 393.07 1.06 7-day minimum 46.34 56.01 70.71 136.09 179.80 1.13 88.14 129.29 281.43 397.86 505.43 .95 30-day minimum 53.11 63.47 105.13 183.45 202.32 1.14 106.40 291.23 394.13 531.53 604.14 .61 90-day minimum 75.02 101.72 183.29 246.53 323.52 .79 241.00 331.20 585.06 631.52 862.39 .51 1-day maximum 1646.22 2956.00 7099.70 18906.80 43873.39 2.25 1490.00 2580.00 4730.00 15500.00 22999.99 2.73 3-day maximum 1440.95 2446.50 6099.67 14478.40 33282.28 1.97 1291.80 1933.33 3990.00 12853.33 18047.99 2.74 7-day maximum 1062.25 1722.66 4878.50 9585.33 19969.13 1.61 943.97 1372.71 3940.00 8890.00 11871.71 1.91 30-day maximum 921.88 1441.00 3544.70 5505.51 8358.73 1.15 779.01 1111.27 3408.67 5239.67 7167.60 1.21 90-day maximum 672.99 1174.13 2953.74 3730.33 5293.55 .87 687.45 911.50 2835.44 3934.67 5424.51 1.07 Number of zero days .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 Base flow .03 .06 .12 .14 .15 .62 .07 .13 .19 .35 .48 1.16

Parameter Group #3 Date of minimum 226.40 238.00 275.00 278.00 285.20 .11 258.20 279.00 305.00 331.00 15.40 .14 Date of maximum .40 44.00 73.00 116.00 139.20 .20 337.80 14.00 48.00 85.00 133.00 .19

Parameter Group #4 Low pulse count 2.60 4.00 5.00 7.00 8.20 .60 .00 1.00 5.00 10.00 16.60 1.80 Low pulse duration 2.44 4.40 12.50 17.75 29.60 1.07 .00 1.00 1.80 2.67 4.20 .93 High pulse count 1.00 4.00 5.00 7.00 9.20 .60 .80 5.00 11.00 17.00 23.00 1.09 High pulse duration 1.00 3.50 16.60 23.57 34.24 1.21 .80 1.25 5.50 13.82 18.14 2.29

Parameter Group #5 Rise rate 49.75 76.89 198.47 545.38 829.68 2.36 190.20 220.57 282.12 429.81 526.55 .74 Fall rate -405.52 -306.13 -128.61 -46.80 -34.83 -2.02 -454.94 -371.33 -263.03 -215.42 -182.15 -.59 Number of reversals 106.20 114.00 128.00 134.00 140.40 .16 157.80 178.00 187.00 208.00 217.00 .16

04/21/04 Page 86 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverAverage Near flow Placervillefor October (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1100 <>------<------>

1000

900

800

700 75th percen

600 median 500

400 25th percen Cubic Feet per Second 300

200

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 87 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverAverage Near flow forPlacerville November (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000 Cubic Feet per Second 1000 75th percen median

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 88 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Average flow for December Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

3000

2000 Cubic Feet per Second

75th percen 1000 median

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 89 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Average flow for January Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 10000 <>------<------>

9000

8000

7000

6000

5000

4000

Cubic Feet per Second 3000

75th percen 2000

median 1000 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 90 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Average flow for February Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 10000 <>------<------>

9000

8000

7000

6000

5000

4000

75th percen

Cubic Feet per Second 3000

2000

median 1000 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 91 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Average flow for March Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

75th percen 3000

median 2000 Cubic Feet per Second

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 92 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Average flow for April Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

3000 75th percen

2000 median Cubic Feet per Second

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 93 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Average flow for May Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7000 <>------<------>

6000

5000

4000 75th percen

3000

median

Cubic Feet per Second 2000

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 94 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Average flow for June Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7000 <>------<------>

6000

5000

4000

3000 75th percen

Cubic Feet per Second 2000 median

1000

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 95 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverAverage Near flow Placerville for July (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000

75th percen Cubic Feet per Second 1000 median

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 96 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverAverage Near flow Placervillefor August (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 2000 <>------<------>

1500

75th percen

1000 median

25th percen Cubic Feet per Second 500

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 97 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Average flow for September Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1600 <>------<------>

1400

1200 75th percen

1000 median

800

600 25th percen Cubic Feet per Second 400

200

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 98 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 1-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200

75th percen

Cubic Feet per Second median 100 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 99 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 3-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 600 <>------<------>

500

400

300 75th percen

200 Cubic Feet per Second median

100 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 100 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 7-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 700 <>------<------>

600

500

75th percen 400

300 median

Cubic Feet per Second 200

25th percen 100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 101 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 30-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 900 <>------<------>

800

700

600 75th percen 500

400 median

300

Cubic Feet per Second 25th percen

200

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 102 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 90-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1200 <>------<------>

1000

800

75th percen 600 median

400 Cubic Feet per Second 25th percen

200

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 103 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 1-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 80000 <>------<------>

70000

60000

50000

40000

30000 Cubic Feet per Second 20000 75th percen

10000 median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 104 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 3-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 60000 <>------<------>

50000

40000

30000

20000 Cubic Feet per Second

75th percen

10000

median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 105 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American River7-day Near maximum Placerville streamflow (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 30000 <>------<------>

25000

20000

15000

10000 75th percen Cubic Feet per Second

5000 median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 106 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American River30-day Near maximum Placerville streamflow (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 12000 <>------<------>

10000

8000

6000 75th percen

4000

Cubic Feet per Second median

2000

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 107 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000 75th percen

3000 median

2000 Cubic Feet per Second

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 108 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Zero streamflow days Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 109 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Base Flow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 0.6 <>------<------>

0.5

0.4 75th percen

0.3

0.2 median Cubic Feet per Second

25th percen 0.1

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 110 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Date of minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

75th percen

median 300

25th percen

200 Julian Day

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 111 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Date of maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Julian Day

100 75th percen

median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 112 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Low Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 70 <>------<------>

Number 30

75th percen 10 median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 113 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Low Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 Days

75th percen median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 114 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 High Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 30 <>------<------>

75th percen

15 Number

median 10

5 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 115 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverHigh Near Pulse PlacervilleDuration (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 Days

75th percen

median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 116 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American River NearRise RatePlacerville (Unregulated), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1200 <>------<------>

1000

800

600 CFS/Day 75th percen 400

median

200 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 117 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Fall Rate

0 1875Pre-Impact<>------Period 1901 Post-Impact < 1975------Period 2001 >

-100

-200 75th percen

median -300

25th percen CFS/Day -400

-500

-600

-700 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 118 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Unregulated), April 2004 Pre-Impact PeriodReversals Post-Impact Period

1875 1901 1975 2001 240 <>------<------>

220 75th percen

200

median 180 25th percen

160 Number

140

120

100

80 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.ann, P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.baw

04/21/04 Page 119 of 160 (3) Gage B - South Fork American River at Chili Bar Res. Proposed Proj 184/UARP (Unregulated) versus 4445 South Fork American River Near Placerville (Regulated)

