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PROGRESS MEMORANDUM
TO: Carolina Hernandez, P.E., Los Angeles County Public Works
PROJECT: Los Angeles River Master Plan Update
TASK NUMBERS: 3.1 and 3.2
SUBJECT: Water Resources: Flood Risk Management, Water Quality, and Water Supply
SUBMITTED BY: Mark Hanna, Ph.D., P.E., Geosyntec Jessica M. Henson, RLA, ASLA, OLIN Al Preston, Ph.D., P.E., Geosyntec Najwa Pitois, Ph.D., Geosyntec Curtis Fang, P.E., Geosyntec Nate Wooten, RA, AIA, ASLA, OLIN
DATE: 4 December 2018
MEMO NUMBER: 3.1_3.2-2
The following Progress Memorandum summarizes the significant water resources findings for Los Angeles River Master Plan Update Task 3.1 related to water quality and water supply and Task 3.2 related to flood risk management.
Executive Summary
The 51-mile Los Angeles River (herein referred as “LA River” or “river”) is an engineered channel designed in response to historic flood events to convey stormwater to the Pacific Ocean as quickly and efficiently as possible.
Flood Risk Management
As efforts continue to develop the LA River for multi-use benefits (e.g., ecosystem function, open space, parks and recreation, water quality enhancements, water supply) changes to the river must occur within the constraints of managing flood risk. This includes maintaining existing flood conveyance capacity, improving capacity in deficient reaches, accounting for climate change, and resiliency planning for mitigation/evacuation during extreme events. Most reaches of the river currently meet existing design standards for flood conveyance capacity; however, several distinct reaches do not meet those same minimum standards. Understanding the uncertainty in managing flood risk and the recent increased occurrence of extreme weather events in the United States and around the globe, resiliency planning in the case of extreme weather events within the Los Angeles River Watershed (herein referred as “watershed”) is a critical component of flood risk management.
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Water Quality
The LA River is an impaired water body with multiple total maximum daily load requirements (TMDLs) established to regulate pollutants. While over 800 water quality improvement projects are planned or have been completed within the LA River Watershed, additional efforts are needed to meet applicable water quality targets established in Enhanced Watershed Management Program/ Watershed Management Program (EWMP/WMP), which are the guidance documents for regulatory compliance. While most EWMP/WMP documents that directly impact the river’s mainstem have sufficient projects in place to meet water quality requirements, there is much uncertainty in the funding and implementation of these plans to keep pace with the approved planned milestones.
Water Supply
More than 50% of the region’s water supply is imported from the Colorado River, Sacramento-San Joaquin River Delta, and the Eastern Sierras. With increasing population, regulatory requirements, and demands on the water system accentuated by decreasing reliability in the sources of water supplies due to cyclical droughts and climate change, the LA River presents an opportunity to develop and diversify local water resources that increases the reliability and resiliency of the region’s water supply.
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Flood Risk Management
The 51-mile Los Angeles River and its nine major tributaries drain an 834 square-mile watershed (Figure 1) that consists of steep mountains, foothills, and low-laying alluvial plains. The LA River main stem is measured starting from River Mile (RM) 0 at the Pacific Ocean, up to RM 51 at the confluence of Bell Creek and Arroyo Calabasas. Approximately 62% of the LA River Watershed is developed with mixed land uses.1 Much of this development is intense urbanization almost exclusively contained on the alluvial plains. During a typical storm the most intense precipitation falls in the mountains, where it runs off the steep slopes and collects rapidly in the tributaries, before entering the main channel. Historically large run-off events resulted in the river channel substantially altering its course across the alluvial plains, resulting in large flood plains that encompassed the San Fernando Valley and much of the lower alluvial plain, including the current location of Downtown LA (Figure 2). These large events are characterized often by extreme precipitation, such as in 1862 where 30 consecutive days of rain resulted in 36 inches of rain in LA and the relocation of the LA River Mouth from Venice (in the current Ballona Creek channel) to Wilmington (near the current LA River Mouth in Long Beach). Other extreme historic precipitation events include 62 inches of rain in the mountains in 24 hours in 1889 (Figure 3).
1Los Angeles Regional Water Quality Control Board, Los Angeles Watershed. Accessed on September 20, 2018 from https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/regional_program/Water_Quality_and_Waters heds/los_angeles_river_watershed/la_summary.shtml
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Figure 1: The LA River starts from the confluence of Arroyo Calabasas and Bell Creek in Canoga Park (at RM51) and ends at the Mouth in Long Beach (RM0). The river drains an 834 square-mile watershed.
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Figure 2: Historical flooding and river paths prior to 1825.
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Figure 3: Historic flash rain and flood events in the LA River Watershed. The hydrology of the Los Angeles region is characterized by large inter-annual variability in rainfall with periods of major droughts and with often extreme precipitation events leading to major floods.
With increasing urbanization and development within the flood plain in the early 1900s, the risks and costs associated with flooding began to increase. Public outcry following floods in 1914 led to the formation of the LA County Flood Control District (LACFCD) in 1915, which took charge of developing flood management plans. Devastating floods in the 1930’s resulted in Federal funds and assistance to accelerate the pace of the program with the work being performed under the direction of the US Army Corps of Engineers.
The Flood Control Act of 1936 allocated funds to assist LA County in developing and expanding flood management infrastructure, including further channelizing 51 miles of the Los Angeles River. Construction of the channel occurred in several phases between 1936 and 1959. Subsequent
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channel improvements were made as part of the LA County Drainage Area (LACDA) project2,3,4,5,6,7 in the late 1990s to early 2000s to increase channel capacity in the lower 12 miles of the river. These improvements were motivated by the February 1980 flood that exceeded capacity of the river with slight overflow of the levees near Wardlow Road. The 1980 flood was estimated to be a 40-year event, which caused concern, since prior to that event the protection level was thought to be adequate for a 100-year event8.
Changes in flood exceedance frequencies over time may partly be attributed to the effect of urbanization and the associated increase in impervious surfaces in the watershed. However, the effect of urbanization is primarily to increase the run-off volumes for smaller, frequent storm results, with much less relative effect for the potentially devastating larger events (e.g., the 100-year event) (Figure 4) that are the primary focus of current flood risk management.
2 USACE 1991. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area Final Feasibility Final Report, December 1991. 3 USACE 1996a. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area Los Angeles River Improvements Project Including Rio Hondo and Compton Creek, Design Analysis Report No. 1. December 1996. 4 USACE 1996b. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area Los Angeles River Improvements Project Including Rio Hondo and Compton Creek, Design Memorandum No. 2. June 1996. 5 USACE 1997a. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area Design Memorandum for Los Angeles River Improvements Century Freeway to Willow Street, Final Draft Report. July 1997. 6 USACE 19967b. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area Los Angeles River Improvements Project Including Rio Hondo and Compton Creek, Design Memorandum No. 3. October 1997. 7 USACE 1999. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area Los Angeles River Improvements Project Including Rio Hondo and Compton Creek, Final Design Memorandum No. 5. June 1999. 8 USACE 2004. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area, Stormwater Management Plan, Phase 1, HEC-RAS Hydraulic Models, Rio Hondo Channel Reach 4 and Lower Los Angeles River Reaches 3B, 3A, and 2, July 2004.
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Figure 4. Effect of urbanization on flood exceedance frequency. Left frame is for non-urbanized watershed, Right frame is for urbanized watershed. Urbanization over time leads to substantial increases in discharge flow rates for smaller, frequent events, as the ability of the watershed to infiltrate water is decreased. However, the increases become proportionally smaller for larger extreme events.
Channel Physical Characteristics and Hydraulics
Today the channel consists of a mixture of trapezoidal concrete sections, rectangular concrete sections, and trapezoidal sections with soft bottom (Figure 5). The channel is predominantly trapezoidal in shape, with rectangular sections limited to the San Fernando Valley between Sherman Oaks (RM42) and Burbank (RM33) and over a 1-mile stretch near Vernon (RM18) (Figure 6). The most notable soft bottom region is in the Glendale Narrows region from RM31 to RM24, where early efforts to fully concrete the channel were thwarted by hydrostatic forces from upwelling groundwater. Other soft bottom reaches are in the Sepulveda Flood Control Basin (RM46 to RM44), and the Estuary region (RM3 to RM0) (Figure 6). If not maintained, the soft bottom reaches can become heavily vegetated, often with invasive species, and result in decreased flood conveyance capacity.
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Figure 5. Typical channel cross sections along the LA River.
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Figure 6. Channel conditions, flood conditions, and critical facilities/infrastructure (within 1 mile) along the LA River. Channel structure: orange=trapezoidal, red=rectangular, black=transitions. Channel type: red=concrete, green=soft-bottom.
The width of the channel generally increases in the downstream direction (Figure 6) to account for the increasing flow rates as run-off accumulates (e.g., see Design Discharge/Capacity in Figure 7) and/or as the channel slope decreases. Analysis of the physical channel characteristics, including width, shape, and material led to the development of 13 Hydraulic Design Reaches, A through M (Figure 6). The hydraulic and flow characteristics are generally similar within each of these reaches, although local effects (e.g., flow constrictions due to bridges) may result in alterations of the flow regime.
The hydraulics in the LA River are complex (Figure 7), with a mixture of subcritical regions (Froude number < 1 indicating slower, deeper flow) and supercritical regions (Froude number > 1 indicating faster, shallower flow). The flow is predominantly subcritical in the soft bottom portions, including the Sepulveda Flood Control Basin and the Glendale Narrows, although there are short supercritical regions in the Glendale Narrows where the channel bottom locally consists of concrete and the flow is accelerated to reduce depth under bridges.
The concreted portions of the river are predominantly supercritical, although local constrictions such as bridges cause flow to locally backup, form hydraulic jumps, and become subcritical. The flow
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regimes between RM15 and RM6 are quite variable, with alternating regions of subcritical and supercritical flow. The hydraulics in this region are likely to be particularly sensitive to changes to the channel, with small physical changes potentially resulting in substantial movement of hydraulic jump locations and associated substantial changes in flow depth. Additionally, there are several regions along the river that are hydraulically unstable (0.86 < Froude < 1.13), which may result in large and unstable surface waves. Effects of these waves are often mitigated by increasing channel height to contain the waves and/or constructing channel side-slopes with rough cobble material to reduce wave run-up.
Figure 7. Design Discharge/Capacity, Flow Depth, Flow Velocity, and Froude number in the LA River
Current Flood Risk
The efforts to channelize the LA River and tributaries to manage flood risk have been largely successful with the identified 100-year floodplain area (Figure 8) vastly reduced, and the 500-year floodplain area substantially reduced (Figure 8) compared to historical floodplains (Figure 2). Notwithstanding the overall success, there are problematic reaches along the river, and flood risk remains a real threat that must be managed and mitigated. For example, the Glendale Narrows reach (RM31 to RM24) has known deficiencies that are exacerbated by the heavy vegetation that has established itself in the soft bottom of the channel (Figure 9).
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Figure 8. Flood hazards in LA County including 100-year and 500-year floodplains, tsunami inundation areas, and sea-level-rise.
