Municipal Hydroelectric Project, FERC Project No
Total Page:16
File Type:pdf, Size:1020Kb
ENVIRONMENTAL ASSESSMENT FOR HYDROPOWER LICENSE Municipal Hydroelectric Project, FERC Project No. 1235-017 Federal Energy Regulatory Commission Office of Energy Projects Division of Hydropower Licensing 888 First Street, NE Washington, D.C. 20426 November 2018 TABLE OF CONTENTS TABLE OF CONTENTS ..................................................................................................... i LIST OF FIGURES ............................................................................................................ iii LIST OF TABLES.............................................................................................................. iv ACRONYMS AND ABBREVIATIONS............................................................................ v 1.0 NTRODUCTION ..................................................................................................... 1 1.1 APPLICATION ............................................................................................. 1 1.2 PURPOSE OF ACTION AND NEED FOR POWER .................................. 2 1.2.1 Purpose of Action .............................................................................. 2 1.2.2 Need for Power .................................................................................. 4 1.3 STATUTORY AND REGULATORY REQUIREMENTS ......................... 4 1.3.1 Federal Power Act .............................................................................. 4 1.3.2 Clean Water Act ................................................................................. 6 1.3.3 Endangered Species Act .................................................................... 6 1.3.4 Coastal Zone Management Act .......................................................... 7 1.3.5 National Historic Preservation Act .................................................... 8 1.4 PUBLIC REVIEW AND COMMENT ......................................................... 8 1.4.1 Scoping............................................................................................... 9 1.4.2 Interventions ...................................................................................... 9 1.4.3 Comments on the License Application .............................................. 9 2.0 PROPOSED ACTION AND ALTERNATIVES ................................................... 10 2.1 NO-ACTION ALTERNATIVE .................................................................. 10 2.1.1 Existing Project Facilities ................................................................ 10 2.1.2 Project Safety ................................................................................... 11 2.1.3 Existing Project Operation ............................................................... 11 2.1.4 Existing Environmental Measures ................................................... 13 2.2 APPLICANT’S PROPOSAL ...................................................................... 13 2.2.1 Proposed Project Facilities ............................................................... 13 2.2.2 Proposed Project Operation ............................................................. 13 2.2.3 Proposed Environmental Measures.................................................. 14 2.3 STAFF ALTERNATIVE ............................................................................ 14 2.4 ALTERNATIVES CONSIDERED BUT ELIMINATED FROM DETAILED ANALYSIS........................................................................................ 15 2.4.1 Retiring the Project .......................................................................... 15 3.0 ENVIRONMENTAL ANALYSIS ......................................................................... 17 3.1 GENERAL DESCRIPTION OF THE RIVER BASIN .............................. 17 3.2 SCOPE OF CUMULATIVE EFFECTS ANALYSIS ................................ 17 3.2.1 Geographic Scope ............................................................................ 18 3.2.2 Temporal Scope ............................................................................... 19 3.3 PROPOSED ACTION AND ACTION ALTERNATIVES ....................... 19 i 3.3.1 Geology and Soil Resources ............................................................ 20 3.3.2 Aquatic Resources ........................................................................... 22 3.3.3 Terrestrial Resources ....................................................................... 43 3.3.4 Threatened and Endangered Species ............................................... 48 3.3.5 Recreation Resources ....................................................................... 53 3.3.6 Cultural Resources ........................................................................... 58 3.4 NO-ACTION ALTERNATIVE .................................................................. 64 4.0 DEVELOPMENTAL ANALYSIS ........................................................................ 65 4.1 POWER AND ECONOMIC BENEFITS OF THE PROJECT .................. 65 4.2 COMPARISON OF ALTERNATIVES ...................................................... 66 4.2.1 No-action Alternative ....................................................................... 67 4.2.2 City’s Proposal ................................................................................. 67 4.2.3 Staff Alternative ............................................................................... 67 4.3 COST OF ENVIRONMENTAL MEASURES........................................... 68 5.0 CONCLUSIONS AND RECOMMENDATIONS ................................................. 74 5.1 COMPREHENSIVE DEVELOPMENT AND RECOMMENDED ALTERNATIVE .................................................................................................... 74 5.1.1 Measures Proposed by the City........................................................ 74 5.1.2 Additional Staff-Recommended Measures ...................................... 75 5.2 UNAVOIDABLE ADVERSE EFFECTS ................................................... 81 5.3 SUMMARY OF SECTION 10(J) RECOMMENDATIONS ..................... 81 5.4 CONSISTENCY WITH COMPREHENSIVE PLANS .............................. 85 6.0 FINDING OF NO SIGNIFICANT IMPACT ........................................................ 86 7.0 LITERATURE CITED ........................................................................................... 87 ii LIST OF FIGURES Figure 1. Location of the Little River Dam at the Municipal Hydroelectric Project No. 1235 (Source: staff)...................................................................................................... 3 Figure 2. Bathymetry of the project impoundment based on a bathymetric survey that was conducted in August 2015 while the impoundment water level was held at an elevation of 1,772.3 feet (0.3 foot above full pool). Note that elevations are color- coded, whereby greens represent the deepest locations and browns the shallowest locations as indicated in the figure legend (Source: license application, as modified by staff). ...................................................................................................................... 26 Figure 3. Example of riffle habitat located approximately 900 feet downstream of the project dam (just below the Route 605 bridge). Picture was taken on October 2, 2017, when outflow from the Municipal Project was 142 cfs (Source: staff). .......... 27 Figure 4. Length frequency distributions of common centrarchids in the project impoundment, based on boat electrofishing surveys conducted during September 2013 (“n” refers to the number of each species collected) (Source: staff). ............... 33 Figure 5. Time series of impoundment elevations (blue line) and project inflows (orange line) during the summer of 2003 (June through August), which was the wettest on record across years 1997 through 2012. Periods when the Municipal Project was peaking, denoted on the graph below, were inferred from patterns in impoundment stage data (Source: staff). ........................................................................................... 39 Figure 6. Time series of impoundment elevations (blue line) and project inflows (orange line) during the summer of 2002 (June through August), which was the driest on record across years 1997 through 2012. Based on the pattern in impoundment stage data, the project appeared to be peaking for most of this 3-month period (Source: staff). ........................................................................................................................... 40 iii LIST OF TABLES Table 1. Percent of days each month that daily impoundment fluctuations were less than 2 feet based on impoundment stage data (years 1997 through 2012) from USGS gage No. 03170500 (Source: staff). .................................................................................... 13 Table 2. Monthly project inflow statistics for years 1928 through 2017 (Source: Staff). ..................................................................................................................................... 23 Table 3. Species composition of the impoundment fish community based on boat electrofishing surveys conducted by Virginia DGIF during September 2013. For comparative purposes, species are included in this table that were not collected in the impoundment (e.g., walleye), but were collected downstream of the dam (see table 4) (Source: license application, as modified by staff). ................................................... 28 Table 4. Species composition of the fish community downstream of the dam