B-4445 South Fork American River Near Placerville (Unregulated), April 2004

80000

70000

60000

50000

40000

30000 Cubic Feet per Second 20000

10000

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\3-GageB-Unreg\GB-U.dat

04/21/04 Page 120 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Errors

No Errors

04/21/04 Page 121 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

IHA Annual Summary Statistics

Year October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

1875 144.2 222.5 293.3 440.3 709.5 1307.3 1186.1 4326.8 3615.9 782.2 230.7 128.2 97.3 99.0 101.9 124.2 205.6 1876 428.0 441.7 335.2 300.5 329.5 501.4 752.7 1004.9 254.5 89.3 143.5 82.5 55.2 61.2 65.0 81.5 82.3 1877 81.1 84.8 86.1 152.7 177.3 205.9 504.8 639.3 446.8 64.6 19.5 27.6 13.1 13.7 16.4 18.0 23.5 1878 24.6 117.3 728.4 1703.9 1125.0 2310.0 2569.9 3576.9 2856.4 767.1 212.0 252.2 18.6 19.7 20.4 24.3 193.2 1879 145.4 222.5 293.3 440.3 709.5 1307.3 1186.1 4326.8 3615.9 782.2 230.7 128.2 97.3 92.2 87.6 106.5 181.8 1880 196.6 373.5 419.2 5359.9 3801.7 1631.9 2325.0 3144.1 2327.6 1052.7 213.3 135.6 80.4 83.3 86.4 110.8 131.1 1881 112.3 148.6 258.7 327.7 608.3 851.5 1683.4 1579.3 489.0 113.3 65.1 61.7 47.2 49.4 54.2 58.4 74.1 1882 152.8 1868.7 2693.5 1441.2 5034.3 2744.8 5025.8 5510.5 3001.4 1007.0 327.3 430.9 65.0 74.0 96.7 149.6 367.1 1883 992.3 1101.5 2152.7 1657.5 3346.2 5202.3 2992.5 5542.9 6835.4 3122.2 826.8 411.1 245.4 247.9 249.4 311.6 491.8 1884 349.9 3921.7 4949.9 2051.5 1437.1 1848.0 1749.9 3259.1 1789.4 495.7 175.8 131.0 102.3 107.8 125.9 131.0 173.5 1885 224.1 807.7 497.2 405.6 555.2 770.1 2446.3 1918.2 638.9 144.9 95.9 141.7 78.8 79.8 83.1 93.7 120.5 1886 152.5 289.3 655.8 1444.9 9367.4 4674.6 2529.6 2964.0 1885.7 460.0 162.1 166.3 101.0 102.6 110.6 122.5 163.9 1887 192.1 152.9 154.7 221.1 559.1 805.6 1375.9 1077.9 289.2 90.1 51.6 54.0 42.4 44.2 46.8 49.0 57.2 1888 79.0 127.0 319.5 482.0 411.5 662.7 885.1 805.9 406.6 82.4 49.5 52.0 36.1 36.6 37.9 43.0 51.8 1889 55.0 284.0 266.9 269.7 461.7 3194.9 2884.3 2132.1 1220.5 225.9 92.3 131.6 43.5 44.1 46.2 54.7 109.7 1890 214.9 271.1 221.9 435.4 424.3 1049.6 1669.1 1170.3 741.7 158.1 70.8 61.9 47.0 49.1 50.8 58.7 65.8 1891 66.5 88.4 106.1 114.6 170.9 1113.1 1239.5 1891.8 1231.6 265.3 100.7 67.6 51.3 52.0 53.3 58.5 83.1 1892 126.1 202.7 172.3 200.3 824.8 867.3 1441.1 738.1 244.6 145.8 54.1 35.6 31.5 31.8 32.5 35.6 47.7 1893 86.1 117.5 482.8 1660.5 1322.9 2958.9 2971.2 4184.5 2590.5 745.9 229.8 122.0 41.7 42.9 43.1 79.3 129.5 1894 129.4 149.1 240.2 242.7 419.2 772.2 1099.2 1154.3 344.5 91.0 50.8 54.6 41.5 43.2 44.5 47.7 57.3 1895 73.0 292.9 542.4 3102.7 1486.6 4697.6 3647.4 5683.9 5114.0 2712.2 638.8 252.4 44.9 48.5 56.7 72.2 201.6 1896 164.4 203.1 866.7 1391.7 3614.9 2664.8 3140.2 4689.2 1955.1 586.6 214.0 156.1 134.2 135.9 130.5 137.9 158.2 1897 154.3 881.6 3933.7 9404.5 2017.3 1916.0 2445.2 2833.6 1403.1 349.3 156.8 116.7 99.7 102.4 105.6 113.1 133.8 1898 144.8 244.7 317.2 1924.4 2506.0 2865.5 2968.1 3964.2 5975.2 2411.7 419.1 288.7 101.2 103.9 110.8 144.4 234.7 1899 211.3 456.7 638.7 1554.9 3123.7 2018.3 2413.5 4408.0 3003.2 669.0 296.5 175.8 151.0 145.6 136.8 136.6 176.6 1900 155.0 237.0 224.6 1231.3 2433.0 1815.0 2556.8 3270.7 1216.2 270.4 138.1 131.6 104.4 95.7 92.7 109.4 137.7 1901 169.5 206.8 259.1 266.8 452.7 1038.8 1430.3 1897.7 281.1 100.7 64.1 69.6 47.9 48.4 49.9 59.0 77.0 1975 591.6 706.5 992.9 1180.2 1064.8 1406.1 1874.0 3506.5 2784.8 1182.6 1041.4 1054.3 114.0 371.0 505.4 531.5 756.3 1976 579.4 784.4 1105.0 748.7 647.7 530.6 522.2 733.7 492.6 938.5 958.6 576.6 108.0 109.3 246.6 407.6 331.2 1977 400.9 271.3 320.0 188.3 124.7 123.9 255.1 294.7 228.1 88.2 141.5 244.0 15.0 15.0 19.9 45.3 131.8 1978 275.3 106.2 485.3 1340.7 887.8 2023.8 2833.3 3367.4 2226.1 986.3 736.5 541.8 27.0 29.0 30.4 102.5 264.0 1979 593.6 706.5 992.9 1180.2 1064.8 1406.1 1874.0 3506.5 2784.8 1182.6 1041.4 1054.3 114.0 371.0 505.4 572.5 613.5 1980 588.0 477.0 798.8 4027.5 3299.7 2343.2 2706.3 3075.2 1964.4 1584.5 965.3 1327.6 109.0 119.3 281.4 443.0 604.1 1981 657.5 638.6 885.0 760.2 810.0 993.2 987.6 907.7 583.1 849.5 841.9 758.5 98.0 127.3 293.9 426.2 609.6 1982 430.6 1275.5 2330.6 2388.7 4370.0 3413.9 5381.7 5166.8 3511.0 1723.1 1310.6 1134.2 110.0 111.0 200.0 394.1 1058.4 1983 877.9 1846.8 2601.9 2221.0 3790.4 5561.3 4278.7 5443.9 6496.0 3648.4 1483.4 1122.6 324.0 397.3 456.0 845.1 1120.1 1984 934.9 3806.0 4632.6 2974.5 2209.0 2363.6 2491.0 2410.0 1482.7 866.5 1107.6 1003.5 396.0 568.0 695.1 658.3 813.4 1985 645.9 942.8 842.0 743.7 1318.4 1017.8 1533.3 1231.7 582.6 963.0 917.6 888.7 250.0 339.0 419.3 455.3 585.1 1986 452.9 452.8 1082.6 1461.2 6612.9 5067.4 2993.3 3074.5 2686.0 1182.7 1078.9 1052.3 125.0 135.0 273.1 376.3 629.9 1987 522.9 639.2 729.0 409.6 846.4 646.8 878.3 859.7 774.2 760.8 722.5 447.4 108.0 152.0 334.9 223.5 198.1 1988 204.3 107.4 464.2 554.0 743.3 650.3 546.1 474.3 432.6 409.3 408.2 453.9 101.0 101.0 102.6 107.4 251.7 1989 216.3 290.8 414.7 415.8 539.1 2329.5 1836.4 1258.2 1059.4 1012.1 1021.6 948.3 107.0 118.0 121.9 184.4 304.6 1990 306.2 323.2 499.2 582.6 592.4 869.7 930.8 772.9 666.8 932.8 916.9 680.4 98.0 110.7 127.7 291.2 373.2 1991 516.2 498.2 524.7 426.1 425.1 862.5 874.0 1103.1 811.2 622.8 712.0 721.8 114.0 154.0 325.3 379.0 450.0 1992 532.7 360.8 527.9 568.2 822.2 661.7 873.6 670.0 457.2 456.7 521.4 411.0 111.0 111.0 111.7 330.7 386.0 1993 388.3 373.4 631.5 1609.4 1369.0 2552.6 2712.7 3371.9 2731.3 1175.5 985.2 843.6 133.0 207.7 232.4 356.0 464.0 1994 480.6 581.3 702.8 506.8 656.2 596.3 733.0 716.4 531.6 460.4 459.9 462.2 165.0 243.0 334.3 430.4 423.4 1995 443.3 365.4 465.7 2743.8 1971.8 4452.9 3805.0 6159.4 5547.3 3240.3 1387.2 1401.3 156.0 160.3 160.9 365.4 422.6 1996 850.6 595.7 738.4 1214.9 2811.8 3121.0 3142.0 4824.8 2151.1 953.4 831.7 865.0 328.0 392.0 482.7 540.4 697.4 1997 740.1 812.0 3563.1 9672.6 3550.4 2649.7 1831.7 1814.8 1698.0 912.4 915.5 1260.3 198.0 230.3 284.3 590.6 631.5 1998 694.2 489.8 667.4 1943.9 3078.2 3161.3 3338.3 3728.1 5472.0 3163.2 1719.0 1369.0 145.0 177.7 397.9 466.6 603.9 1999 554.4 657.3 1071.5 1240.8 3261.4 3012.6 2921.7 3515.5 2536.0 1242.7 1502.7 1164.6 154.0 275.0 354.1 553.7 742.9 2000 677.7 711.5 777.0 1148.2 2242.2 2124.7 1851.4 2399.0 1588.8 1037.1 1371.5 1196.7 154.0 186.7 238.7 324.7 622.4 2001 404.4 1092.9 1217.9 543.1 477.4 726.0 943.7 1072.9 353.3 344.7 298.2 205.9 128.0 129.0 129.3 205.9 273.0

04/21/04 Page 122 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

IHA Annual Summary Statistics (Cont)

Year 1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

1875 6857.0 6538.6 6158.4 5430.3 3126.1 0.0 0.1 268.0 152.0 4.0 14.3 2.0 36.0 170.6 -109.3 139.0 1876 3199.3 1722.9 1389.7 1181.1 762.5 0.0 0.2 210.0 300.0 5.0 18.6 1.0 1.0 66.2 -41.3 140.0 1877 968.3 930.7 899.1 766.1 542.8 0.0 0.1 259.0 152.0 9.0 25.7 0.0 0.0 24.9 -19.5 148.0 1878 5406.6 4782.8 4260.4 3823.0 3126.5 0.0 0.0 285.0 116.0 3.0 9.7 10.0 13.9 267.4 -162.2 118.0 1879 6857.0 6538.6 6158.4 5430.3 3126.1 0.0 0.1 268.0 152.0 4.0 13.0 2.0 36.0 171.8 -108.9 140.0 1880 42569.1 30783.0 18079.6 5560.3 3640.6 0.0 0.1 280.0 13.0 4.0 8.5 5.0 26.6 573.5 -313.4 105.0 1881 3426.9 3193.5 2761.5 2019.1 1484.7 0.0 0.1 268.0 115.0 4.0 27.3 7.0 4.1 89.9 -56.6 144.0 1882 39693.7 24460.3 14140.9 6402.2 4924.3 0.0 0.0 275.0 47.0 3.0 6.0 5.0 35.0 955.6 -442.8 109.0 1883 23371.8 14122.1 9934.0 8066.9 5446.5 0.0 0.1 291.0 73.0 0.0 0.0 7.0 29.6 719.7 -370.7 117.0 1884 18561.8 16771.1 11906.9 5350.1 3709.7 0.0 0.1 271.0 360.0 2.0 21.5 8.0 20.9 612.0 -290.5 109.0 1885 4099.3 3909.9 3515.3 2628.5 1768.2 0.0 0.1 239.0 106.0 5.0 16.6 5.0 11.2 92.0 -63.0 128.0 1886 51122.6 45028.2 28058.9 11329.8 5551.9 0.0 0.1 278.0 48.0 7.0 8.0 7.0 20.1 718.1 -415.5 109.0 1887 4010.6 2188.8 1875.5 1562.5 1101.7 0.0 0.1 274.0 44.0 9.0 17.6 6.0 3.3 75.2 -46.9 124.0 1888 1569.5 1090.5 1047.0 902.9 785.3 0.0 0.1 250.0 5.0 4.0 27.5 1.0 1.0 51.7 -40.7 146.0 1889 7350.7 5878.1 4892.4 3561.5 2778.7 0.0 0.1 276.0 68.0 6.0 12.2 6.0 14.5 194.2 -133.9 137.0 1890 2408.6 2044.0 1856.4 1669.1 1336.8 0.0 0.1 253.0 114.0 3.0 26.3 8.0 3.9 86.3 -52.7 115.0 1891 8688.2 4631.7 2556.3 2035.4 1491.9 0.0 0.1 279.0 64.0 4.0 20.5 6.0 6.3 132.8 -85.3 124.0 1892 3151.0 2469.8 1756.3 1441.1 1158.2 0.0 0.1 273.0 51.0 7.0 15.4 6.0 1.8 79.2 -50.7 141.0 1893 7835.4 6172.7 4838.6 4215.8 3674.5 0.0 0.0 286.0 77.0 3.0 23.3 9.0 14.6 332.3 -185.7 119.0 1894 2006.4 1920.8 1727.5 1377.3 1016.5 0.0 0.1 251.0 110.0 4.0 34.8 2.0 5.0 52.5 -34.3 140.0 1895 19901.5 14881.2 10920.3 5904.3 5025.3 0.0 0.0 276.0 122.0 3.0 1.7 5.0 35.6 577.4 -369.2 110.0 1896 16406.5 13127.4 8942.7 4938.9 3570.5 0.0 0.1 274.0 137.0 6.0 6.2 6.0 24.5 514.2 -262.6 134.0 1897 75667.0 52157.8 29083.6 10315.7 5255.0 0.0 0.1 268.0 2.0 4.0 16.3 9.0 17.6 997.3 -618.4 139.0 1898 16230.4 10567.4 7191.8 5975.2 4511.6 0.0 0.1 275.0 84.0 2.0 14.5 6.0 27.0 454.5 -307.4 165.0 1899 12140.9 9015.9 6605.3 4601.7 3312.0 0.0 0.1 253.0 40.0 1.0 2.0 11.0 12.8 380.3 -249.1 150.0 1900 12558.0 7664.4 4851.9 3334.1 2596.1 0.0 0.1 274.0 45.0 5.0 12.6 9.0 13.2 330.7 -202.1 136.0 1901 3146.3 2963.3 2819.9 2323.4 1480.7 0.0 0.1 252.0 129.0 4.0 27.5 4.0 9.8 81.9 -52.8 136.0 1975 4020.0 3946.7 3940.0 3820.0 2835.4 0.0 0.4 302.0 85.0 1.0 1.0 18.0 5.5 270.8 -260.9 182.0 1976 3010.0 1495.3 1191.4 1111.3 911.5 0.0 0.3 290.0 301.0 1.0 4.0 1.0 1.0 202.0 -197.3 204.0 1977 1290.0 913.0 500.0 410.2 331.1 0.0 0.1 247.0 291.0 60.0 3.6 0.0 0.0 239.5 -215.4 158.0 1978 4730.0 4196.7 4014.3 3595.7 2920.0 0.0 0.0 331.0 17.0 15.0 3.9 14.0 9.1 328.0 -281.5 176.0 1979 4020.0 3946.7 3940.0 3820.0 2835.4 0.0 0.4 302.0 85.0 1.0 1.0 18.0 5.5 270.4 -260.9 182.0 1980 19300.0 15876.7 10504.3 4342.3 3348.2 0.0 0.2 289.0 14.0 4.0 1.8 17.0 11.7 429.8 -419.9 177.0 1981 3630.0 2413.3 1599.9 1155.9 1285.9 0.0 0.4 25.0 86.0 3.0 1.7 5.0 2.2 260.3 -255.3 181.0 1982 21700.0 14510.0 9117.1 5896.7 4875.1 0.0 0.1 305.0 47.0 3.0 2.7 15.0 15.3 563.7 -488.9 157.0 1983 15800.0 10810.0 7755.7 6826.3 5542.1 0.0 0.1 282.0 73.0 0.0 0.0 11.0 25.6 517.3 -370.5 140.0 1984 15500.0 12853.3 9974.3 5239.7 3934.7 0.0 0.3 165.0 361.0 0.0 0.0 15.0 14.2 471.7 -446.5 195.0 1985 3420.0 2563.3 2114.3 1575.0 1332.0 0.0 0.4 317.0 39.0 0.0 0.0 10.0 3.1 200.7 -191.1 199.0 1986 28200.0 26733.3 17341.4 8532.7 4975.8 0.0 0.1 310.0 48.0 5.0 1.6 7.0 22.1 491.2 -405.9 168.0 1987 2010.0 1730.0 1265.1 999.1 846.3 0.0 0.5 261.0 73.0 8.0 1.4 2.0 2.0 200.8 -204.5 216.0 1988 1540.0 1356.7 956.6 764.5 669.8 0.0 0.2 325.0 350.0 7.0 9.4 0.0 0.0 133.5 -121.8 185.0 1989 5420.0 3990.0 3528.6 2601.7 1833.4 0.0 0.1 13.0 85.0 16.0 2.3 11.0 5.4 282.1 -293.4 208.0 1990 1790.0 1463.3 1345.7 975.0 863.7 0.0 0.2 29.0 219.0 12.0 2.8 3.0 1.0 224.0 -241.8 208.0 1991 2950.0 2152.0 1372.7 1164.2 961.9 0.0 0.5 283.0 65.0 4.0 1.5 2.0 1.5 220.6 -218.6 216.0 1992 2580.0 1933.3 1486.1 931.4 834.8 0.0 0.2 308.0 52.0 15.0 2.2 3.0 1.3 203.3 -198.9 229.0 1993 6330.0 5176.7 3832.9 3408.7 3099.8 0.0 0.2 279.0 22.0 2.0 1.5 9.0 15.9 285.3 -263.0 202.0 1994 1210.0 1032.3 893.6 782.6 691.9 0.0 0.6 278.0 132.0 0.0 0.0 0.0 0.0 148.3 -146.2 221.0 1995 14800.0 13066.7 9830.0 6201.3 5395.1 0.0 0.1 363.0 123.0 4.0 3.3 15.0 15.2 438.1 -398.4 178.0 1996 16900.0 13400.0 8890.0 4883.7 3745.8 0.0 0.3 6.0 137.0 0.0 0.0 10.0 14.7 390.7 -325.7 185.0 1997 57100.0 40300.0 24671.4 10351.0 5759.0 0.0 0.1 313.0 2.0 0.0 0.0 19.0 9.3 691.8 -637.0 183.0 1998 7260.0 6690.0 6531.4 5647.7 4342.2 0.0 0.2 324.0 85.0 2.0 1.0 13.0 17.3 386.3 -331.1 203.0 1999 8510.0 5873.3 4430.0 3701.0 3141.9 0.0 0.2 275.0 40.0 1.0 0.0 15.0 12.1 386.9 -371.3 208.0 2000 6480.0 5450.0 4035.7 2727.7 2234.0 0.0 0.2 9.0 45.0 2.0 1.0 25.0 5.9 362.5 -370.9 187.0 2001 2330.0 1973.3 1614.3 1278.2 973.5 0.0 0.2 268.0 347.0 14.0 3.1 10.0 1.9 245.7 -231.7 187.0