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Figure 9. Flood risk remains a real threat along the Glendale Narrows reach. Left: Recent flood plain modeling by USACE9. Right: photograph taken from Glendale Blvd Bridge.
The deficiency of the Glendale Narrows reach is illustrated by comparing channel capacity and discharges for different flood frequencies (Figure 10). Analyses indicate generally less than 50-year protection in this reach, with many regions having less than 10-year protection, and as low as 3-year protection10.
Further downstream, between Downtown LA and South Gate there is mostly a greater than 100-year protection level, although just downstream of the Arroyo Seco the protection level is only at the 77- year frequency11. Following the LACDA improvements in the late 1990s through early 2000s, the lower
9 USACE 2016. U.S. Army Corps of Engineers, Los Angeles District: Hydraulics Report, Floodplain Analysis, Los Angeles River: Barham Boulevard to First Street, Flood Plain Management Services Special Study, Los Angeles, California, October 2016. 10 USACE 2015. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles River Ecosystem Restoration Integrated Feasibility Report, FINAL Feasibility Report and Environmental Impact Statement/Environmental Impact, Report, September 2015. Appendix E, Table 17. 11 USACE 1991. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area Final Feasibility Final Report, December 1991. Plate 4.
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river has 133-year protection level. For flows greater than the 133-year event there are designed overtopping points downstream of Imperial Highway12.
Figure 10. Channel design discharge/capacity and flow rates for different flood frequency intervals.
Analysis of critical facilities and hazardous material sites (Figure 11) indicates that there are 404 total facilities/sites within the 100-year flood plain, and 4,359 total facilities/sites within the 500-year flood plain (Figure 12). Many of these are within 1-mile of the river as indicated in Figure 6.
12 USACE 19967b. U.S. Army Corps of Engineers, Los Angeles District: Los Angeles County Drainage Area Los Angeles River Improvements Project Including Rio Hondo and Compton Creek, Design Memorandum No. 3. October 1997.
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Figure 11. Flood hazards and critical facilities within LA County
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Figure 12. Flood hazards and critical facilities infrastructure
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Water Quality
The LA River Watershed encompasses 834 square miles (Figure 13). Two-hundred seven square miles of the watershed are considered as subwatersheds that drain directly into the mainstem of the river without first entering into major regulated tributary rivers13 (herein referred as “direct subwatershed”). Designated beneficial uses of waterbodies in the watershed were established in the Los Angeles Regional Water Quality Control Board Basin Plan (Basin Plan)14. Appropriate water quality objectives were subsequently established to ensure the protection of such beneficial uses. 24 beneficial uses were established in the Basin Plan, 18 beneficial uses were identified for waterbodies in the watershed. Beneficial uses that have been attained for a waterbody on or after November 28, 1975 were considered existing beneficial uses. In comparison, beneficial uses were designated as “potential” if there is plan, potential or public desire to put the water to such future use.
As discussed above, approximately 62% of the LA River Watershed is developed with mixed land uses.15 Pollutants typically generated from the land use activities, as summarized in Table 1, can be mobilized by dry and wet weather runoff and transported into the river, leading to degraded water quality and creating negative impacts on the aquatic ecosystem as well as human use of the waterway. Many water bodies in the watershed, including the LA River itself, are classified as impaired waters by the Clean Water Act16 and require “treatment” to support their designated beneficial uses established in the Basin Plan.
13 Such as Tujunga Wash, Arroyo Seco, the Rio Hondo, and others. 14 Los Angeles Regional Water Quality Control Board, Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties. Accessed on November 30, 2018 from https://www.waterboards.ca.gov/losangeles/water_issues/programs/basin_plan/basin_plan_documentation.ht ml 15Los Angeles Regional Water Quality Control Board, Los Angeles Watershed. Accessed on September 20, 2018 from https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/regional_program/Water_Quality_and_Waters heds/los_angeles_river_watershed/la_summary.shtml 16 State Water Resources Control Board, Impaired Water Bodies, Accessed on September 20, 2018 from https://www.waterboards.ca.gov/losangeles/water_issues/programs/303d/index.html
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Figure 13: Cumulative total and direct tributary areas of the Los Angeles River. Data is derived from the County of Los Angeles LSPC model input.
Table 1: Common pollutants associated with land use types17 Land Use Type Typical Pollutants Residential Bacteria, Nutrients (Nitrogen, Phosphorus), Trash, Pesticides, Commercial Oil and Grease, Trash Transportation Trace Metals (Copper, Zinc, Lead), Suspended Solid, Volatile Organic Compounds Industrial Trace metals (Copper, Zinc, Lead), Bacteria, Suspended Solid, PCBs, DDTs,
During the development of the County of Los Angeles-led Integrated Regional Water Management Plan (IRWMP) in 2014, water quality modeling was conducted to prioritize areas with significant water quality concerns in the watershed. Subsequently adapted for this effort, the resultant water quality
17 Geosyntec Consultants, A User’s Guide for the Structural BMP Prioritization and Analysis Tool, accessed on September 2018 from http://www.sbpat.net/downloads/SBPAT_UserGuide_FINAL.pdf
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priority mapping represents an integrated evaluation of dry and wet-weather drainage quality compared to impaired receiving water bodies, their identified beneficial uses and impairments, and land use-based pollutant loading rates18(Figure 14).
Figure 14: Water quality priority mapping adapted from 2014 IRWMP
In an effort to restore impaired water bodies, Section 303(d) of the Clean Water Act established Total Daily Maximum Loads (TMDLs), a regulatory item that sets the maximum pollutant allowed to be discharged into an impaired water body. The river is subject to five TMDLs that collectively regulate discharges of 13 pollutants. TMDL targets are established based on pollutant source assessments, as well as human health and ecosystem toxicity analyses. As a result, TMDL targets vary spatially and temporally throughout the river.
Considerable resources from the public and private sectors have been dedicated to improve the water quality within impaired water bodies in the LA River Watershed. Over 800 water quality improvement
18 County of Los Angeles Department of Public Works, IRWMP Appendix F: GLAC IRWMP Water Quality Objectives and Targets. Accessed on September 20 2018 from http://dpw.lacounty.gov/wmd/irwmp/docs/2014%20Public%20IRWMP%20Update/17.%20App- F%20Water%20QualityTM%20FINAL.pdf
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projects are planned, in development, under construction, and/or have been in operation within the watershed to date (Figure 15). The purpose of water quality improvement projects is to capture stormwater and urban runoff for treatment, infiltration, direct use, or discharged to the receiving waters. Water quality improvement projects vary in size and targeted pollutants. They range from regional stormwater retention facilities that can treat up to hundreds of acres of tributary area, to local bioretention planters that are sized to capture and treat stormwater generated on a single parcel. Collectively, water quality improvement projects contribute toward TMDL compliance established in the watershed.
Figure 15: Water quality projects in the Los Angeles River Watershed.
Aiming at a more holistic and effective approach for addressing water quality issues, the 2012 Los Angeles County MS4 Permit allowed permittees to collaboratively develop WMP or EWMP to facilitate watershed-wide implementation strategies for TMDL compliance. Through watershed-specific water quality priority identification and modeling-based reasonable assurance analyses, each EWMP/WMP outlines an implementation plan that includes structural and non-structural best management practices (BMP) necessary to achieve applicable water quality targets. The watershed is subject to one EWMP (Upper Los Angeles River Watershed EWMP) and two WMPs (Los Angeles River Upper Reach 2 WMP and Lower Los Angeles River WMP). The three plans established structural BMP implementation targets in terms of static volume retention for each subwatershed. Utilizing the EWMP/WMP
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implementation targets and the project database developed in Task 2 of the LARMP Update, the EWMP/WMP capacity targets and capacity achieved within the 207 square miles of the direct subwatersheds19 were aggregated to create the EWMP/WMP target ruler (Figure 16). Although it can be shown that planned and/or completed projects help to nearly meet the requirements set forth in the 2012 MS4 permit, there is much uncertainty in the funding and implementation of these plans to keep pace with the approved planned milestones.
Figure 16: Comparison between total EWMP/WMP capacity targets and targets achieved by already planned or completed projects to-date. Additional water quality improvement projects are needed in some locations to meet the capacity targets.
19 As defined previously, direct subwatershed refers to those tributary areas that flow into the mainstem of the river without entering major regulated upstream tributaries such as the Tujunga Wash, Arroyo Seco, the Rio Hondo, and others.
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Water Supply
Water is a scarce and valuable resource in Southern California. More than 50% of the region’s water supply is imported from the Colorado River, Sacramento-San Joaquin River Delta, and the Eastern Sierras.20 In the Los Angeles Basin, the sources of water supply are comprised of 57% from imported water, 34% from groundwater, and 9% sourced from recycled water, water conservation measures, and local surface water diversions.21 There is a regional desire by the major water suppliers in the greater Los Angeles Basin to increase reliability by improving local water supply.22,23,24,25,26 Local water supply sources include groundwater, recycled water, and stormwater. With increasing population, regulatory requirements, and demands on the water system accentuated by decreasing reliability in the sources of water supplies due to cyclical droughts and climate change, it is crucial to diversify and develop local water resources strategies that increase the reliability and resiliency of the region’s water supply.
Hydrology
The Los Angeles River drains an 834-square mile watershed. Rainfall exhibits both inter-annual and intra-annual variability with mean annual rainfall depths varying between 13 inches in the lower reaches and 39 inches in the mountains. The wettest months of the year occur between October and April, as is typical of Mediterranean climates (Figure 17).
20 The Metropolitan Water District of Southern California, 2015, Urban Water Management Plan 21 U.S. Department of the Interior Bureau of Reclamation, County of Los Angeles Department of Public Works Los Angeles County Flood Control District, November 2016, Los Angeles Basin Study 22 ibid 23 Mayoral Executive Directive No. 5, October 2014, Emergency Drought Response – Creating a Water Wise City 24 Los Angeles Department of Water and Power, 2015, Urban Water Management Plan 25 Water Replenishment District of Southern California, 2016, Groundwater Basins Master Plan 26 Los Angeles County Department of Public Works, 2014, The Greater Los Angeles County Region Integrated Regional Water Management Plan Update
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Figure 17: Annual and seasonal precipitation variability in the LA River Watershed
As shown in Figure 18, hydrologic drivers in the LA River Watershed are numerous: inputs to the Los Angeles River are comprised of wet weather runoff originating in the mountains and flatlands and dry weather inputs from incidental dry weather urban runoff, groundwater upwelling in the soft bottom reaches, and effluent discharge from the Donald C. Tillman Water Reclamation Plant (DCTWRP), Los Angeles Glendale Water Reclamation Plant (LAGWRP), and Burbank Water Reclamation Plant (BWRP). Beneficial use includes demand from the underlying groundwater basins, namely the groundwater basins managed by the Upper Los Angeles River Area (ULARA) and the Water Replenishment District of Southern California (WRD), habitat in the Glendale Narrows region, significant bird habitat in the lower reaches between RM 9 and 3, and recreation in several locations including the Sepulveda Basin and Glendale Narrows.