04/21/04 Page 123 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Non-Parametric IHA Scorecard

(4) Gage B - 4445 South Fork American River Near Placerville (Natural), April 2004

Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Watershed area 1.00 Mean annual flow 1219.74 1432.95 Mean flow/area 1219.74 1432.95 Annual C. V. .93 .58 Flow predictability .39 .42 Constancy/predictability .43 .71 % of floods in 60d period .42 .42 flood-free season 59.00 18.00

MEDIANS COEFF. of DISP. DEVIATION FACTOR SIGNIFICANCE COUNT Pre Post Pre Post Medians C.V. Medians C.V. Parameter Group #1 October 152.5 532.7 .72 .48 2.49 .34 .00 .55 November 237.0 595.7 1.23 .70 1.51 .43 .00 .18 December 319.5 777.0 1.30 .72 1.43 .45 .00 .22 January 482.0 1180.2 2.89 1.18 1.45 .59 .04 .17 February 824.8 1064.8 2.49 2.27 .29 .09 .61 .78 March 1631.9 2023.8 1.16 1.13 .24 .03 .65 .95 April 2325.0 1851.4 .71 1.10 .20 .56 .52 .08 May 2964.0 2399.0 1.06 1.10 .19 .04 .75 .93 June 1403.1 1588.8 1.82 1.35 .13 .26 .81 .51 July 349.2 963.0 1.92 .44 1.76 .77 .00 .10 August 156.8 958.5 1.06 .40 5.11 .62 .00 .31 September 128.2 888.7 .81 .67 5.93 .18 .00 .78

Parameter Group #2 1-day minimum 55.2 114.0 1.06 .42 1.07 .60 .00 .08 3-day minimum 61.2 154.0 .95 1.06 1.52 .12 .00 .84 7-day minimum 65.0 281.4 .91 .95 3.33 .04 .00 .86 30-day minimum 81.5 394.1 .85 .61 3.84 .28 .00 .50 90-day minimum 131.1 585.1 .82 .51 3.46 .37 .00 .30 1-day maximum 7350.7 4730.0 2.09 2.73 .36 .31 .37 .39 3-day maximum 6172.7 3990.0 1.89 2.74 .35 .45 .31 .24 7-day maximum 4851.9 3940.0 1.66 1.91 .19 .15 .39 .61 30-day maximum 3823.0 3408.7 1.02 1.21 .11 .19 .59 .49 90-day maximum 3126.1 2835.4 .76 1.07 .09 .40 .68 .28 Number of zero days .0 .0 .00 .00 999999.00 999999.00 .00 .00 Base flow .1 .2 .61 1.16 1.37 .89 .00 .10

Parameter Group #3 Date of minimum 273.0 305.0 .06 .14 .17 1.26 .00 .05 Date of maximum 73.0 48.0 .20 .19 .14 .01 .21 .98

Parameter Group #4 Low pulse count 4.0 3.0 .50 2.33 .25 3.67 .12 .00 Low pulse duration 15.4 1.5 .96 1.83 .90 .91 .20 .21 High pulse count 6.0 10.0 .67 1.20 .67 .80 .01 .08 High pulse duration 13.9 5.5 1.62 2.40 .60 .49 .20 .34 The low pulse threshold is 163.90 The high pulse level is 1551.30

Parameter Group #5 Rise rate 194.2 282.1 2.53 .74 .45 .71 .08 .06 Fall rate -133.9 -263.0 -1.90 -.59 .96 .69 .00 .07 Number of reversals 136.0 187.0 .17 .16 .38 .05 .00 .87

04/21/04 Page 124 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Variance Data, Box and Whisker Format

October November December January February March April May June July August September 1-day min 3-day min 7-day min 30-day min 90-day min

Pre-Impact Distribution 1-day min 24.6 84.8 86.1 114.6 170.9 205.9 504.8 639.3 244.6 64.6 19.5 27.6 13.1 13.7 16.4 18.0 23.5 25 pctile 86.1 149.1 240.2 269.7 452.7 851.5 1239.5 1170.3 446.8 113.3 65.1 61.9 42.4 44.1 46.2 54.7 74.1 Median 152.5 237.0 319.5 482.0 824.8 1631.9 2325.0 2964.0 1403.1 349.3 156.8 128.2 55.2 61.2 65.0 81.5 131.1 75 pctile 196.6 441.7 655.8 1660.5 2506.0 2744.8 2884.3 4326.8 3001.4 782.2 230.7 166.3 101.0 102.4 105.6 124.2 181.8 1-day max 992.3 3921.7 4949.9 9404.5 9367.4 5202.3 5025.8 5683.9 6835.4 3122.2 826.8 430.9 245.4 247.9 249.4 311.6 491.8

Post-Impact Distribution 1-day min 204.3 106.2 320.0 188.3 124.7 123.9 255.1 294.7 228.1 88.2 141.5 205.9 15.0 15.0 19.9 45.3 131.8 25 pctile 404.4 365.4 524.7 554.0 656.2 726.0 878.3 859.7 582.6 760.8 722.5 541.8 108.0 111.0 129.3 291.2 331.2 Median 532.7 595.7 777.0 1180.2 1064.8 2023.8 1851.4 2399.0 1588.8 963.0 958.6 888.7 114.0 154.0 281.4 394.1 585.1 75 pctile 657.5 784.4 1082.6 1943.9 3078.2 3012.6 2921.7 3506.5 2731.3 1182.7 1107.6 1134.2 156.0 275.0 397.9 531.5 631.5 1-day max 934.9 3806.0 4632.6 9672.6 6612.9 5561.3 5381.7 6159.4 6496.0 3648.4 1719.0 1401.3 396.0 568.0 695.1 845.1 1120.1

1-day max 3-day max 7-day max 30-day max 90-day max Zero days Base flow Date min Date max Lo pulse #Lo pulse LHi pulse #Hi pulse LRise rate Fall rate Reversals

Pre-Impact Distribution 1-day min 968.3 930.7 899.1 766.1 542.8 0.0 0.0 210.0 2.0 0.0 0.0 0.0 0.0 24.9 -618.4 105.0 25 pctile 3199.3 2469.8 1875.5 1669.1 1336.8 0.0 0.1 253.0 44.0 3.0 8.5 4.0 4.1 81.9 -307.4 117.0 Median 7350.7 6172.7 4851.9 3823.0 3126.1 0.0 0.1 273.0 73.0 4.0 15.4 6.0 13.9 194.2 -133.9 136.0 75 pctile 18561.8 14122.1 9934.0 5560.3 3709.7 0.0 0.1 276.0 116.0 5.0 23.3 8.0 26.6 573.5 -52.7 140.0 1-day max 75667.0 52157.8 29083.6 11329.8 5551.9 0.0 0.2 291.0 360.0 9.0 34.8 11.0 36.0 997.3 -19.5 165.0

Post-Impact Distribution 1-day min 1210.0 913.0 500.0 410.2 331.1 0.0 0.0 6.0 2.0 0.0 0.0 0.0 0.0 133.5 -637.0 140.0 25 pctile 2580.0 1933.3 1372.7 1111.3 911.5 0.0 0.1 279.0 14.0 1.0 0.0 3.0 1.5 220.6 -371.3 178.0 Median 4730.0 3990.0 3940.0 3408.7 2835.4 0.0 0.2 305.0 48.0 3.0 1.5 10.0 5.5 282.1 -263.0 187.0 75 pctile 15500.0 12853.3 8890.0 5239.7 3934.7 0.0 0.4 331.0 85.0 8.0 2.8 15.0 14.7 429.8 -215.4 208.0 1-day max 57100.0 40300.0 24671.4 10351.0 5759.0 0.0 0.6 363.0 361.0 60.0 9.4 25.0 25.6 691.8 -121.8 229.0

04/21/04 Page 125 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

IHA Percentile Data

(4) Gage B - 4445 South Fork American River Near Placerville (Natural), April 2004 Pre-impact period: 1875-1901 (27 years) Post-impact period: 1975-2001 (27 years)

Pre-Impact Post-Impact 10% 25% 50% 75% 90% (75-25)/50 10% 25% 50% 75% 90% (75-25)/50

Parameter Group #1 October 64.21 86.10 152.48 196.56 365.49 .72 263.46 404.35 532.71 657.52 856.04 .48 November 111.50 149.10 237.01 441.70 1254.92 1.23 238.54 365.40 595.73 784.37 1389.75 .70 December 144.94 240.15 319.51 655.79 2941.53 1.30 454.28 524.74 777.03 1082.58 2794.17 .72 January 190.74 269.70 482.00 1660.51 3554.13 2.89 414.59 553.97 1180.16 1943.94 3185.11 1.18 February 299.08 452.67 824.82 2505.99 4048.19 2.49 466.94 656.21 1064.75 3078.21 3906.29 2.27 March 630.40 851.45 1631.85 2744.75 4679.19 1.16 583.15 726.00 2023.81 3012.58 4575.81 1.13 April 858.62 1239.53 2325.02 2884.33 3241.60 .71 541.29 878.33 1851.40 2921.67 3899.73 1.10 May 792.31 1170.34 2963.96 4326.75 5516.97 1.06 630.84 859.74 2399.03 3506.45 5222.19 1.10 June 275.81 446.84 1403.09 3001.39 5286.25 1.82 416.77 582.57 1588.80 2731.33 5487.07 1.35 July 87.93 113.25 349.25 782.19 2471.80 1.92 396.36 760.84 963.00 1182.71 3178.65 .44 August 50.56 65.05 156.79 230.71 463.03 1.06 386.23 722.52 958.55 1107.61 1487.24 .40 September 48.75 61.89 128.24 166.33 313.16 .81 377.61 541.83 888.73 1134.17 1335.89 .67

Parameter Group #2 1-day minimum 28.92 42.40 55.20 101.00 137.56 1.06 83.80 108.00 114.00 156.00 324.80 .42 3-day minimum 29.41 44.10 61.20 102.40 137.87 .95 86.60 111.00 154.00 275.00 393.07 1.06 7-day minimum 30.10 46.16 64.97 105.59 131.72 .91 88.14 129.29 281.43 397.86 505.43 .95 30-day minimum 33.30 54.67 81.51 124.16 145.46 .85 106.40 291.23 394.13 531.53 604.14 .61 90-day minimum 50.98 74.05 131.13 181.75 261.16 .82 241.00 331.20 585.06 631.52 862.39 .51 1-day maximum 1919.02 3199.30 7350.70 18561.80 44279.79 2.09 1490.00 2580.00 4730.00 15500.00 22999.99 2.73 3-day maximum 1596.42 2469.83 6172.73 14122.07 33632.02 1.89 1291.80 1933.33 3990.00 12853.33 18047.99 2.74 7-day maximum 1321.14 1875.54 4851.86 9934.04 20075.47 1.66 943.97 1372.71 3940.00 8890.00 11871.71 1.91 30-day maximum 1125.47 1669.10 3823.04 5560.27 8516.62 1.02 779.01 1111.27 3408.67 5239.67 7167.60 1.21 90-day maximum 780.74 1336.76 3126.07 3709.72 5293.32 .76 687.45 911.50 2835.44 3934.67 5424.51 1.07 Number of zero days .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 Base flow .03 .05 .08 .10 .11 .61 .07 .13 .19 .35 .48 1.16

Parameter Group #3 Date of minimum 247.80 253.00 273.00 276.00 285.20 .06 258.20 279.00 305.00 331.00 15.40 .14 Date of maximum .40 44.00 73.00 116.00 152.00 .20 337.80 14.00 48.00 85.00 133.00 .19

Parameter Group #4 Low pulse count 1.80 3.00 4.00 5.00 7.40 .50 .00 1.00 3.00 8.00 15.20 2.33 Low pulse duration 1.93 8.50 15.43 23.33 27.50 .96 .00 .00 1.50 2.75 3.95 1.83 High pulse count 1.00 4.00 6.00 8.00 9.20 .67 .00 3.00 10.00 15.00 18.20 1.20 High pulse duration 1.00 4.14 13.90 26.60 35.68 1.62 .00 1.50 5.50 14.70 18.27 2.40

Parameter Group #5 Rise rate 52.33 81.85 194.19 573.53 766.89 2.53 190.20 220.57 282.12 429.81 526.55 .74 Fall rate -420.96 -307.36 -133.94 -52.66 -39.42 -1.90 -454.94 -371.33 -263.03 -215.42 -182.15 -.59 Number of reversals 109.00 117.00 136.00 140.00 148.40 .17 157.80 178.00 187.00 208.00 217.00 .16

04/21/04 Page 126 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for October Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1000 <>------<------>

900

800

700 75th percen

600 median 500

400 25th percen

Cubic Feet per Second 300

200

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 127 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverAverage flowNear for PlacervilleNovember (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000 Cubic Feet per Second 1000 75th percen median

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 128 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for December Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 5000 <>------<------>

4000

3000

2000 Cubic Feet per Second

75th percen 1000 median

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 129 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for January Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 10000 <>------<------>

9000

8000

7000

6000

5000

4000

Cubic Feet per Second 3000

75th percen 2000

median 1000 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 130 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for February Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 10000 <>------<------>

9000

8000

7000

6000

5000

4000

75th percen

Cubic Feet per Second 3000

2000

median 1000 25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 131 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for March Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

75th percen 3000

median 2000 Cubic Feet per Second

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 132 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for April Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000

3000 75th percen

2000 median Cubic Feet per Second

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 133 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for May Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7000 <>------<------>

6000

5000

4000 75th percen

3000

median

Cubic Feet per Second 2000

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 134 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for June Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 7000 <>------<------>

6000

5000

4000

3000 75th percen

Cubic Feet per Second 2000 median

1000

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 135 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverAverage Near flow forPlacerville July (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 4000 <>------<------>

3000

2000

75th percen Cubic Feet per Second 1000 median

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 136 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverAverage Nearflow for Placerville August (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 2000 <>------<------>

1500

75th percen

1000 median

25th percen Cubic Feet per Second 500

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 137 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Average flow for September Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1600 <>------<------>

1400

1200 75th percen

1000 median

800

600 25th percen Cubic Feet per Second 400

200

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 138 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 1-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200

75th percen

Cubic Feet per Second median 100 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 139 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 3-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 600 <>------<------>

500

400

300 75th percen

200 Cubic Feet per Second median

100 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 140 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 7-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 700 <>------<------>

600

500

75th percen 400

300 median

Cubic Feet per Second 200

25th percen 100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 141 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 30-day minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 900 <>------<------>

800

700

600 75th percen 500

400 median

300

Cubic Feet per Second 25th percen

200

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 142 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000 75th percen

3000 median

2000 Cubic Feet per Second

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 143 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 1-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 80000 <>------<------>

70000

60000

50000

40000

30000 Cubic Feet per Second 20000 75th percen

10000 median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 144 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 3-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 60000 <>------<------>

50000

40000

30000

20000 Cubic Feet per Second

75th percen

10000

median

0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 145 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American River7-day maximum Near streamflow Placerville (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 30000 <>------<------>

25000

20000

15000

10000 75th percen Cubic Feet per Second

5000 median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 146 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American River30-day maximumNear streamflowPlacerville (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 12000 <>------<------>

10000

8000

6000 75th percen

4000

Cubic Feet per Second median

2000

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 147 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 90-day maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 6000 <>------<------>

5000

4000 75th percen

3000 median

2000 Cubic Feet per Second

1000 25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 148 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Zero streamflow days Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 11 <>------<------>

Number 5

75th percen 0 median 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 149 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Base Flow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 0.6 <>------<------>

0.5

0.4 75th percen

0.3

0.2 median Cubic Feet per Second

25th percen 0.1

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 150 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Date of minimum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

75th percen

median 300

25th percen

200 Julian Day

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 151 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Date of maximum streamflow Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 400 <>------<------>

300

200 Julian Day

100 75th percen

median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 152 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Low Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 70 <>------<------>

Number 30

10 75th percen

median 0 25th percen 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 153 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Low Pulse Duration Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 Days

75th percen median 0 1860 1880 1900 1920 1940 1960 1980 2000 202025th percen Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 154 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 High Pulse Count Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 30 <>------<------>

75th percen 15 Number

10 median

25th percen

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 155 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American RiverHigh PulseNear Duration Placerville (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 40 <>------<------>

20 Days

75th percen

median

25th percen 0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 156 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA

B-4445 South Fork American River RiseNear Rate Placerville (Natural), April 2004 Pre-Impact Period Post-Impact Period 1875 1901 1975 2001 1000 <>------<------>

900

800

700

600

500 75th percen CFS/Day 400

300 median

200 25th percen

100

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 157 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South Fork American River Near Placerville (Natural), April 2004 Fall Rate

0 1875Pre-Impact<>------Period 1901 Post-Impact < 1975------Period 2001 >

-100

-200 75th percen

median -300

25th percen CFS/Day -400

-500

-600

-700 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 158 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

Standard IHA B-4445 South ForkPre-Impact American Period River Near Placerville (Natural), Post-Impact Period April 2004 Reversals 1875 1901 1975 2001

240 <>------<------>

220 75th percen

200

median 180 25th percen

Number 160

140

120

100 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.ann, P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.baw

04/21/04 Page 159 of 160 (4) Gage B - South Fork American River at Chili Bar Reservoir (Natural) versus 4445 South Fork American River Near Placerville (Regulated)