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Figure 18: Hydrologic drivers in the LA River Watershed
Dry Weather Flows
Inflows to the river consist of dry weather and wet weather flows. Dry weather inflows are comprised of incidental urban runoff entering the river through storm drain outfalls, flows from the three WRPs, and groundwater upwelling. Dry weather outflows consist of evaporation and evapotranspiration (ET) as shown in Figure 19. The assumptions on possible existing dry weather flow were based on the One Water LA 2040 Plan Volume 8 Technical Support Materials and updated for the LARMP Update process.27 Dry weather inflows from DCTWRP and LAGWRP were assumed to be 42.0 cfs at RM 43 and 12.1 cfs at RM 30, respectively, based on the 10th percentile of daily average total effluent flow between 2013 and 2015. Dry weather inflow from BWRP was assumed to be 7.0 cfs at RM 32 based on the National Pollutant Discharge Elimination System (NPDES) Permit CA0055531. Groundwater upwelling was assumed as 5.6 cfs applied evenly throughout the soft bottom reach based on the 11- year annual average (WY2002-03 – WY2012-13).28,29 Incidental urban runoff was assumed to be 84 gallons per day per impervious acre (gpd/imp ac) based on monitoring from 12 low flow diversions
27 City of Los Angeles, October 2017, One Water LA 2040 Plan, Volume 8 – Technical Support Materials, Final. 28 City of Los Angeles, October 2017, One Water LA 2040 Plan, Volume 4 – LA River Flow Study, Final. 29 Water Replenishment District of Southern California, ULARA 2014, Water Year 2012-2013 Watermaster Report
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that the City of Los Angeles operates. Finally, evaporation was applied along the entire length of the river while ET was applied in the reaches where riparian vegetation exists. Evaporation and ET values were based on the Los Angeles County LSPC model’s potential ET values, which are based on conversion of computed National Climatic Data Center (NCDC) evaporation pan data from Long Beach Airport (Gage 23129) and Burbank-Glendale-Pasadena (Gage 23152) using pan coefficients of 0.74- 0.78. This equates to a composite ET of 0.50 inches per day (in/d) for reaches upstream of RM 24 and 0.41 in/d for reaches downstream of RM 24. This analysis estimates existing dry weather flow as 51,000 acre-feet per year (AFY) at the mouth of the river (Figure 19). Note that the RM markers on the horizontal axis represent one-mile intervals with RM 51 and RM1 representing RM51- RM50 and RM1-RM0, respectively.
Figure 19: Estimated existing dry weather flow in the LA River
In recent years, agencies and municipalities have expressed intent to increase reuse of water treated at WRPs that currently discharge effluent into the LA River, as well as to manage groundwater upwelling and urban runoff. Combined, these actions could change the current beneficial uses of the existing dry weather flow regime within the river. In response to this challenge, the State Water Resources Control Board along with the Los Angeles Regional Water Quality Control Board (together, “the Water Boards”), both of which support maximizing the use of recycled water and protecting
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beneficial uses, has embarked on a multi-year study (currently in first year) to develop an approach to balancing the impact of dry weather flow diversions with the identified beneficial uses.
Upon review of the dry weather inputs, and their potential for reductions in the future, it is conceivable that the current dry weather flow regime could approach zero. A Possible future dry weather flow scenario was estimated by assuming that all three WRPs recycle 100% of their effluent, groundwater upwelling is reduced by 50%, urban dry weather urban runoff is reduced by 50% from a partial implementation of the EWMPs and WMPs by 2038, and ET increases by 25%. This results in a possible future dry weather flow of 1,000 AFY at the mouth of the river (Figure 20).
Figure 20: Estimated possible future dry weather flow in the LA River
Understanding the current Water Boards’ process for developing the future low flow regime, a plausible future dry weather flow scenario was estimated by assuming that two-thirds (28 cfs or 67%) of existing effluent from the DCTWRP is used to recharge groundwater and the same reduction of 67% is applied to the effluent flowrates from LAGWRP and BWRP resulting in 4 cfs released from LAGWRP and 2.3 cfs released from BWRP. It was also assumed that groundwater upwelling is eliminated due to it being managed by the Los Angeles Department of Water and Power (LADWP) and dry weather urban runoff ceases due to implementation of the EWMPs and WMPs by 2038. This results in a possible
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future dry weather flow of 10,000 AFY at the mouth of the river – an 80% reduction in the estimated existing dry weather flow (Figure 21).
Figure 21: Estimated plausible future dry weather flow in the LA River
Wet Weather Flow
Wet weather flows were estimated using the Los Angeles County Watershed Model for the Loading Simulation Program in C++ (LSPC), developed by Los Angeles County Department of Public Works (LACDPW)30 and adapted for LADWP’s Stormwater Capture Master Plan (SCMP)31, and One Water LA.32 Comparison of modeled flow volumes with USGS gage 11103000 at Los Angeles River above Long Beach for the period of available overlapping record (WY1989 - WY1992) indicates modeled
30 Los Angeles County Department of Public Works, 2010, Los Angeles County Watershed Model Configuration and Calibration—Part I: Hydrology. 31 Los Angeles Department of Water and Power (LADWP), 2015, Stormwater Capture Master Plan. 32 City of Los Angeles Sanitation and LADWP, April 2018, One Water LA 2040 Plan, Volume 4 – LA River Flow Study Final Draft.
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annual flow volumes are typically within approximately 1% of measured annual flow volumes (LACDPW, 2010, Figure 8433).The annual runoff volumes at the mouth of the LA River were extracted from the model by quantifying the total precipitation over the LA River Watershed and the contributing flows from each portion of the watershed for each water year (WY) between 1988 and 2011. The wettest year was WY 2005 (October 1, 2004 through September 30, 2005) resulting in a discharge volume of 950,000 AF at the mouth and the driest year was WY 2007 (October 1, 2006 through September 30, 2007) resulting in a discharge volume of 51,000 AF at the mouth (Figure 22). It is notable to mention that the driest year discharge volume is comparable to average dry weather runoff at the mouth.
Figure 22: Wet weather flows at the mouth of the LA River
Groundwater Basins
Local groundwater basins are unique and valuable resources that play a critical role in the management of local water resources. Groundwater development has multiple water supply and level-
33 Los Angeles County Department of Public Works, 2010, Los Angeles County Watershed Model Configuration and Calibration—Part I: Hydrology.
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of-service benefits including reduction of imported water through increased local water supply, flexibility to adjust the resource mix within an integrated water strategy, and improved water system resiliency through access to underground storage and contingency reserves during droughts or emergencies. Local groundwater basins offer reliable water storage of recycled water and captured stormwater, as well as natural replenishment during wet years.
The ULARA Watermaster manages the four groundwater basins overlying the ULARA, which are the San Fernando Basin (SFB), Sylmar Basin, Verdugo Basin, and Eagle Rock Basin. One of the key challenges in the ULARA is the need to increase recharge into the local groundwater basins due to historical over-pumping, particularly in the SFB. The figure below shows the cumulative change in storage in the SFB since the beginning of safe yield operation implemented by the Superior Court for the County of Los Angeles (Court) in the Fall of 1968 in an effort to stop the overdraft of the SFB that began in 1954. The State Water Resources Control Board’s Division of Water Rights established a regulatory requirement of 360,000 AF for groundwater storage, which considered wet and dry cycles, operational flexibility, and annual pumping based on the calculated safe yield. It established an upper regulatory storage limit of 210,000 AF above the 1954 storage level to prevent excess groundwater from rising and leaving the basin and a lower regulatory storage limit of 150,000 AF below the 1954 storage level to allow for additional storage space in wet years. The graph also tracks the cumulative change in groundwater storage (blue area) since 1968 and shows that there has been an overall declining trend in groundwater storage since 1980 (Figure 23). This decline can be attributed to several factors including pumping in excess of long-term recharge, decrease in natural recharge caused by increased urbanization and runoff leaving the basin, and a decrease in stormwater spreading. In 2016, the available storage space in the SFB is approximately 600,000 AF34.
34 Upper Los Angeles River Area, December 2017, Annual Watermaster Report, 2015-16 Water Year
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Figure 23: Cumulative change in storage in the San Fernando Basin
LACDPW and LADWP jointly operate spreading basins in the northeastern portion of the SFB, downstream of Pacoima, Big Tujunga, and Hansen Dams, with the goal of partially offsetting the increase in runoff due to urbanization. The long-term average amount of spreading operations in the SFB is 30,000 AFY (Figure 24 and Table 2).