B-4445 South Fork American River Near Placerville (Natural), April 2004

80000

70000

60000

50000

40000

30000 Cubic Feet per Second 20000

10000

0 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year

File(s) Used: P:\Framatome-IHA\IHA Apr04\4-GageB-Nat\GB-N.dat

04/21/04 Page 160 of 160

Appendix F

Diurnal Daily Fluctuation

• Diurnal Fluctuation Study

(Provided in Hardcopy and on CD)

Diurnal Fluctuation Study

The following plots are included in this attachment:

Small Drainage Areas Figure 1-1 Tahoe Creek at Hwy 89 near Tahoe Figure 1-2 Tahoe Creek at Hwy 89 near Tahoe (Averaged four-day) Figure 1-3 Ward Creek at Hwy 89 near Tahoe Pines Figure 1-4 Ward Creek at Hwy 89 near Tahoe Pines (Averaged four-day) Figure 1-5 Blackwood Creek near Tahoe City Figure 1-6 Blackwood Creek near Tahoe City (Averaged four-day)

Large Drainage Areas Figure 1-7 Merced River at Happy Isle Figure 1-8 Merced River at Happy Isle (Averaged four-day) Figure 1-9 Merced River at Pohono Bridge Figure 1-10 Merced River at Pohono Bridge (Averaged four-day) Figure 1-11 North Fork American River at North Fork Dam (minor regulation) Figure 1-11 North Fork American River at North Fork Dam (minor regulation, averaged four- day)

2.6 Trout Creek near Tahoe Valley 2.5 1990 1991 2.4 1992 1993 1994 2.3 1995 1996 2.2 1997 1998 2.1 1999 2000 2 2001

1.9

1.8

1.7

1.6

1.5 Maximum Flow as a Percentage of the Mean Daily Daily Flow Mean the of a Percentage as Flow Maximum 1.4

1.3

1.2

1.1

100 80 60 40 20 0 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-1

2.6 Trout Creek near Tahoe Valley 2.5 1990 1991 2.4 1992 1993 1994 2.3 1995 1996 2.2 1997 1998 2.1 1999 2000 2 2001

1.9

1.8

1.7

1.6

1.5

1.4

Averaged Four-day Maximum Flow as a Percentage of the Mean Daily Daily Flow Mean the of a Percentage as Flow Maximum Four-day Averaged 1.3

1.2

1.1

100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-2

2.6 Ward Creek at Hwy 89 near Tahoe Pines 2.5 1990 1991

2.4 1992 1993 1994 2.3 1995 1996 2.2 1997 1998 2.1 1999 2000 2 2001

1.9

1.8

1.7

1.6

1.5 Maximum Flow as a Percentage of the Mean Daily Flow Mean the of a Percentage as Flow Maximum

1.4

1.3

1.2

1.1

1 100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-3

2.6 Ward Creek at Hwy 89 near Tahoe Pines 2.5 1990 1991 2.4 1992 1993 2.3 1994 1995

2.2 1996 1997 1998 2.1 1999 2000 2 2001

1.9

1.8

1.7

1.6

1.5

1.4

Averaged Four-day Maximum Flow as a Percentage of the Mean Daily Flow Mean the of a Percentage as Flow Maximum Four-day Averaged 1.3

1.2

1.1

100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-4

2.6 Blackwood Creek near Tahoe City 2.5 1990 1991 1992 2.4 1993 1994 2.3 1995 1996 2.2 1997 1998 2.1 1999 2000 2001 2

1.9

1.8

1.7

1.6

1.5 Maximum Flow as a Percentage of the Mean Daily Daily Flow Mean the of aPercentage as Flow Maximum 1.4

1.3

1.2

1.1

100 80 60 40 20 0 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-5

2.6 Blackwood Creek near Tahoe City 2.5 1990 1991 1992 2.4 1993 1994 2.3 1995 1996 2.2 1997 1998 2.1 1999 2000

2 2001

1.9

1.8

1.7

1.6

1.5

1.4

Averaged Four-day Maximum Flow as a Percentage of the Mean Daily Flow Mean the of a Percentage as Flow Maximum Four-day Averaged 1.3

1.2

1.1

100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-6

2.6 Merced River at Happy Isle 2.5 1990 1991 2.4 1992 1993

2.3 1994 1995

2.2 1996 1997 1998 2.1 1999 2000 2 2001 2002 1.9

1.8

1.7

1.6

1.5 Maximum Flow as a Percentage of the Mean Daily Mean Flow the of a Percentage as Flow Maximum 1.4

1.3

1.2

1.1

100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-7

2.6 Merced River at Happy Isle 1990 2.5 1991 1992 2.4 1993 1994 2.3 1995 1996 2.2 1997 1998 2.1 1999 2000 2 2001 2002 1.9

1.8

1.7

1.6

1.5

1.4

Averaged Four-day Maximum Flow as a Percentage of the Mean Daily Daily Flow Mean the of a Percentage as Flow Maximum Four-day Averaged 1.3

1.2

1.1

100 80 60 40 20 0 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-8

2.6 Merced River at Pohono Bridge 2.5 1990 1991 2.4 1992 1993 1994 2.3 1995 1996 2.2 1997 1998 2.1 1999 2000 2 2001

1.9

1.8

1.7

1.6

1.5 Maximum Flow as a Percentage of the Mean Daily Daily Flow Mean the of a Percentage as Flow Maximum 1.4

1.3

1.2

1.1

100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-9

2.6 Merced River at Pohono Bridge 2.5 1990 1991 2.4 1992 1993 1994 2.3 1995 1996 2.2 1997 1998 2.1 1999 2000 2 2001

1.9

1.8

1.7

1.6

1.5

1.4

Averaged Four-day Maximum Flow as a Percentage of the Mean Daily Daily Flow Mean the of a Percentage as Flow Maximum Four-day Averaged 1.3

1.2

1.1

100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-10

2.6 North Fork American River at the North Fork Dam 2.5 Regulated Flow 1990 1991 2.4 1992 1993 2.3 1994 1995 2.2 1996 1997 2.1 1998 1999 2 2000 2001

1.9 2002

1.8

1.7

1.6

1.5 Maximum Flow as a Percentage of the Mean Daily Daily Flow Mean the of a Percentage as Flow Maximum 1.4

1.3

1.2

1.1

100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-11

2.6 North Fork American River at the North Fork Dam 2.5 Regulated Flow 1990 1991 2.4 1992 1993 2.3 1994 1995 2.2 1996 1997 2.1 1998 1999 2 2000 2001

1.9 2002

1.8

1.7

1.6

1.5

1.4

Averaged Four-day Maximum Flow as a Percentage of the Mean Daily Daily Flow Mean the of a Percentage as Flow Maximum Four-day Averaged 1.3

1.2

1.1

100806040200 Remaining April-July Flow, as a Percentage of the total April-July Flow (%)

Figure 1-12

Appendix G

Flood Peak Frequency Data and Curves

• UARP Project Instantaneous Flow

(Provided in Hardcopy and on CD)

UARP Project Instantaneous Flow

The following plots have been prepared from the USGS gage data:

• Rubicon River at Rubicon Springs near Meeks Bay (Table 1 and Figure 1-1) o Unregulated by UARP: 1956-1963 o Regulated by UARP: 1964-1986

• Gerle Creek below Loon Lake Dam (Table 2 and Figure 1-2) o Unregulated by UARP: not available o Regulated by UARP: 1964-2001

• South Fork Rubicon River below Gerle Creek near Georgetown (Table 3 and Figure 1-3) o Unregulated by UARP: not available o Regulated by UARP 1964-2001

• South Fork Silver Creek near Ice House (Figure 1-4) o Unregulated by UARP: 1925-1959 o Regulated by UARP: without Jones Fork Powerhouse: 1961-1984 o Regulated by UARP: with Jones Fork Powerhouse: 1985-2001

• South Fork Silver Creek near Ice House (Table 4 and Figure 1-5) o Unregulated by UARP: 1925-1959 o Regulated by UARP: without Jones Fork Powerhouse: 1961-1984 o Regulated by UARP: with Jones Fork Powerhouse: 1985-2001 (excl 1996) Note: During 1996, the gates at the Ice House Reservoir were opened which created a spill downstream. Because this was an abnormal event, it was removed from the analysis.

• Silver Creek near Union Valley (Table 5 and Figure 1-6) o Unregulated by UARP: 1925-1960 o Regulated by UARP: not available

• Silver Creek below Camino Diversion Dam (Table 6 and Figure 1-7) o Unregulated: Silver Creek near Placerville (DA 177 sqmi, 1922-59) o Regulated: Silver Creek below Camino Diversion Dam (DA 171 sqmi, 1964- 2001)

• South Fork American River near Camino (Table 7 and Figure 1-8) o Unregulated: 1923-1961 o Regulated: 1963-2001

Table 1 114428000 Rubicon R @ Rubicon Springs Instantaneous Peak Flow (cfs) DA 31.4 sqmi Prior to SMUD UARP Subsequent SMUD UARP Date Flow Flow/sqmi Date Flow Flow/sqmi 2/9/1961 850 27.1 2/21/1977 119 3.8 1/9/1959 887 28.2 11/18/1965 141 4.5 5/8/1962 960 30.6 4/14/1985 152 4.8 5/23/1958 1660 52.9 4/5/1972 160 5.1 2/8/1960 2460 78.3 2/14/1981 219 7.0 5/18/1957 3030 96.5 12/15/1977 338 10.8 12/1955 9270 295.2 6/6/1975 452 14.4 2/1/1963 11500 366.2 12/17/1972 606 19.3 2/20/1968 630 20.1 6/14/1969 630 20.1 6/17/1967 805 25.6 10/26/1975 2570 81.8 11/11/1983 2650 84.4 1/11/1979 2660 84.7 3/8/1986 3170 101.0 11/14/1963 3350 106.7 1/21/1970 3470 110.5 11/12/1973 3750 119.4 6/26/1971 3850 122.6 10/26/1982 3870 123.2 2/16/1982 4750 151.3 1/13/1980 5270 167.8 12/23/1964 10100 321.7 Note: Values in red represent the event with a 2-year return period. Values in blue are assumed to be either snowmelt or rain on snow events (April through June).

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 11428000 Rubicon River at Rubicon Springs near Meeks Bay 80000 70000 Instantaneous 60000 DA 31.4 sqmi Elev 6053' 50000 WY1956 to WY1963 40000 WY1964 to WY1986

30000

20000

10000 9000 8000 7000 6000 5000

4000

3000 Flow in cfs 2000

1000 900 800 700 600 500

400

300

200

100 5 2 1 60 30 10 95 80 50 40 20 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 1-1

Table 2 11429500 Gerle Ck blw Loon Lake Dam Instantaneous Peak Flow (cfs) DA 8.01 sqmi Subsequent to SMUD UARP Date Flow Flow/sqmi 10/26/1975 11 1.4 5/14/1978 12 1.5 5/18/1975 13 1.6 11/11/1971 17 2.1 6/8/1977 17 2.1 1/11/1979 17 2.1 10/22/1980 18 2.2 10/23/1989 19 2.4 7/15/1973 20 2.5 12/6/1987 21 2.6 2/14/2000 23 2.9 10/25/1982 25 3.1 6/8/1994 25 3.1 3/4/1991 28 3.5 6/14/1974 29 3.6 11/23/1988 31 3.9 10/24/1979 32 4.0 6/24/1999 33 4.1 7/11/1995 67 8.4 8/18/1998 67 8.4 11/18/1996 74 9.2 8/4/2001 94 11.7 4/22/1992 123 15.4 8/21/1985 132 16.5 8/11/1993 197 24.6 5/28/1982 212 26.5 7/29/1986 306 38.2 7/31/1964 327 40.8 8/26/1987 337 42.1 12/27/1983 370 46.2 9/18/1966 422 52.7 12/13/1967 470 58.7 6/8/1970 477 59.6 5/18/1996 510 63.7 7/5/1967 839 104.7 6/14/1965 863 107.7 6/27/1971 980 122.3 6/5/1969 1050 131.1 Note: Values in red represent the event with a 2-year return period. Values in blue are assumed to be either snowmelt or rain on snow events (April through June).

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 11429500 Gerle Ck blw Loon Lake Dam 8000 7000 Instantaneous 6000 DA 8.01 sqmi Elev 6250' 5000 WY1925 to WY1960 4000

3000

2000

1000 900 800 700 600 500

400

300 Flow in cfs 200

100 90 80 70 60 50

10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 1-2

Table 3 11430000 South Fork Rubicon R blw Gerle Creek nr Georgetown Instantaneous Peak Flow (cfs) DA 47.6 sqmi Subsequent to SMUD UARP Date Flow Flow/sqmi 10/15/1993 14 0.3 2/20/1992 29 0.6 12/26/1975 30 0.6 9/13/1977 33 0.7 6/22/2001 50 1.1 11/12/1971 86 1.8 11/5/1963 129 2.7 2/16/1990 159 3.3 12/20/1965 185 3.9 3/11/1981 195 4.1 2/9/1999 239 5.0 2/12/1988 247 5.2 5/19/1975 284 6.0 4/25/1978 294 6.2 2/20/1968 362 7.6 3/8/1989 510 10.7 2/9/1985 720 15.1 2/13/1987 734 15.4 4/17/1993 864 18.2 2/14/2000 1190 25.0 1/11/1979 1200 25.2 3/26/1971 1310 27.5 1/12/1973 1390 29.2 3/24/1998 1980 41.6 11/12/1973 2070 43.5 3/16/1967 2210 46.4 1/20/1969 2760 58.0 3/13/1983 2760 58.0 3/4/1991 2790 58.6 5/1/1995 3340 70.2 11/24/1983 4000 84.0 1/21/1970 5350 112.4 5/16/1996 5670 119.1 2/16/1982 6160 129.4 2/17/1986 7720 162.2 1/13/1980 8580 180.3 12/23/1964 8620 181.1 1/1/1997 12600 264.7 Note: Values in red represent the event with a 2-year return period. Values in blue are assumed to be either snowmelt or rain on snow events (April through June).

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 11430000 South Fork Rubicon River Below Gerle Creek nr Georgetown 70000 Instantaneous 60000 DA 47.6 sqmi Elev 4970' 50000 40000 WY1964 to WY2001 30000

20000

10000 9000 8000 7000 6000 5000 4000

3000

2000

1000 900 800 700 Flow in cfs 600 500 400

300

200

100 90 80 70 60 50 40

10 5 2 1 60 30 10 95 80 50 40 20 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 1-3

Table 4 11441500 South Fork Silver Creek nr Ice House Instantaneous Peak Flow (cfs) DA 27.5 sqmi Prior to SMUD UARP Subsequent SMUD UARP Subsequent JFPH Flow/ Flow/ Flow/ Date Flow sqmi Date Flow sqmi Date Flow sqmi 4/28/1931 217 8 10/26/1976 296 11 10/1/1993 16 1 4/20/1939 339 12 10/28/1977 394 14 3/4/1991 19 1 5/20/1930 409 15 6/6/1984 411 15 4/27/1988 21 1 4/28/1926 450 16 9/26/1972 418 15 11/3/1999 25 1 5/7/1944 526 19 10/20/1975 439 16 6/23/1999 82 3 3/29/1934 558 20 10/14/1974 476 17 8/17/1989 114 4 5/9/1959 587 21 3/26/1973 494 18 8/11/1993 159 6 5/2/1947 602 22 8/17/1979 513 19 4/3/1990 214 8 5/21/1955 635 23 10/14/1980 519 19 4/22/1992 252 9 5/5/1946 636 23 11/6/1965 536 19 8/14/2001 296 11 5/16/1932 648 24 3/11/1969 545 20 8/26/1987 334 12 5/26/1948 689 25 6/1/1963 560 20 6/26/1995 460 17 5/30/1933 692 25 5/23/1961 568 21 6/20/1998 466 17 3/9/1954 746 27 1/28/1980 570 21 11/19/1984 514 19 5/11/1941 750 27 10/22/1967 592 22 3/8/1986 1000 36 6/4/1945 750 27 6/3/1964 602 22 1/2/1997 4440 161 5/23/1935 760 28 8/25/1965 627 23 5/29/1950 764 28 6/30/1967 672 24 6/15/1929 775 28 7/9/1974 749 27 5/14/1937 782 28 6/24/1983 783 28 2/6/1925 785 29 6/11/1962 802 29 5/14/1949 792 29 6/27/1971 890 32 5/16/1927 800 29 1/22/1970 1800 65 5/23/1958 823 30 5/26/1982 1930 70 6/7/1936 828 30 5/27/1952 865 31 3/26/1940 942 34 12/3/1941 959 35 5/18/1957 1070 39 1/10/1953 1090 40 6/1/1943 1110 40 3/25/1928 1950 71 12/11/1937 2640 96 11/18/1950 3900 142 12/23/1955 3940 143 Note: Values in red represent the event with a 2-year return period. Values in blue are assumed to be either snowmelt or rain on snow events (April through June).

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 11441500 South Fork Silver Creek nr Ice House 8000 7000 Instantaneous Flow 6000 DA 27.5 sqmi Elev 5290' 5000 WY1925 to WY1959 4000 WY1961 to WY1984 WY1985 to WY2001 3000

2000

1000 900 800 700 600 500

400

300 Flow in cfs 200

100 90 80 70 60 50

10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 1-4

Recurrence Interval in Years

2000

1000 900 800 700 600 500

400

300 Flow in cfs 200

100 90 80 70 60 50

10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 1-5

Table 5 11441000 Silver Ck @ Union Valley Instantaneous Peak Flow (cfs) DA 82.7 sqmi Subsequent to SMUD UARP Date Flow Flow/sqmi 3/18/1931 680 8.2 1/10/1959 796 9.6 4/21/1930 950 11.5 4/7/1939 960 11.6 4/5/1926 1420 17.2 5/2/1947 1450 17.5 5/21/1955 1610 19.5 5/7/1944 1690 20.4 5/5/1946 1840 22.2 5/29/1933 1970 23.8 5/16/1932 2040 24.7 5/11/1941 2120 25.6 5/26/1948 2160 26.1 5/21/1935 2250 27.2 3/29/1934 2330 28.2 5/14/1949 2330 28.2 5/16/1927 2350 28.4 5/13/1937 2390 28.9 5/27/1952 2830 34.2 2/8/1960 2830 34.2 5/23/1958 2890 34.9 6/15/1929 3360 40.6 6/7/1936 3390 41.0 4/27/1953 3510 42.4 3/9/1954 3540 42.8 12/3/1941 3860 46.7 2/2/1945 4190 50.7 5/18/1957 4430 53.6 2/6/1925 5770 69.8 3/26/1940 5800 70.1 1/21/1943 7010 84.8 3/25/1928 9430 114.0 12/11/1937 10200 123.3 11/20/1950 12100 146.3 12/23/1955 15800 191.1 Note: Values in red represent the event with a 2-year return period. Values in blue are assumed to be either snowmelt or rain on snow events (April through June).

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 11441000 Silver Ck @ Union Valley 80000 70000 Instantaneous 60000 DA 82.7 sqmi Elev 4530' 50000 WY1925 to WY1960 40000

30000

20000

10000 9000 8000 7000 6000 5000

4000

3000 Flow in cfs 2000

1000 900 800 700 600 500

400

300

200

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 1-6

Table 6 Silver Creek near Placerville (DA 177 sqmi, 1922-59) Silver Creek below Camino Diversion Dam (DA 171 sqmi, 1964-2001) Instantaneous Peak Flow (cfs) Prior to SMUD UARP Subsequent SMUD UARP 11442000 Silver Ck near Placerville 11441900 Silver Ck blw Camino Diversion Dam DA 177 sqmi DA 171 sqmi Date Flow Flow/sqmi Date Flow Flow/sqmi 2/8/1924 915 5.2 1/11/1988 28 0.2 3/18/1931 1070 6.0 10/15/1993 28 0.2 1/10/1959 1300 7.3 2/29/1976 30 0.2 4/8/1939 1470 8.3 11/27/1984 53 0.3 4/22/1930 1560 8.8 2/20/1992 62 0.4 5/3/1947 2110 11.9 2/13/1987 67 0.4 5/22/1955 2150 12.1 10/9/2000 70 0.4 4/5/1926 2250 12.7 1/17/1978 115 0.7 5/8/1944 2320 13.1 3/25/1981 127 0.7 5/12/1932 2780 15.7 11/10/1976 159 0.9 3/29/1934 2910 16.4 3/24/1975 162 0.9 4/6/1923 3020 17.1 12/4/1967 170 1.0 5/30/1933 3040 17.2 10/1/1963 259 1.5 5/26/1948 3110 17.6 12/22/1971 550 3.2 5/11/1941 3180 18.0 2/21/1991 586 3.4 12/29/1945 3180 18.0 1/11/1979 677 4.0 5/14/1949 3420 19.3 2/14/2000 688 4.0 1/22/1950 3680 20.8 1/12/1973 978 5.7 5/14/1937 3840 21.7 2/17/1990 1500 8.8 5/30/1922 3860 21.8 11/2/1965 1650 9.6 5/27/1952 4060 22.9 3/26/1971 1770 10.4 2/21/1927 4260 24.1 5/11/1967 2800 16.4 3/9/1954 4410 24.9 6/16/1998 3080 18.0 5/23/1958 4540 25.6 2/9/1999 3460 20.2 6/16/1929 4660 26.3 1/21/1969 4020 23.5 4/27/1953 4820 27.2 3/8/1989 6150 36.0 1/27/1942 5790 32.7 3/13/1983 6660 38.9 5/18/1957 6030 34.1 1/22/1970 7540 44.1 4/8/1935 6240 35.3 12/30/1973 8280 48.4 2/22/1936 6800 38.4 5/1/1995 10700 62.6 2/6/1925 7330 41.4 5/16/1996 13000 76.0 2/2/1945 10400 58.8 2/15/1982 13100 76.6 3/26/1940 10800 61.0 12/22/1964 13600 79.5 1/21/1943 15800 89.3 11/17/1983 13800 80.7 3/25/1928 17600 99.4 1/13/1980 14000 81.9 12/11/1937 23000 129.9 1/22/1993 14300 83.6 11/18/1950 25800 145.8 2/17/1986 22800 133.3 12/23/1955 27500 155.4 1/2/1997 47700 278.9 Note: Values in red represent the event with a 2-year return period. Values in blue are assumed to be either snowmelt or rain on snow events (April through June).