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Figure 24: Annual spreading operations in the San Fernando Basin
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Table 2: Annual spreading operations in the San Fernando Basin (from Figure 24 above)35 Rainfall Los Angeles County Department of Public Works (Native + City of Los Angeles (Imported) GRAND City of Burbank 1 (inches) Water Imported ) (acre-feet) (acre-feet) TOTAL (Imported)1 Weighted Year (acre- Pacoima (acre- Average Branford Hansen Lopez Pacoima Tujunga TOTAL feet) Headworks Tujunga TOTAL feet) Valley/Mtns 2015-16 547 1,137 42 1,298 523 3,548 0 0 0 3,548 306 10.05 2014-15 529 922 1 1,254 268 2,974 0 1 1 2,975 150 12.68 2013-14 474 1,667 661 7,442 195 10,439 0 4 4 10,443 7,000 7.98 2012-13 570 1,758 501 7,015 927 10,771 0 11 11 10,782 6,703 8.72 2011-12 529 9,357 104 3,482 101 13,573 0 4 4 13,577 1,371 11.55 2010-11 690 19,064 3,922 24,164 31,476 79,316 0 4 4 79,320 11,187 25.21 2009-10 535 16,766 274 9,080 12,849 39,504 0 7,509 7,509 47,013 34 20.55 2008-09 706 0 1 2,000 7,233 9,940 0 0 0 9,940 --- 12.58 2007-08 570 10,517 634 5,025 4,892 21,638 0 0 0 21,638 --- 17.27 2006-07 532 5,762 44 436 1,200 7,974 0 0 0 7,974 --- 5.36 2005-06 576 20,840 958 7,346 14,895 44,615 0 0 0 44,615 --- 17.42 2004-05 1,448 33,301 940 17,394 21,115 74,198 0 0 0 74,198 --- 45.66 2003-04 444 6,424 144 1,731 1,322 10,065 0 0 0 10,065 --- 12.21 2002-03 932 9,427 518 3,539 1,914 16,330 0 0 0 16,330 --- 21.22 2001-02 460 1,342 0 761 101 2,664 0 0 0 2,664 --- 6.64 2000-01 562 11,694 172 3,826 1,685 17,939 0 0 0 17,939 --- 22.29 1999-00 468 7,487 578 2,909 2,664 14,106 0 0 0 14,106 --- 16.77 1998-99 547 8,949 536 696 3,934 14,662 0 0 0 14,662 --- 10.83 1997-98 641 28,129 378 20,714 11,180 61,042 0 77 77 61,119 --- 38.51 1996-97 415 9,808 724 5,768 6,406 23,121 0 51 51 23,172 --- 17.65 1995-96 345 8,232 363 4,532 7,767 21,239 0 0 0 21,239 --- 14.48 1994-95 585 35,137 1,086 14,064 18,236 69,108 0 0 0 69,108 --- 33.08 1993-94 462 12,052 182 3,156 4,129 19,981 0 0 0 19,981 --- 11.86 1992-93 389 26,186 1,312 17,001 19,656 64,544 114 0 114 64,658 --- 41.26 1991-92 653 15,461 1,094 12,914 9,272 39,394 230 0 230 39,624 --- 32.39 1990-91 509 11,489 241 3,940 2,487 18,666 52 0 52 18,718 --- 7.69 1989-90 327 2,029 90 1,708 0 4,154 0 0 0 4,154 --- 9.55 1988-89 255 3,844 308 1,306 0 5,713 0 0 0 5,713 --- 9.72 1987-88 352 17,252 1,037 4,520 0 23,161 0 0 0 23,161 --- 21.36 1986-87 0 7,311 141 467 0 7,919 0 33 33 7,952 --- 7.7 1985-86 290 18,188 1,735 6,704 0 26,917 0 1,433 1,433 28,350 --- 23.27 1984-85 244 13,274 104 3,375 0 16,997 0 5,496 5,496 22,493 --- 13.31 1983-84 213 10,410 0 3,545 0 14,168 0 24,115 24,115 38,283 --- 11.18 1982-83 883 35,192 1,051 22,972 10,580 70,678 10 32,237 32,247 102,925 --- 46.07 1981-82 345 14,317 243 5,495 0 20,400 3,853 0 3,853 24,253 --- 20.16 1980-81 245 14,470 335 3,169 0 18,219 4,652 9,020 13,672 31,891 --- 12.89 1979-80 397 31,087 1,097 15,583 0 48,164 5,448 19,931 25,379 73,543 --- 33.66 1978-79 295 24,697 1,018 12,036 0 38,046 2,463 31,945 34,408 72,454 --- 24.07 1977-78 2,142 28,123 445 20,472 12,821 64,003 3,200 18,247 21,447 85,450 --- 44.84 1976-77 377 2,656 63 1,943 0 5,039 3,142 16 3,158 8,197 --- 16.02 1975-76 470 3,128 562 1,308 0 5,468 3,837 5,500 9,337 14,805 --- 14.2 1974-75 681 5,423 915 2,476 0 9,495 4,070 9,221 13,291 22,786 ------1973-74 672 6,287 946 2,378 0 10,283 6,205 0 6,205 16,488 ------1972-73 1,271 9,272 0 6,343 2,274 19,160 5,182 0 5,182 24,342 ------1971-72 161 1,932 0 1,113 0 3,206 7,389 0 7,389 10,595 ------1970-71 507 11,657 727 4,049 0 16,940 6,804 399 7,203 24,143 ------1969-70 674 11,927 0 1,577 2,380 16,558 11,021 0 11,021 27,579 ------1968-69 461 32,464 893 14,262 13,052 61,132 6,698 3,676 10,374 71,506 ------AVG. 552 13,647 587 6,851 5,034 26,671 1,653 3,754 5,407 32,078 4,824 1Spreading by Burbank began in 2009-10 Water Year following completion of the Burbank MWD connection. These volumes are reported by LACDPW spreading data, and are therefore included in the “Grand Total” column.
35 ibid
Progress Memorandum to Carolina Hernandez 4 December 2018 Page 33
WRD manages the Central Basin (CB) and West Coast Basin (WCB), which overlie the reaches of the LA River downstream of downtown LA. Prior to the 1960s, extractions from both groundwater basins exceeded natural replenishment resulting in declining groundwater levels and seawater intrusion into the WCB. As a result, both basins were adjudicated to limit the amount of annual groundwater extraction: The CB was adjudicated in 1965 and established an Allowable Pumping Allocation (APA) of 217,367 AFY. The WCB was adjudicated in 1961 and allows for extraction of 64,468.25 AFY. These pumping rights are based on historical use and not safe yield of the basins. To allow pumping in excess of natural safe yield (173,400 AF), WRD and its partners replenish water artificially through surface spreading, injection at seawater barrier injection wells, and through the District’s In-Lieu Program, and charge pumpers a Replenishment Assessment (RA) to cover the replenishment costs in both basins. The sources for replenishment water are recycled water provided by the Sanitation Districts of Los Angeles County (SDLAC), West Basin Municipal Water District (WBMWD), and Los Angeles Sanitation Bureau (LASAN); imported water provided by the Metropolitan Water District of Southern California (MWD); and in-lieu water. WRD in partnership with LACDPW recharges groundwater through surface spreading in the Montebello Forebay Spreading Grounds, within the unlined portion of the San Gabriel River, and behind the Whittier Narrows Dam in the Whittier Narrows Reservoir. The long-term replenishment volume averages 130,000 AFY, of which 50,000 AFY is local water consisting of stormwater and river base flow (Figure 25 and Table 3). WRD also injects water at the three seawater intrusion barriers, that are owned and operated by LACDPW, which consist of the West Coast Basin Barrier Project (WCBBP), the Dominguez Gap Barrier Project (DGBP), and the Alamitos Barrier Project (ABP). The long-term average amount of replenishment water used for injection is 30,000 AFY (Figure 25 and Table 3). Additionally, WRD has an In-Lieu Program that provides an alternative means for replenishing groundwater by encouraging basin pumpers to purchase imported water when available instead of pumping. Historically, the majority of the water has been provided by MWD’s seasonal discounted water, but this has been suspended since 2011 due to lack of surplus supplies caused by drought and other factors. There remain, however, a few local projects within the City of Long Beach. The long-term average of In-Lieu water is 19,000 AFY (Figure 26 and Table 4).36
36 Water Replenishment District of Southern California, 2018, Engineering Survey and Report 2016/17 Water Year.
Progress Memorandum to Carolina Hernandez 4 December 2018 Page 34
Figure 25: Historical amounts of water recharged in the Montebello Forebay Spreading Grounds
Progress Memorandum to Carolina Hernandez 4 December 2018 Page 35
Table 3: Historical amounts of water recharged in the Montebello Forebay spreading grounds (in acre-feet)(a) (from Figure 25 above)37
Imported Water Recycled Water Local Water Make-up Water Water USGVM LACFCD Whittier San Jose Pomona Stormwater & Total Year WRD Total Total WD & CBMWD Total or Other WRP Creek WRP WRP River Baseflow SGVMW 1959-60 80,900 80,900 - - 20,064 100,964 1960-61 80,800 67,000 147,800 - - 9,118 156,918 1961-62 39,500 168,622 208,122 1,178 1,178 39,548 248,848 1962-63 4,800 75,790 80,590 12,405 12,405 14,565 107,560 1963-64 - 104,900 104,900 13,258 13,258 9,992 128,150 1964-65 75,500 84,670 160,170 14,528 14,528 13,097 187,795 1965-66 67,800 53,900 121,700 15,056 15,056 45,754 6,500 6,500 189,010 1966-67 74,100 10,200 84,300 16,223 16,223 59,820 160,343 1967-68 66,600 28,800 95,400 18,275 18,275 39,760 153,435 1968-69 12,500 5,300 17,800 13,877 13,877 119,395 151,072 1969-70 25,800 43,100 68,900 17,158 17,158 52,917 138,975 1970-71 46,700 25,400 72,100 19,494 3,232 22,726 44,757 - 139,583 1971-72 - 34,400 34,400 17,543 4,456 21,999 17,688 - 74,087 1972-73 - 71,947 71,947 13,622 8,327 5,937 27,886 45,077 - 20,000 20,000 164,910 1973-74 - 68,237 68,237 13,385 7,064 3,003 23,452 29,171 - 23,921 23,921 144,781 1974-75 - 71,900 71,900 14,650 6,549 5,592 26,791 29,665 --- 128,356 1975-76 - 50,800 50,800 12,394 9,062 6,231 27,687 22,073 --- 100,560 1976-77 - 9,300 9,300 10,158 12,705 6,496 29,359 19,252 14,500 6,900 21,400 79,311 1977-78 - 39,900 39,900 13,104 5,997 6,621 25,722 147,317 7,800 - 7,800 220,739 1978-79 - 65,300 65,300 10,716 11,741 6,403 28,860 68,859 --- 163,019 1979-80 - 10,200 10,200 14,568 9,815 5,023 29,406 106,820 10,900 - 10,900 157,326 1980-81 3,300 28,700 32,000 11,464 14,645 5,613 31,722 50,590 31,500 - 31,500 145,812 1981-82 - 4,600 4,600 14,133 15,285 4,634 34,052 47,930 30,900 - 30,900 117,482 1982-83 - 2,000 2,000 12,818 4,217 5,735 22,770 126,076 8,900 - 8,900 159,746 1983-84 - 1,500 1,500 13,194 14,590 4,457 32,241 60,710 20,800 - 20,800 115,251 1984-85 - 40,600 40,600 12,905 14,093 4,380 31,378 39,099 --- 111,077 1985-86 - 21,500 21,500 13,827 11,487 3,965 29,279 66,966 --- 117,745 1986-87 - 49,200 49,200 15,280 20,041 2,655 37,976 27,613 - 6,500 6,500 121,289 1987-88 - 23,300 23,300 14,585 27,182 1,582 43,349 50,068 5,800 - 5,800 122,517 1988-89 - 50,300 50,300 13,830 33,327 2,616 49,773 17,096 6,500 - 6,500 123,669 1989-90 - 52,700 52,700 15,043 33,498 1,568 50,109 9,388 13,600 - 13,600 125,797 1990-91 - 56,300 56,300 13,841 38,603 1,420 53,864 35,717 100 - 100 145,981 1991-92 - 43,100 43,100 12,620 31,326 2,957 46,903 136,357 --- 226,360 1992-93 - 16,561 16,561 11,026 29,811 8,027 48,864 147,699 --- 213,124 1993-94 - 20,411 20,411 10,249 40,768 2,965 53,981 55,896 --- 130,288 1994-95 - 21,837 21,837 10,642 18,431 4,228 33,300 100,578 --- 155,715 1995-96 - 18,012 18,012 9,971 40,922 2,969 53,862 62,920 --- 134,794 1996-97 - 22,738 22,738 9,850 36,977 3,132 49,959 58,262 --- 130,959 1997-98 - 952 952 8,378 26,483 2,156 37,017 96,706 --- 134,675 1998-99 --- 10,968 34,782 1,451 47,201 32,013 --- 79,214 1999-00 - 45,037 45,037 8,950 30,481 3,839 43,270 20,607 --- 108,914 2000-01 - 23,451 23,451 8,253 35,165 2,925 46,343 39,725 --- 109,519 2001-02 - 41,268 41,268 8,474 50,194 1,928 60,596 18,607 (c) -- 120,471 2002-03 - 17,297 17,297 5,156 35,320 2,320 42,796 63,271 (d) -- 123,364 2003-04 - 27,520 27,520 (e) 8,195 34,033 2,697 44,925 30,467 --- 102,912 2004-05 - 25,296 25,296 (e) 6,741 20,547 2,215 29,503 148,674 --- 203,473 2005-06 - 33,229 33,229 8,868 30,180 2,973 42,022 60,377 --- 135,628 2006-07 - 40,214 40,214 7,334 34,823 2,882 45,039 11,495 --- 96,748 2007-08 1,510 - 1,510 (b) 6,212 29,131 4,424 39,767 54,518 --- 95,795 2008-09 --- 5,202 29,999 4,410 39,611 35,348 --- 74,959 2009-10 - 26,286 26,286 5,431 45,538 4,762 55,731 35,398 --- 117,415 2010-11 - 37,315 37,315 7,576 24,323 5,231 37,131 113,295 --- 187,741 2011-12 --- 7,558 43,479 4,760 55,797 36,155 --- 91,952 2012-13 --- 7,004 47,207 4,933 59,145 6,048 --- 65,193 2013-14 --- 7,733 43,556 4,357 55,646 0 --- 55,646 2014-15 - 18,515 18,515 4,811 35,737 3,802 44,349 15,892 --- 78,757 2015-16 - 23,961 23,961 6,480 48,529 2,802 57,811 14,183 (f) -- 95,956 2016-17 - 32,693 32,693 6,956 47,761 3,350 58,067 70,027 (g) -- 160,786 Total 579,810 1,956,059 2,535,869 623,150 1,223,731 184,114 2,030,995 2,950,480 157,800 57,321 215,121 7,732,466 Average 44,601 38,354 47,847 11,128 27,194 3,917 36,268 50,870 13,150 14,330 14,341 133,318 (a) Includes the Rio Hondo Spreading Grounds, Whitter Narrows Conservation Pool, San Gabriel Spreading Grounds and unlined San Gabriel River below Station F263. (b) CBMWD purchased 1,510 af of imported water for spreading for Downey, Lakewood, and Cerritos. (c) Includes 1,607 af of EPA extracted groundwater from WNOU considered lower area reaplenishment water paid for by WRD in 2003. (d) Includes 5,069 af of EPA extracted groundwater from WNOU considered lower area replenishment water paid for by WRD in June 2005. (e) Includes 13,000 af of water banked by Long Beach under a storage agreement with WRD (792 af 02/03, 12,210 af 3/04). (f) Includes 206 af of DTSC extracted groundwater from WNOU considered lower area replenishment water paid for by WRD in 2017.
37 ibid
Progress Memorandum to Carolina Hernandez 4 December 2018 Page 36
Figure 26: Historical amounts of replenishment water for Central and West Coast Basins
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Table 4: Historical amounts of replenishment water for Central and West Coast Basins (in-acre-feet) (from Figure 26 above)38 Montebello Forebay Spreading Water Injection Water* In-lieu Water Imported Recycled Makeup Imported Recycled Total Year Local Water Total Total Total Water Water Water Water Water 1959-60 80,900 - 20,064 - 100,964 3,700 - 3,700 104,664 1960-61 147,800 - 9,118 - 156,918 4,420 - 4,420 161,338 1961-62 208,122 1,178 39,548 - 248,848 4,460 - 4,460 253,308 1962-63 80,590 12,405 14,565 - 107,560 4,150 - 4,150 111,710 1963-64 104,900 13,258 9,992 - 128,150 10,450 - 10,450 138,600 1964-65 160,170 14,528 13,097 - 187,795 35,780 - 35,780 223,575 1965-66 121,700 15,056 45,754 6,500 189,010 47,760 - 47,760 745 237,515 1966-67 84,300 16,223 59,820 - 160,343 46,450 - 46,450 851 207,644 1967-68 95,400 18,275 39,760 - 153,435 43,790 - 43,790 850 198,075 1968-69 17,800 13,877 119,395 - 151,072 40,730 - 40,730 850 192,652 1969-70 68,900 17,158 52,917 - 138,975 33,220 - 33,220 900 173,095 1970-71 72,100 22,726 44,757 - 139,583 35,380 - 35,380 881 175,844 1971-72 34,400 21,999 17,688 - 74,087 40,100 - 40,100 756 114,943 1972-73 71,947 27,886 45,077 20,000 164,910 40,920 - 40,920 901 206,731 1973-74 68,237 23,452 29,171 23,921 144,781 41,510 - 41,510 901 187,192 1974-75 71,900 26,791 29,665 - 128,356 36,030 - 36,030 400 164,786 1975-76 50,800 27,687 22,073 - 100,560 44,250 - 44,250 400 145,210 1976-77 9,300 29,359 19,252 21,400 79,311 48,430 - 48,430 400 128,141 1977-78 39,900 25,722 147,317 7,800 220,739 39,400 - 39,400 16,131 276,270 1978-79 65,300 28,860 68,859 - 163,019 33,600 - 33,600 18,378 214,997 1979-80 10,200 29,406 106,820 10,900 157,326 36,660 - 36,660 14,961 208,947 1980-81 32,000 31,722 50,590 31,500 145,812 33,840 - 33,840 23,823 203,475 1981-82 4,600 34,052 47,930 30,900 117,482 33,900 - 33,900 18,883 170,265 1982-83 2,000 22,770 126,076 8,900 159,746 43,240 - 43,240 19,752 222,738 1983-84 1,500 32,241 60,710 20,800 115,251 38,080 - 38,080 41,740 195,071 1984-85 40,600 31,378 39,099 - 111,077 36,080 - 36,080 36,840 183,997 1985-86 21,500 29,279 66,966 - 117,745 29,830 - 29,830 26,132 173,707 1986-87 49,200 37,976 27,613 6,500 121,289 36,430 - 36,430 29,202 186,921 1987-88 23,300 43,349 50,068 5,800 122,517 35,310 - 35,310 28,411 186,238 1988-89 50,300 49,773 17,096 6,500 123,669 31,860 - 31,860 25,425 180,954 1989-90 52,700 50,109 9,388 13,600 125,797 30,125 - 30,125 29,151 185,073 1990-91 56,300 53,864 35,717 100 145,981 27,891 - 27,891 22,039 195,911 1991-92 43,100 46,903 136,357 - 226,360 33,246 - 33,246 19,104 278,710 1992-93 16,561 48,864 147,699 - 213,124 29,776 - 29,776 53,306 296,206 1993-94 20,411 53,981 55,896 - 130,288 23,800 - 23,800 109,581 263,669 1994-95 21,837 33,300 100,578 - 155,715 22,109 1,480 23,589 50,898 230,202 1995-96 18,012 53,862 62,920 - 134,794 21,293 4,170 25,463 51,333 211,590 1996-97 22,738 49,959 58,262 - 130,959 21,112 6,241 27,353 39,394 197,706 1997-98 952 37,017 96,706 - 134,675 15,621 8,306 23,927 30,330 188,932 1998-99 - 47,201 32,013 - 79,214 18,619 6,973 25,591 23,516 128,321 1999-00 45,037 43,270 20,607 - 108,914 21,210 7,460 28,670 22,278 159,862 2000-01 23,451 46,343 39,725 - 109,519 21,621 6,838 28,459 21,181 159,159 2001-02 41,268 60,596 18,607 - 120,471 22,144 7,276 29,420 20,720 170,611 2002-03 17,297 42,796 63,271 - 123,364 21,920 6,192 28,112 11,205 162,681 2003-04 27,520 44,925 30,467 - 102,912 19,269 3,669 22,938 - 125,850 2004-05 25,296 29,503 148,674 - 203,473 15,975 3,920 19,895 7,804 231,172 2005-06 33,229 42,022 60,377 - 135,628 14,298 6,620 20,918 9,889 166,435 2006-07 40,214 45,039 11,495 - 96,748 11,451 12,912 24,363 9,264 130,375 2007-08 1,510 39,767 54,518 - 95,795 11,597 14,690 26,287 - 122,082 2008-09 - 39,611 35,348 - 74,959 15,873 10,123 25,996 - 100,955 2009-10 26,286 55,731 35,398 - 117,415 17,752 11,432 29,184 - 146,599 2010-11 37,315 37,131 113,295 - 187,741 13,363 11,285 24,648 6,724 219,113 2011-12 - 55,797 36,155 - 91,952 10,082 8,312 18,394 7,815 118,161 2012-13 - 59,145 6,048 - 65,193 14,707 11,240 25,947 2,180 93,320 2013-14 - 55,646 -- 55,646 13,677 17,587 31,263 4,371 91,280 2014-15 18,515 44,349 15,892 - 78,757 10,013 17,345 27,358 12,723 118,838 2015-16 23,961 57,811 14,183 - 95,956 8,105 17,152 25,257 - 121,213 2016-17 32,693 58,067 70,027 - 160,786 11,092 15,587 26,679 - 187,465 TOTAL 2,535,869 2,030,995 2,950,480 215,121 7,732,466 1,507,501 216,810 1,724,309 873,319 10,330,094 Average 47,847 36,268 51,763 14,341 133,318 25,991 9,427 29,729 18,985 178,105 * Does not include Alamitos Barrier water purchased by the Orange County Water District for the Orange County Basin
38 ibid
Progress Memorandum to Carolina Hernandez 4 December 2018 Page 38
The WRD Board of Directors also determined, after extensive review and analysis of water level fluctuations in the district, that the optimum quantity of Accumulated Overdraft (AOD) is 612,000 AF and the minimum quantity of AOD is 900,000 AF. They also adopted a policy related to managing the basin when the Optimum AOD falls too low: “An Accumulated Overdraft greater than the Optimum Quantity is a deficit. WRD will make up the deficit within a 20-year period as decided by the Board on an annual basis. If the deficit is within 5 percent of the Optimum Quantity, then no action needs to be taken to allow for natural replenishment to makeup the deficit.”39 Figure 27 illustrates how WRD, in partnership with LACDPW, LACFCD, SDLAC, LASAN, and WBMWD, has been highly successful at managing and keeping the basin in balance, within the Optimal AOD.
Figure 27: Accumulated overdraft in the WRD groundwater basins
Historical replenishment averages 178,000 AFY, consisting of approximately 60% of recycled, local, makeup and in-lieu water, and 40% of imported water. Historical total water use in the WRD service area averages to about 620,000 AFY, with approximately 250,000 AFY in groundwater production, 350,000 AFY in imported water use, and 20,000 AFY in reclaimed water use.40 Figure 28 shows how
39 ibid. 40 ibid.
Progress Memorandum to Carolina Hernandez 4 December 2018 Page 39
through WRD’s aggressive conservation efforts and effective management of the basin, demand for imported water has been reduced. For the past 30 years, direct water use overlying the basin has been steadily declining. During this same time period, imported water use overlying the basin has decreased by over 200,000 AFY while recycled water use has steadily increased to approximately 35,000 AFY.
Figure 28: Direct water use in the WRD service area
In 2016-17, total overlying demand in the WRD service area was 487,000 AF, of which 298,000 AF was demand in the Central Basin and 189,000 AF was demand in the West Coast Basin. In the Central Basin, 183,000 AF was supplied through water rights extractions, 101,000 AF was supplied through imported water, and 14,000 AF was supplied through recycled water. In the WCB, 27,000 AF was supplied through water rights extractions, 139,000 AF was supplied through imported water, and 23,000 AF was supplied through recycled water (Figure 29).