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 70000 Instantaneous Flow 60000 50000 11442000 Silver Creek near Placerville 40000 WY 1922 to WY 1959 30000 DA 177 sqmi Elev 2070' Silver C bl Camino Diversion Dam 20000 WY1964 to 2001 DA 171 sqmi 2754' Elev

10000 9000 8000 7000 6000 5000 4000

3000

2000

1000 900 800 700 Flow in cfs 600 500 400

300

200

100 90 80 70 60 50 40

10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 1-7

11443500 South Fork American River nr Camino Instantaneous Peak Flow (cfs) DA 493 sqmi Prior to SMUD UARP Subsequent SMUD UARP Date Flow Flow/sqmi Date Flow Flow/sqmi 4/29/1931 1620 3.3 9/13/1977 30 0.1 2/8/1924 1970 4.0 10/3/2000 41 0.1 5/23/1961 2320 4.7 8/16/1976 43 0.1 4/8/1939 2650 5.4 6/29/1994 48 0.1 2/16/1959 2850 5.8 6/16/1992 50 0.1 3/29/1934 4010 8.1 4/24/1972 67 0.1 4/8/1930 4100 8.3 6/3/1987 72 0.1 5/9/1944 4450 9.0 6/20/1988 78 0.2 5/3/1947 4500 9.1 6/15/1978 84 0.2 4/5/1926 4510 9.1 11/5/1984 97 0.2 5/22/1955 4950 10.0 10/27/1980 184 0.4 5/30/1933 5930 12.0 7/12/1973 479 1.0 5/29/1950 6080 12.3 2/21/1990 639 1.3 5/12/1932 6200 12.6 1/11/1979 848 1.7 5/14/1949 6460 13.1 3/8/1989 935 1.9 5/27/1948 6580 13.3 3/4/1991 1400 2.8 5/12/1941 6990 14.2 2/21/1968 1700 3.4 12/22/1945 7110 14.4 2/14/2000 1870 3.8 5/14/1937 7140 14.5 3/25/1975 1900 3.9 4/6/1923 7350 14.9 12/30/1973 2480 5.0 6/16/1929 8300 16.8 5/13/1966 2820 5.7 5/23/1958 8350 16.9 1/22/1993 4400 8.9 3/9/1954 9340 18.9 11/15/1963 4450 9.0 2/21/1927 9350 19.0 3/26/1971 5100 10.3 5/28/1952 9420 19.1 3/24/1998 6420 13.0 2/8/1960 10200 20.7 2/9/1999 7780 15.8 5/18/1957 10400 21.1 3/16/1967 8260 16.8 4/27/1953 10600 21.5 1/21/1969 12500 25.4 4/8/1935 10700 21.7 12/26/1983 13500 27.4 2/22/1936 11700 23.7 5/1/1995 14300 29.0 1/27/1942 13300 27.0 3/13/1983 15000 30.4 2/6/1925 18000 36.5 5/16/1996 19500 39.6 3/27/1940 18400 37.3 1/21/1970 24500 49.7 2/2/1945 19100 38.7 2/16/1982 27500 55.8 1/21/1943 23100 46.9 2/18/1986 27500 55.8 3/25/1928 31500 63.9 1/13/1980 30900 62.7 12/11/1937 34400 69.8 12/23/1964 36000 73.0 11/21/1950 46000 93.3 2/1/1963 37200 75.5 12/23/1955 49800 101.0 1/2/1997 62300 126.4 Note: Values in red represent the event with a 2-year return period. Values in blue are assumed to be either snowmelt or rain on snow events (April through June).

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 11443500 South Fork American River nr Camino 70000 Instantaneous Flow 60000 DA 493 sqmi Elev 1625' 50000 40000 WY1923 to WY1961 30000 WY1963 to WY2001

20000

10000 9000 8000 7000 6000 5000 4000

3000

2000

1000 900 800 700 Flow in cfs 600 500 400

300

200

100 90 80 70 60 50 40

10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 1-8

South Fork American River near Placerville Instantaneous Flow

Regulated data: A gage on the South Fork American River (SFAR) exists near Placerville, recording flows of a drainage area of 598 square miles. This data that represents a regulated stream flow (regulation due to UARP and Project 184) exists for the period 1965-2001. These data are graphically displayed on Figure 2-1.

Unregulated Data: Fow data from the following gages was available prior to regulation by the UARP: • SFAR @ Placerville, 598 square miles, 1912-1920 • SFAR @ Coloma, 631 square miles, 1930-1941 • SFAR @ Lotus, 673 square miles, 1951-1962

The results shown in the figures described below have been developed with use of the data described above:

Figure 2-2 SFAR @ Coloma and SFAR @ Lotus have been adjusted by the percentage of the difference in areas (80%) to adjust for differences in annual precipitation (which was not available). For example, the difference in area between SFAR @ Placerville and SFAR @ Coloma is 33 sqmi (631-598). Taking 80% of the difference is 26.4 (33 *.8). The adjustment factor for SFAR @ Coloma is .958 (598/[598+26.4]). • SFAR @ Placerville, 598 square miles, 1912-1920 • SFAR @ Coloma, 631 square miles, 1930-1941 * (.958) • SFAR @ Lotus, 673 square miles, 1951-1962 * (.9108)

Figure 2-3 SFAR @ Coloma and SFAR @ Lotus have been adjusted by the percentage of the difference in areas. The adjustment factor for SFAR @ Coloma is .948 (598/631). • SFAR @ Placerville, 598 square miles, 1912-1920 • SFAR @ Coloma, 631 square miles, 1930-1941 * (.948) • SFAR @ Lotus, 673 square miles, 1951-1962 * (.889)

Figure 2-4 No adjustment made to SFAR @ Coloma or SFAR @ Lotus. • SFAR @ Placerville, 598 square miles, 1912-1920 • SFAR @ Coloma, 631 square miles, 1930-1941 • SFAR @ Lotus, 673 square miles, 1951-1962

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 11444500 South Fork American River nr Placerville 80000 Instantaneous Flow DA 598 sqmi Elev 931' 70000

60000 WY1965 to WY2001

50000

40000

30000

20000

10000 9000

Flow in cfs 8000

7000

6000

5000

4000

3000

2000

1000 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 2-1

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 Available Data (80% area adjustment to flow) SFAR @ Placerville, 598 sqmi, 1912-1920 & 1964-present 80000 SFAR @ Coloma, 631 sqmi, 1930-41 (.958) SFAR @ Lotus, 673 sqmi, WY1951-95 & WY97 (.9108) 70000 Attempt to use a combination of 3 gages for pre-SMUD record. Assumption that earlier record would not be impacted by regulation as 60000 much as post SMUD data.

50000

40000

30000

20000

10000 9000

Flow in cfs 8000

7000

6000

5000

4000

3000

2000 Instantaneous Flow 11444500 South Fork American River nr Placerville WY1965 to WY2001 DA 598 sqmi Elev 931' Estimated South Fork American River nr Placerville 1912-20, 1930-41, 1951-62

1000 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 2-2

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 Available Data (Adjustment by area) SFAR @ Placerville, 598 sqmi, 1912-1920 & 1964-present 80000 SFAR @ Coloma, 631 sqmi, 1930-41 (.948) SFAR @ Lotus, 673 sqmi, WY1951-95 & WY97 (.889) 70000 Attempt to use a combination of 3 gages for pre-SMUD record. Assumption that earlier record would not be impacted by regulation as 60000 much as post SMUD data.

50000

40000

30000

20000

10000 9000

Flow in cfs 8000

7000

6000

5000

4000

3000

2000 Instantaneous Flow 11444500 South Fork American River nr Placerville WY1965 to WY2001 DA 598 sqmi Elev 931' Estimated South Fork American River nr Placerville 1912-20, 1930-41, 1951-62

1000 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 2-3

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 Available Data (No Flow Adjustment) SFAR @ Placerville, 598 sqmi, 1912-1920 & 1964-present 80000 SFAR @ Coloma, 631 sqmi, 1930-41 SFAR @ Lotus, 673 sqmi, WY1951-95 & WY97 70000 Attempt to use a combination of 3 gages for pre-SMUD record. Assumption that earlier record would not be impacted by regulation as 60000 much as post SMUD data.

50000

40000

30000

20000

10000 9000

Flow in cfs 8000

7000

6000

5000

4000

3000

2000 Instantaneous Flow 11444500 South Fork American River nr Placerville WY1965 to WY2001 DA 598 sqmi Elev 931' Estimated South Fork American River nr Placerville 1912-20, 1930-41, 1951-62

1000 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 2-4

UARP Project Mean Daily Flow

Many of the previous figures span varying hydrological periods. In an attempt to illustrate the potential differences between the use of differing hydrological periods, flood peak frequency curves were prepared for a site where a long-term flow record exists. The unimpaired flow for South Fork Silver Creek near Ice House Reservoir was evaluated. The following plots have been prepared:

• South Fork Silver Creek near Ice House (Figure 3-1) o 1925-2001 o 1956-1986 o 1956-1963 o 1964-1986 o Compare with Rubicon River at Rubicon Springs near Meeks Bay (Figure 1-1)

• South Fork Silver Creek near Ice House (Figure 3-2) o 1956-1963 o 1964-1986 o Compare with Rubicon River at Rubicon Springs near Meeks Bay (Figure 1-1)

• South Fork Silver Creek near Ice House (Figure 3-3) o 1925-2001 o 1925-1961 o 1963-2001 o Compare with South Fork American River near Camino (Figure 1-8)

• South Fork Silver Creek near Ice House (Figure 3-4) o 1925-2001 o 1925-1959 o 1964-2001 o Compare with • Gerle Creek below Loon Lake Dam (Figure 1-2) • South Fork Rubicon River below Gerle Creek near Georgetown (Figure 1- 3) • Silver Creek at Union Valley (Figure 1-6)

• South Fork Silver Creek near Ice House (Figure 3-5) o 1925-2001 (excl 60) o 1925-1959 o 1961-1984 o 1985-2001 o Compare with South Fork Silver Creek near Ice House (figures 1-4 and 1-5)

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 Computed Unimpaired Mean Daily Flow 8000 South Fork Silver Creek nr Ice House DA 27.5 sqmi Elev 5290' 7000

6000 WY1925 to WY2001 WY1956 to WY1986 5000 WY1956 to WY1963 WY1964 to WY1986 4000

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 95 80 50 40 20 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 3-1

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 Computed Unimpaired Mean Daily Flow 8000 South Fork Silver Creek nr Ice House DA 27.5 sqmi Elev 5290' 7000

6000 WY1956 to WY1963 WY1964 to WY1986 5000

4000

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 3-2

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 Computed Unimpaired Mean Daily Flow 8000 South Fork Silver Creek nr Ice House DA 27.5 sqmi Elev 5290' 7000

6000 WY1925 to WY2001 WY1925 to WY1961 5000 WY1963 to WY2001

4000

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 3-3

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 Computed Unimpaired Mean Daily Flow 8000 South Fork Silver Creek nr Ice House DA 27.5 sqmi Elev 5290' 7000