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Figure 29: Total overlying demand in the Central and West Coast Basins in 2016-17
Recent Judgement Amendments allow for water rights holders enhanced use of unused storage space in the CB and WCB and for increased pumping above the adjudicated rights by recharging the basin with new water supplies through water augmentation projects. The Amendments include rules for the use of the unused storage space, which is divided into basin operating reserve, individual storage accounts, community storage pool, regional storage projects, and water rights transfers. Pumpers are permitted to convert carryover to storage for later recovery and for use of 330,000 AF of storage space in the Central Basin and 120,000 AF of storage space in the West Coast Basin. The ability to use storage provides pumpers the ability to bank water for future uncertainty. Storage and augmentation can be used to allow pumpers to meet greater demand from the basin and reduce overlying use of imported water. The Los Angeles River is a potential supply source for augmentation and increased groundwater production, providing valuable benefits for the region.
Groundwater recharge pathways vary. The SFB overlies an unconfined aquifer, which makes it suitable for surface spreading while the CB and WCB overlie confined aquifers. The 2015 SCMP41 created an inventory and synthesized existing and planned actions by LADWP, LACFCD, other City, County, regional, and Federal agencies, and local non-governmental entities that impact stormwater.
41 LADWP, August 2015, Stormwater Capture Master Plan.
Progress Memorandum to Carolina Hernandez 4 December 2018 Page 41
Extensive hydrologic modeling calculated the amount of stormwater generated and the multiple constraints associated with capturing the stormwater for beneficial use and determining the realistic amount of stormwater that can be relied upon currently and under future scenarios. Some of the identified projects are located at County-owned or jointly managed facilities, which include Big Tujunga and Pacoima Dam to LA Filtration Plant, Big Tujunga Dam Sediment Removal, Canterbury Power Line Easement, LA Forebay Recharge System (LAR Pilot, LAR Full Scale, and Upper Ballona), Old Pacoima Wash, San Fernando Road Swales, Spreading Grounds Optimization, Valley Generating Station Stormwater Capture (Phase I and II), and Van Norman Stormwater Capture, among many others.
Development of local water supply represents a resource value that accrues over time. The value can be monetized by avoiding expenses of purchased water. In addition, due to the uncertain nature in the availability of purchased imported water, there is a regional value to increasing the volume of local groundwater storage and developing local supplies and that are in excess of the value of the purchased water itself.
Conclusions
1. Flood Management Capacity • The flood management capacity of the Los Angeles River has been vastly improved through channelization efforts during the 1930s through 1950s, and subsequent improvements in the Lower River in the late 1990s through early 2000s. Despite these efforts flood-risk remains a real threat, particularly in the Glendale Narrows reach. Finding solutions for these deficient conditions remains a priority.
• The history of the LA River channelization indicates that improvements typically followed large and often catastrophic flood events. Even the recent improvements in the lower river were motivated by a large event in 1980 that resulted in re-analysis of flood frequency incorporating additional decades of hydrology data. Today, it is almost three decades since the hydrology was studied, and the current levels of protection were estimated. Given the large amount of additional data, improved analysis techniques, and the acknowledgement of climate change and non-stationarity, it is imperative that the hydrology be revised to better estimate and proactively manage flood risk.
• It is acknowledged that while flood risk can be managed to a certain level, there is always the possibility of the “big one” resulting in inundation of cities and neighborhoods. Planning should involve assessment of locations of critical infrastructure and hazardous facilities, to plan evacuation routes and other mitigation strategies. Updated hydrologic analyses and more detailed flood plain mapping including estimates of flow velocities and depths may form an important part of this analyses.
2. Water Quality • The Los Angeles River is an impaired water body with five TMDLs established for 13 pollutants. Three EWMP/WMPs have been developed within the Los Angeles River
Progress Memorandum to Carolina Hernandez 4 December 2018 Page 42
Watershed and served as the guidance for TMDL compliances. Additional water quality improvements are needed to meet water quality targets established in EWMP/WMPs.
• Uncertain funding and implementation scenarios exist making the timeline to water quality compliance difficult to predict. Creative funding measures and alternative project delivery scenarios, such as public-private-partnerships, may be required to keep pace with regulations.
3. Water Supply • Approximately 50,000 AF of dry weather flow travels down the Los Angeles River to the ocean every year. The average annual volume of wet weather flow that reaches the ocean is approximately 280,000 AF (ranging from less than 50,000 AF to nearly 1,000,000 AF).
• The LA River’s base flow and stormwater flow are valuable resources that can be used to develop the region’s local water supply portfolio to reduce the region’s dependence on imported water and improve system reliability and resilience.
• Efforts to capture flows in the Upper and Lower LA River Watershed for groundwater recharge in the SFB and CB should continue to be prioritized.
END OF MEMORANDUM LARMP_Task 10_Progress Memo for Tasks 3-1_3-2_Water Resources-Flood_WaterQuality_WaterSupply
PROGRESS
LOS ANGELES RIVER MASTERPLAN UPDATE
LARMP TASK 3.1 & 3.2 WATER RESOURCES: FLOOD, WATER QUALITY, WATER SUPPLY
03 December 2018
1 PROGRESS FLOOD RISK MANAGEMENT
LA RIVER FLOOD CHANNEL, 1978 Source: Clarence Inman Collection, Floodwaters rushing along the Narrows southward under the Los Feliz Bridge in 1978. Accessed from: https://boomcalifornia.com/2013/06/17/showdown-at-the-glendale-narrows/
2 WATER RESOURCES PROGRESS
LA RIVER FLOOD CHANNEL, 5 JANUARY 2016 Source: Flickr user Scott L, 1_E1C7494, 2016
3 WATER RESOURCES PROGRESS THE LA RIVER AND ITS 9 MAJOR TRIBUTARIES, DRAIN AN 834 SQ. MI. WATERSHED
Source: Geosyntec, Los Angeles County GIS Data Portal
4 WATER RESOURCES PROGRESS SLOPES IN THE UPPER WATERSHED ARE PREDOMINANTLY ORIENTED TO THE SOUTH
Slope Aspect
North
West Flat East
South
Source: U.S. Geological Survey, 2013, USGS NED 1 arc-second 2013
5 + Mount Pacifico 7,103 ft WATER RESOURCES San Gabriel Mountains +Oat Mountain PROGRESS 3,747 ft THE LA RIVER San Fernando Valley +Verdugo Peak DROPS 780 FEET 3,126 ft IN JUST 51 MILES +San Vicente Peak 1,985 ft Santa Monica Mountains High (7,103 ft)
Los Angeles Plain Low (0 ft)
780772 ft ft
00 ft ft 51 FOOTHILLSFOOTHILLS 25NARROWSCANYONS 17ALLUVIALALLUVIAL PLAIN PLAIN4MOUTH MOUTH 0
Source: U.S. Geological Survey, 2013, USGS NED 1 arc-second 2013
6 WATER RESOURCES PROGRESS HISTORICAL WETLAND ECOLOGY (1870)
Historical Wetlands Current Wetlands Historical and Current Wetlands Historical Floodplain
Source: Adapted from: Charles Rairdan, 1998. Regional restoration goals for wetland resources in the Greater Los Angeles Drainage Area: A landscape-level comparison of recent historic and current conditions using Geographical Information Systems. Dissertation. UCLA
7 WATER RESOURCES PROGRESS HISTORICAL FLOODING AND RIVER PATHS
PRIOR TO 1825 Mapping of Extent
Areas Subject to Inundation Historic River PathsCourses
Source: Based on Blake Gumprecht, “The Los Angeles River: Its Life, Death, and Possible Rebirth.”, 2001
8 WATER RESOURCES PROGRESS
Yearly annual average rainfall (Downtown City of Los Angeles) HISTORICAL FLASH RAIN Major storm and flooding events AND FLOOD EVENTS x Major droughts
40”
30”
20”
14.4” x x x x x AVG 10”
0” 1862 1884 1921 1939 1969 1983 2010 Noachian Deluge of Heavy winter Heavy Storm: Tropical Storm: Heavy Rains: El Nino: El Nino fuels California: storms: • 6.76” in LA • 5.42” in LA • 13.4” in 10 days • Up to 18” in 3 days winter storms: • downed trees • 30 consecutive days • mudslides in LA 1934 • 87 deaths in 1980 of rain wash away newly California and powerlines Major Storm: 6 Storms: • 35” in LA City laid railroad tracks 1938 •mud and debris • 7.36” in LA in 24 hours • 12.75” in 9 days • LA River mouth Los Angeles Basin Flood: flows prompted • 45 deaths regionally • 30 deaths regionally shifts from Venice to • 10” rain evacuation Wilmington • 115 deaths • 5,601 homes lost • $70 million damage
Source: Western Regional Climate Center, Cooperative Climatological Data Summaries, 2018 & County of Los Angeles Chief Executive Office’s Office of Emergency Management, History of Floods, Mudslides, Debris Flows, Landslides in Los Angeles County Operational Area, 2012, https://ceo.lacounty.gov/wp-content/uploads/OEM/HazardsandThreats/Landslides/HAZARDS%20AND%20THREAT%20FLOODS%20-%20MUDSLIDES%20-%20LANDSLIDES%20HISTORY.pdf 9 WATER RESOURCES PROGRESS LA RIVER HISTORY: NORTH FIGUEROA BRIDGE AT ARROYO SECO 1938
Source: Los Angeles Public Library, 1938 from Boyle Heights
10 WATER RESOURCES PROGRESS LA RIVER HISTORY: GRIFFITH PARK 1938
Source: Army Corps of Engineers, 1938, Griffith Park
11 WATER RESOURCES PROGRESS LA RIVER HISTORY: 1948-1951
Source: Los Angeles Public Library
12 WATER RESOURCES PROGRESS HYDRAULICS
Source: Olin
13 WATER RESOURCES PROGRESS HYDRAULICS
Analysis of the River channel geometry: Mannings (weighted) for main channel: vegetation (roughness), width, depth, and slope.
Channel geometry data were extracted from the US Army Corps one-dimensional HEC- RAS (Hydraulic Engineering Center - River Top width of channel (ft.) Analysis System) version 4.1 model for the Los Angeles River. These data were used to define hydraulically similar Design Reaches, A through M, as indicated in the figure and on the map on Slide 13. Maximum channel depth (ft.)
Minimum Channel Elevation (ft.)
Source: Geosyntec
14 WATER RESOURCES PROGRESS HYDRAULIC DESIGN REACHES
Classification M, Mile 47.4 to 51.0 F, Mile 24.5 to 30.3 L, Mile 45.6 to 47.2 E, Mile 19.8 to 23.9 K, Mile 43.4 to 45.4 D, Mile 18.9 to 19.7 J, Mile 37.8 to 42.7 C, Mile 12.8 to 18.8 I, Mile 33.9 to 37.5 B, Mile 3.0 to 11.9 H, Mile 32.0 to 33.8 A, Mile 0.0 to 2.8 G, Mile 31.1 to 31.8 Transition
Source: Geosyntec
15 WATER RESOURCES PROGRESS CHANNEL SHAPE VARIES
Classification Trapezoidal Rectangular
Source: Geosyntec
16 WATER RESOURCES PROGRESS CHANNEL MATERIAL VARIES
Classification: Soft Bottom (Earthen) Concrete
Source: Geosyntec
17 WATER RESOURCES PROGRESS CHANNEL WIDTH VARIES
Classification: Narrow, 55 ft
Wide, 585 ft
Source: Geosyntec
18 WATER RESOURCES PROGRESS RIVER CHANNELIZATION: CROSS SECTIONS
REACH 7 0 20 Feet
Confluence - Mile 51
REACH 5 0 20 Feet
Valley - Mile 46
REACH 4 0REACH20 Feet 4 0 20 Feet
Soft Bottom - Mile 34.5
REACH 3 0 20 Feet
Downtown - Mile 22
Source: OLIN REACH 2 0 20 Feet
Southeastern Cities - Mile 17 19 WATER RESOURCES PROGRESS LA RIVER AVERAGE FLOW: 90-95% OF THE TIME
Source: Olin
20 WATER RESOURCES PROGRESS LA RIVER AT SPRING STREET BRIDGE: 5-10% OF THE TIME
Source: Geosyntec
21 WATER RESOURCES PROGRESS LA RIVER AT LOS FELIZ BRIDGE, 1969 <1% OF THE TIME
Source: LA Times
22 WATER RESOURCES PROGRESS HYDRAULICS MODELING RESULTS FROM USACE 1-D HEC-RAS MODELS1,2,3 AT DESIGN DISCHARGE/CAPACITY3
Design Discharge / Capacity3 Flow Flow Froude (cubic feet per second) Depth (ft) Velocity (fps) Number4
200K 100K 0 100K 200K Canoga Park 51 51 50 49 48 Reseda 47 47 46 45 Van Nuys 44 Sepulveda Sepulveda Sepulveda Sepulveda 44 Basin Basin Basin Basin 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 Tujunga Wash 37 36 35 34 Burbank 33 33 32 Glendale 31 31 Verdugo Wash 30 29 28 27 26 25 Arroyo Seco 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 12 South Gate 12 Rio Hondo 11 10 Compton 9 9 8 7 6 Compton Creek 7.2 5.2 0.21 - 0.86 (subcritical, stable) 5 0.86 - 1.13 (unstable) 4 3 1.13 - 2.0 (supercritical, stable) 2 1 Long Beach 0 33.2 44.1 2.0 - 2.38 (supercritical, unstable) 0
Footnotes: 1. U.S. Army Corps of Engineers: Los Angeles District. Los Angeles County Drainage Area, Stormwater Management Plan, Phase I, HEC-RAS Hydraulic Models, Rio Hondo Channel and Lower Los Angeles River. 2. U.S. Army Corps of Engineers: Los Angeles District. Los Angeles County Drainage Area, Upper Los Angeles River and Tujunga Wash HEC-RAS Hydraulic Models. 3. HEC-RAS models were updated by Geosyntec to include new 6th Street Bridge (currently under construction) at River Mile 21.1. 4. The flow rates in the 1-D HEC-RAS models provided by USACE for the LA River are a combination of design discharge and channel capacities and represent at or near capacity conditions. 5. The Froude number is the dimensionless ratio of channel velocity to wave speed for open channel flow. When Froude < 1 the flow is subcritical (slower and deeper) and when Froude > 1 the flow is supercritical (faster and shallower). Between Froude numbers of approximately 0.86 and 1.13 the flow can easily change between subcritical and supercritical states and tends to become unstable with formation of surface waves. Froude numbers greater than approximately 2 are also unstable. 23 WATER RESOURCES PROGRESS FREQUENCY DISCHARGES
2 Design Discharge / Capacity 50 Year 100 Year 133 Year 200 Year 500 Year Composite (cfs) Frequency Frequency Frequency Frequency Frequency 2,3 4 4 4 4 4 Frequency (USACE 1-D HEC-RAS models ) Discharge (cfs) Discharge (cfs) Discharge (cfs) Discharge (cfs) Discharge (cfs) Discharge (cfs)
200K 100K 0 100K 200K 200K 100K 0 100K 200K 200K 100K 0 100K 200K 200K 100K 0 100K 200K 200K 100K 0 100K 200K 200K 100K 0 100K 200K 200K 100K 0 100K 200K Canoga Park 51 51 50 49 48 Reseda 47 47 46 45 Van Nuys 44 Sepulveda Sepulveda Sepulveda Sepulveda Sepulveda Sepulveda Sepulveda 44 Basin Basin Basin Basin Basin Basin Basin 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 1 Long Beach 0 0
Footnotes: 1. Flow rates are from the 1-D HEC-RAS models provided by USACE for the LA River and are a combination of design discharge and channel capacities and represent at or near capacity conditions. 2. U.S. Army Corps of Engineers: Los Angeles District, 2004. Los Angeles County Drainage Area, Stormwater Management Plan, Phase I, HEC-RAS Hydraulic Models, Rio Hondo Channel and Lower Los Angeles River. 3. HEC-RAS models were updated by Geosyntec to include new 6th Street Bridge (currently under construction) at River Mile 21.1. 4. U.S. Army Corps of Engineers: Los Angeles District, 2005. Los Angeles County Drainage Area, Upper Los Angeles River and Tujunga Wash HEC-RAS Hydraulic Models 5. U.S. Army Corps of Engineers: Los Angeles District. 1991. Los Angeles County Drainage Area: Review, Part II Hydrology Report, Project Alternatives. Table 1: Discharge-Frequency Results, Recommended Project Conditions. 24 WATER RESOURCES PROGRESS EFFECT OF URBANIZATION
Source: U.S. Army Corps of Engineers: Los Angeles District. 1991. Los Angeles County Drainage Area: Review, Part I, Hydrology Technical Report, Base Conditions
25 WATER RESOURCES PROGRESS FEMA FLOODPLAIN MAPPING i. Steady-state 1-D modeling of Los Angeles River with specific break out areas analyzed to determine flood plain.
100 Year Flood Plain (9.7 sq mi / 1.2% Basin) 500 Year Flood Plain (39.8 sq mi / 4.8% Basin)
Source: Los Angeles County GIS Data Portal, Flood Zones; The Flood Insurance Study (FIS) for Los Angeles County was issued by FEMA in 2008 and revised in 2016
26 WATER RESOURCES PROGRESS USACE FLOODPLAIN MAPPING i. Unsteady 1-D modeling of Los Angeles River with full 2-D flood plain modeling. ii. Analyses limited to 13 miles between Barham Boulevard and First Street.
100 Year Flood Plain 500 Year Flood Plain
Source: USACE, Floodplain Management Services Special Study Los Angeles River Floodplain Analysis, October 2016; Mapping limited to area from Barham Boulevard to First Street)
27 WATER RESOURCES PROGRESS FLOOD RISK
View from Glendale Blvd Bridge | Approx. 12,000 Cubic Feet/Second Source: Gehry Partners Employee, 01/22/2017 Over 3,300 PARCELS across Los Angeles County will be submerged by an average of 5 to 10 feet of water when a 100 year flood event occurs. Source: ArmyUSACE, Corps 2016 of Engineers (2016)
28 WATER RESOURCES PROGRESS VEGETATION AND WATER CONVEYANCE Vegetation and Flood Control Capacity Have an Inverse Relationship
40%-50% CAPACITY PLANTED BANKS + CONCRETE CHANNEL
55% CAPACITY GRASSED BANKS + GRASSED CHANNEL
75% CAPACITY GRASSED BANKS + CONCRETE CHANNEL
80% CAPACITY LOW FLOW CHANNEL PLANTED WITH SHRUBS/TREES + CONCRETE CHANNEL
95% CAPACITY LOW FLOW CHANNEL PLANTED WITH GRASSES + CONCRETE CHANNEL Source: Geosyntec & OLIN, Tested Channel Capacity Scenarios At River Mile 11.8 (Rio Hondo Confluence).
29 WATER RESOURCES PROGRESS ARkSTORM SCENARIO i. The ARkStorm is a hypothetical storm scenario based upon back-to-back atmospheric river (AR) events, using historic storm events from January 1969 and February 1986, simulated on a state-wide scale. ii. The scenario may represent an event as rare as 1 in 1000 years for parts of California, although the resulting rainfall in the Los Angeles region was determined to be similar to a 1 in 500 year event. iii. Detailed hydraulic modeling was not performed, but rather the resulting floodplains were based upon the FEMA 500-year floodplain. iv. The results are for illustrative purposes only, and should not be used to quantitatively assess flood risk. v. For more information see: https://pubs.usgs.gov/of/2010/1312/
ARkStorm Scenario (USGS) ”Anthropogenic forcing is found to yield large twenty-first-century increases in the frequency of wet extremes, including a more than threefold increase in sub-seasonal events comparable to California’s ‘Great Flood of 1862’.”
Swain, Daniel L., Baird Langenbrunner, J. David Neelin, and Alex Hall, “Increasing precipitation volatility in twenty-first-century California”, Nautre, 2018
Source: USGS, Summary map showing ARkStorm predictions for California, 2017, https://www.usgs.gov/media/images/summary-map-showing-arkstorm-predictions-california
30 WATER RESOURCES PROGRESS TSUNAMI INUNDATION AREA
Tsunami Inundation Area (20 sq mi / 0.4% LA County)
Source: State of California, 2009, Tsunami Inundation Map for Emergency Planning, produced by California Emergency Management Agency, California Geological Survey, and University of Southern California – Tsunami Research Center
31 WATER RESOURCES PROGRESS 1.41 METER SEA LEVEL RISE WITH 100 YEAR COASTAL STORM EVENT i. The high-end SLR scenario (1.41 meter SLR) used in this study conforms with California’s Climate Change Assessments to date, which are estimated for California under the A1B and A2 emission scenarios (Bromirski et al. 2012). ii. There is uncertainty regarding the upper-bound or high-end for SLR by the end of the century and other studies have predicted higher estimates (NRC, 2012) of as much as 1.67 meters (CO-CAT 2013, p.2)
1.41 meter Sea Level Rise with 100 Year Coastal Storm Event (11 sq mi / 0.2% LA County)
Source: Cal-Adapt, Seal Level Rise Tool, 1.41 meters Sea Level Rise Scenario, 2018, Downloaded from:http://keystone.gisc.berkeley.edu/cec_gas_study_layers/South_coast/
32 WATER RESOURCES PROGRESS FLOOD HAZARDS
100 Year Flood Plain (FEMA & USACE) 500 Year Flood Plain (FEMA & USACE) Tsunami Inundation Area (CalOES) 1.41 meter Sea Level Rise with 100 Year Storm Event (Cal-adapt)
Source: Los Angeles County GIS Data Portal, Flood Zones; The Flood Insurance Study (FIS) for Los Angeles County was issued by FEMA in 2008 and revised in 2016 & USACE, Floodplain Management Services Special Study Los Angeles River Floodplain Analysis, October 2016; Mapping limited to area from Barham Boulevard to First Street), & tate of California, 2009, Tsunami Inundation Map for Emergency Planning, produced by California Emergency Management Agency, California Geological Survey, and University of Southern California – Tsunami Research Center Cal-Adapt, Seal Level Rise Tool, 1.41 meters Sea Level Rise Scenario, 2018, http://keystone.gisc.berkeley.edu/cec_gas_study_layers/South_coast/
33 WATER RESOURCES PROGRESS MITIGATION SAVES MONEY
National Benefit-Cost Ratio Per Peril Federally Beyond Code *BCR numbers in this study have been rounded Funded Requirements Overall Hazard Benefit-Cost Ratio 6:1 4:1 Riverine Flood1 7:1 5:1
Source: Multihazard Mitigation Council (2017) Natural Hazard Mitigation Saves 2017 Interim Report: An Independent Study. Footnotes: 1. Benefit-cost ratio for riverine flooding based on modeling of the 1% annual chance flood 34 WATER RESOURCES PROGRESS CRITICAL FACILITIES CriticalA structure Facilities or other types improvement based on: Losthat, Angeles because County of its function, Comprehensive size, service area, Floodplainor uniqueness, Management has the potential Plan, September to cause 2016serious bodily harm, extensive property damage, or disruption of vital socioeconomic activities if it is destroyed or damaged or if its functionality is impaired.