6000 WY1925 to WY2001 WY1925 to WY1959 5000 WY1964 to WY2001

4000

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 3-4

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 Computed Unimpaired Mean Daily Flow 8000 South Fork Silver Creek nr Ice House DA 27.5 sqmi Elev 5290' 7000

6000 WY1925 to WY2001 (exc 60) WY1925 to WY1959 5000 WY1961 to WY1984 WY1985 to WY2001 4000

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 95 80 50 40 20 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 3-5

Outside UARP Project Instantaneous Flow

Additional analyses were performed to allow hydrologic comparisons to be made with basins located outside of the American River Basin. The following plots have been prepared:

• Middle Fork Tuolumne River at Oakland Recreation Camp. USGS rates these records as good. There are small upstream diversions. o Figure 4-1 • 1922-2001, 1922-1959, 1961-1984, 1985-2001 • Compare with South Fork Silver Creek near Ice House (figures 1-4 and 1- 5) o Figure 4-2 • 1922-2001, 1922-1959, 1964-2001 • Compare with • Gerle Creek below Loon Lake Dam (Figure 1-2) • South Fork Rubicon River below Gerle Creek near Georgetown (Figure 1-3) • South Fork Silver Creek near Ice House (figures 1-4 and 1-5) • Silver Creek at Union Valley (Figure 1-6) o Figure 4-3 • 1922-2001, 1923-1961, 1963-2001 • Compare with South Fork American River near Camino (Figure 1-8)

• Middle Fork Mokelumne River at West Point. USGS rates these records as good. Flow regulated by Middle Fork Reservoir, capacity 1,740 acre-feet and several small diversions upstream. o Figure 4-4 • 1912-20, 1930-1941, 1951-1962, 1965-2001 • Compare with SFAR @ Placerville (figures 2-1 and 2-4) o Figure 4-5 • 1912-2001, 1912-20, 1930-1941, 1951-1962, 1965-2001 • Compare with SFAR @ Placerville (figures 2-1 and 2-4) o Figure 4-6 • 1922-2001, 1922-1959, 1961-1984, 1985-2001 • Compare with South Fork Silver Creek near Ice House (figures 1-4 and 1- 5)

o Figure 4-7 • 1912-2001, 1922-1959, 1964-2001 • Compare with • Gerle Creek below Loon Lake Dam (Figure 1-2) • South Fork Rubicon River below Gerle Creek near Georgetown (Figure 1-3) • South Fork Silver Creek near Ice House (figures 1-4 and 1-5) • Silver Creek at Union Valley (Figure 1-6) o Figure 4-8 • 1912-2001, 1923-1961, 1963-2001 • Compare with South Fork American River near Camino (Figure 1-8)

• Merced River at Happy Isle Bridge. USGS rates these records as good. Small diversions upstream. o Figure 4-9 • 1912-20, 1930-1941, 1951-1962, 1965-2001 • Compare with SFAR @ Placerville (figures 2-1 and 2-4) o Figure 4-10 • 1912-2001, 1912-20, 1930-1941, 1951-1962, 1965-2001 • Compare with SFAR @ Placerville (figures 2-1 and 2-4) o Figure 4-11 • 1922-2001, 1922-1959, 1961-1984, 1985-2001 • Compare with South Fork Silver Creek near Ice House (figures 1-4 and 1- 5) o Figure 4-12 • 1912-2001, 1922-1959, 1964-2001 • Compare with • Gerle Creek below Loon Lake Dam (Figure 1-2) • South Fork Rubicon River below Gerle Creek near Georgetown (Figure 1-3) • South Fork Silver Creek near Ice House (figures 1-4 and 1-5) • Silver Creek at Union Valley (Figure 1-6) o Figure 4-13 • 1912-2001, 1923-1961, 1963-2001 • Compare with South Fork American River near Camino (Figure 1-8)

• Cole Creek near Salt Springs Dam. Occasional pumping for summer use. o Figure 4-14 • 1928-2001 (excl 76), 1928-1959, 1961-1984 (excl 76), 1985-2001 • Compare with South Fork Silver Creek near Ice House (figures 1-4 and 1- 5)

o Figure 4-15 • 1928-2001 (excl 76), 1956-1963, 1964-1986 (excl 76) • Compare with Rubicon River at Rubicon Springs near Meeks Bay (Figure 1-1)

• North Fork Yuba River below Goodyears Bar. USGS rates these records as good. Small diversions upstream. o Figure 4-16 • 1931-2001, 1931-1959, 1961-1984, 1985-2001 • Compare with South Fork Silver Creek near Ice House (figures 1-4 and 1- 5)

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 11282000 Middle Fork Tuolumne River at 8000 Oakland Recreation Camp Instantaneous Flow 7000 DA 73.5 sqmi Elev 2800' 6000 Records good. Small diversions upstream.

5000 WY1922 to WY2001 WY1922 to WY1959 4000 WY1961 to WY1984 WY1985 to WY2001 3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-1

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 11282000 Middle Fork Tuolumne River at 8000 Oakland Recreation Camp Instantaneous Flow 7000 DA 73.5 sqmi Elev 2800' 6000 Records good. Small diversions upstream.

5000 WY1922 to WY2001 WY1922 to WY1959 4000 WY1964 to WY2001

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 95 80 50 40 20 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-2

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 11282000 Middle Fork Tuolumne River at 8000 Oakland Recreation Camp Instantaneous Flow 7000 DA 73.5 sqmi Elev 2800' 6000 Records good. Small diversions upstream.

5000 WY1922 to WY2001 WY1923 to WY1961 4000 WY1963 to WY2001

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 95 80 50 40 20 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-3

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 8000 7000 6000 5000

4000

3000

2000

1000 900 800 700 600 500

400

300 Flow in cfs 200

100 90 80 70 60 50

10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-4

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 8000 7000 6000 5000

4000

3000

2000

1000 900 800 700 600 500

400

300 Flow in cfs 200

100 90 80 70 60 50

40 11317000 Middle Fork Mokelumne R at West Point Instantaneous Flow 30 DA 68.4 sqmi Elev 2450' Records good. Flow regulated by Middle Fork R, capacity 1,740 af and several small diversions upstream. 20 WY1912 to WY2001 1912-20, 1930-41, 1951-62 WY1965 to WY2001 10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-5

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 8000 7000 6000 5000

4000

3000

2000

1000 900 800 700 600 500

400

300 Flow in cfs 200

100 90 80 70 60 50 11317000 Middle Fork Mokelumne R at West Point 40 Instantaneous Flow DA 68.4 sqmi Elev 2450' 30 Records good. Flow regulated by Middle Fork R, capacity 1,740 af and several small diversions upstream.

20 WY1922 to WY2001 WY1922 to WY1959 WY1961 to WY1984 WY1985 to WY2001 10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-6

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 8000 7000 6000 5000

4000

3000

2000

1000 900 800 700 600 500

400

300 Flow in cfs 200

100 90 80 70 60 50

40 11317000 Middle Fork Mokelumne R at West Point Instantaneous Flow 30 DA 68.4 sqmi Elev 2450' Records good. Flow regulated by Middle Fork R, capacity 1,740 af and several small diversions upstream. 20 WY1912 to WY2001 WY1922 to WY1959 WY1964 to WY2001 10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-7

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 8000 7000 6000 5000

4000

3000

2000

1000 900 800 700 600 500

400

300 Flow in cfs 200

100 90 80 70 60 50

40 11317000 Middle Fork Mokelumne R at West Point Instantaneous Flow 30 DA 68.4 sqmi Elev 2450' Records good. Flow regulated by Middle Fork R, capacity 1,740 af and several small diversions upstream. 20 WY1912 to WY2001 WY1923 to WY1961 WY1963 to WY2001 10 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-8

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 70000 60000 50000

40000

30000

20000

10000 9000 8000 7000 6000 5000

4000

3000 Flow in cfs 2000

1000 900 800 700 600 500

400 11264500 Merced River at Happy Isle Bridge Instantaneous Flow 300 DA 181 sqmi Elev 4016.58' Records good. Small diversions upstream.

200 1916-20, 1930-41, 1951-62 WY1965 - WY2001

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-9

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 70000 60000 50000

40000

30000

20000

10000 9000 8000 7000 6000 5000

4000

3000 Flow in cfs 2000

1000 900 800 700 600 500

400 11264500 Merced River at Happy Isle Bridge Instantaneous Flow 300 DA 181 sqmi Elev 4016.58' Records good. Small diversions upstream.

200 WY1916 to WY2001 1916-20, 1930-41, 1951-62 WY1965 to WY2001

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-10

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 70000 60000 50000

40000

30000

20000

10000 9000 8000 7000 6000 5000

4000

3000 Flow in cfs 2000

1000 900 800 700 600 500

400 11264500 Merced River at Happy Isle Bridge Instantaneous Flow 300 DA 181 sqmi Elev 4016.58' Records good. Small diversions upstream.

200 WY1922 to WY2001 WY1922 to WY1959 WY1961 to WY1984 WY1985 to WY2001 100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-11

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 70000 60000 50000

40000

30000

20000

10000 9000 8000 7000 6000 5000

4000

3000 Flow in cfs 2000

1000 900 800 700 600 500

400 11264500 Merced River at Happy Isle Bridge 300 Instantaneous Flow DA 181 sqmi Elev 4016.58' Records good. Small diversions upstream. 200 WY1916 to WY2001 WY1922 to WY1959 WY1964 to WY2001 100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-12

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 70000 60000 50000

40000

30000

20000

10000 9000 8000 7000 6000 5000

4000

3000 Flow in cfs 2000

1000 900 800 700 600 500

400 11264500 Merced River at Happy Isle Bridge 300 Instantaneous Flow DA 181 sqmi Elev 4016.58' Records good. Small diversions upstream. 200 WY1916 to WY2001 WY1923 to WY1961 WY1963 to WY2001 100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-13

Recurrence Interval in Years

2 3.333 10 20 100 1000 10000 9000 11315000 Cole Ck nr Salt Springs Dam 8000 Instantaneous Flow DA 21.0 sqmi Elev 5920' 7000 Occasional pumping for summer use. 6000 WY1928 to WY2001 (exc 76) 5000 WY1928 to WY1959 WY1961 to WY1984 (exc 76) 4000 WY1985 to WY2001

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 4-14

Recurrence Interval in Years

3000

2000

1000 900

Flow in cfs 800

700

600

500

400

300

200

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probablility per Hundred Years

Figure 4-15

Recurrence Interval in Years

2 3.333 10 20 100 1000 100000 90000 80000 11413000 North Fork Yuba R blw Goodyears Bar 70000 Instantaneous Flow 60000 DA 250 sqmi Elev 2453' 50000 Records good. Small diversions upstream. 40000 WY1931 to WY2001 30000 WY1931 to WY1959 WY1961 to WY1984

20000 WY1985 to WY2001

10000 9000 8000 7000 6000 5000

4000

3000 Flow in cfs 2000

1000 900 800 700 600 500

400

300

200

100 5 2 1 60 30 10 50 40 20 95 80 99 98 90 70 0.5 0.2 0.1 99.8 99.5 99.9 Exceedence Probability per Hundred Years

Figure 4-16