Critical facility types based on: Los Angeles County Comprehensive Floodplain Management Plan, September 2016
Disaster and Emergency Operations Center Police and Fire Stations Medical Facilitates Schools Hazardous Facilities
Source: Los Angeles County GIS Data Portal, Points of Interest, 2016 & EPA, FRS Geospatial Data, 2018
35 WATER RESOURCES PROGRESS CRITICAL INFRASTRUCTURE A structure or other improvement that, because of its function, size, service area, or uniqueness, has the potential to cause serious bodily harm, extensive property damage, or disruption of vital socioeconomic activities if it is destroyed or damaged or if its functionality is impaired.
Critical infrastructure types based on: Los Angeles County Comprehensive Floodplain Management Plan, September 2016
Evacuation Routes Transition Lines Passenger Rail Wastewater Treatment Plants Electric Power Facility Oil and Gas Facilities Public Transit Facilities Bridges Freeway Exits
Source: Los Angeles County GIS Data Portal, Points of Interest, 2016 & Los Angeles County GIS Data Portal, Disaster Routes, 1998 & California Department of Transportation, California Rail Network, 2013 & EPA, FRS Geospatial Data, 2018 & State of California Energy Commission, California Electric Transmission Line, 2018 & California Department of Conservation, All Wells, 2018
36 WATER RESOURCES PROGRESS FLOOD HAZARDS & CRITICAL FACILITIES & INFRASTRUCTURE Disaster and Emergency Operations Centers Police and Fire Stations Medical Facilities Schools Hazardous Facilities 100 Year Floodplain (FEMA & USACE) 500 Year Floodplain (FEMA & USACE) Tsunami Inundation Area (CalOES) 1.41 meter Sea Level Rise with 100 Year Storm Event (Cal-adapt) Evacuation Routes Transmission Lines Passenger Rail Wastewater Treatment Plants Transit Facilities Oil and Gas Facilities Bridges Electric Power Facilities Freeway Exits
Source: Los Angeles County GIS Data Portal, Points of Interest, 2016 & Los Angeles County GIS Data Portal, Disaster Routes, 1998 & California Department of Transportation, California Rail Network, 2013 & EPA, FRS Geospatial Data, 2018 & State of California Energy Commission, California Electric Transmission Line, 2018 & California Department of Conservation, All Wells, 2018 & Los Angeles County GIS Data Portal, Flood Zones; The Flood Insurance Study (FIS) for Los Angeles County was issued by FEMA in 2008 and revised in 2016 & USACE, Floodplain Management Services Special Study Los Angeles River Floodplain Analysis, October 2016; Mapping limited to area from Barham Boulevard to First Street), & State of California, 2009, Tsunami Inundation Map for Emergency Planning, produced by California Emergency Management Agency, California Geological Survey, and University of Southern California – Tsunami Research Center Cal-Adapt, Seal Level Rise Tool, 1.41 meters Sea Level Rise Scenario, 2018, http://keystone.gisc.berkeley.edu/cec_gas_study_layers/South_coast/ 37 WATER RESOURCES PROGRESS FLOOD HAZARDS & CRITICAL FACILITIES & INFRASTRUCTURE
WITHIN FLOOD HAZARD AREA TOTAL FACILITY DESCRIPTION FEMA 100-YR FEMA 500-YR TSUNAMI 1.41M SEA LEVEL ANY OF THE 4 FACILITIES FLOODPLAIN FLOODPLAIN INUNDATION RISE W/ 100-YR FLOOD HAZARD STORM EVENT AREAS EMERGENCY OPERATIONS FACILITIES 2 12 1 1 12 105 POLICE STATIONS 1 14 1 0 15 119
FIRE STATIONS 10 72 18 10 79 451
MEDICAL CARE FACILITIES 37 752 16 12 757 5,754
SCHOOLS 43 673 6 5 673 4,745
HAZARDOUS MATERIAL SITES 311 2,836 243 210 2,910 18,667
TOTALS 404 4,359 285 238 4,446 29,841
Note: Not all infrastructure and facilities in the flood hazard area are directly caused by flooding from the LA River.
Calculated from: Los Angeles County GIS Data Portal, Points of Interest, 2016 & Los Angeles County GIS Data Portal, Disaster Routes, 1998 & California Department of Transportation, California Rail Network, 2013 & EPA, FRS Geospatial Data, 2018 & State of California Energy Commission, California Electric Transmission Line, 2018 & Los Angeles County GIS Data Portal, Flood Zones; The Flood Insurance Study (FIS) for Los Angeles County was issued by FEMA in 2008 and revised in 2016 & USACE, Floodplain Management Services Special Study Los Angeles River Floodplain Analysis, October 2016; Mapping limited to area from Barham Boulevard to First Street), & tate of California, 2009, Tsunami Inundation Map for Emergency Planning, produced by California Emergency Management Agency, California Geological Survey, and University of Southern California – Tsunami Research Center Cal-Adapt, Seal Level Rise Tool, 1.41 meters Sea Level Rise Scenario, 2018, http://keystone.gisc.berkeley.edu/cec_gas_study_layers/South_coast/ 38 WATER RESOURCES PROGRESS CONDITIONS ALONG THE LA RIVER CORRIDOR
FEMA 100 and 500 Year Hydraulic Composite: Composite: Design Width at Channel Channel LA River Flood Hazard Tsunami & Critical Critical Reaches Tributaries Top of Channel Shape Material Area Composite Sea Level Rise Facilities Infrastructure
Canoga Park 51 51 50 M 125 ft 49 Aliso 48 Reseda 47 Canyon 47 L Wash 200 ft 46 45 Van Nuys 44 K Sepulveda 44 Basin 43 42 Sherman Oaks 41 41 J 55 ft 40 39 38 Tujunga Studio City 37 37 I Wash 36 125 ft 35 34 Burbank H 33 Burbank 33 Western 130 ft 32 Channel Glendale 31 G 240 ft 31 Verdugo 30 Wash 29 28 F 305 ft 27 26 25 Arroyo 24 Seco 23 Downtown LA 22 22 E 225 ft 21 20 D 285 ft 19 Vernon 18 18 17 C 415 ft 16 15 Bell Gardens 14 14 13 South Gate 12 Rio 12 Hondo 11 10 Compton 9 9 8 B 400 ft 7 Compton 6 Creek 5 4 3 2 A 585 ft 1 Long Beach 0 0
39 WATER RESOURCES PROGRESS HAZARDOUS FACILITIES: WITHIN 1 MILE OF LA RIVER
Large Quantity Hazardous Wastewater Composite: Waste Brownfield Treatment Toxic Release Superfund Polluting Hazardous Generators Sites Plants Sites Sites Power Plants Facilities
Canoga Park 51 51 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 1 Long Beach 0 0
40 WATER RESOURCES PROGRESS CRITICAL FACILITIES: WITHIN 1 MILE OF LA RIVER
Disaster and Composite: Composite: Emergency Composite: Hazardous Composite: Medical Police and Fire Operations Critical Facilities Schools Facilities Stations Centers Facilities
Canoga Park 51 51 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 1 Long Beach 0 0
41 WATER RESOURCES PROGRESS CRITICAL INFRASTRUCTURE: WITHIN 1 MILE OF LA RIVER
Composite: Wastewater Oil and Gas Electric Power Transmission Transit Critical Facilities Facilities Facilities Lines Metro/Railways Freeways Freeway Exits Bridges Facilities Infrastructure
Canoga Park 51 51 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 1 Long Beach 0 0
42 PROGRESS WATER QUALITY
Source: Olin
43 WATER RESOURCES PROGRESS WATER AS RECREATIONAL RESOURCE
Source: Flickr User Los Angeles District, LA River, 2013
44 WATER RESOURCES PROGRESS WATER QUALITY IMPROVEMENTS, DOMINGUEZ GAP WETLANDS, 2018
Source: Olin
45 WATER RESOURCES PROGRESS WATER QUALITY PRIORITIES
Priority Areas 1 (Lower) 5 (Higher)
Source: LACDPW LSPC Model Input, 2012, http://dpw.lacounty.gov/wmd/irwmp/; Geosyntec, 2018
46 WATER RESOURCES PROGRESS TRIBUTARY AREAS
Direct Tributary Area < 1mi2 at the head 207 mi2 at the mouth
Total Tributary Area 40 mi2 at the head 834 mi2 at the mouth
Cumulative Direct Drainage Area to the LA River River Mile 51 River Mile 0 Cumulative Total Drainage Area to the LA River River Mile 51 River Mile 0
Source: LACDPW LSPC Model Input, 2012
47 WATER RESOURCES PROGRESS TRIBUTARY AREAS
Total/Direct Total/Direct LAR Watershed LAR Watershed Drainage Area Drainage Area (River Right/Left)
Canoga Park 51 51 2 2 2 50 40/<1 mi 15/<1 mi 25/<1 mi 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 Tujunga Wash Tujunga Wash 37 2 2 +224 mi +224 mi 36 35 34 Burbank 33 33 32 Glendale 31 31 Verdugo Wash Verdugo Wash 30 2 2 +25 mi +25 mi 29 28 27 26 25 Arroyo Seco Arroyo Seco 24 +47 mi2 +47 mi2 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 12 South Gate 12 Rio Hondo Rio Hondo 2 2 11 +142 mi +142 mi 10 Compton 9 9 8 7 6 Compton Creek Compton Creek 5 2 2 +42 mi +42 mi 4 3 2 834/207 mi2 134/71 mi2 698/135 mi2 1 Long Beach 0 0
48 WATER RESOURCES PROGRESS PRIORITIESPROJECTS WITH WITH WATER WATER QUALITY BENEFITS QUALITY BENEFITS
Water Quality Projects Constructed In-Development Planned Cumulative Direct Drainage Area to the LA River River Mile 51 River Mile 0
Source: OLIN/Geosyntec, LARMP Task 2 Project Database
49 WATER RESOURCES PROGRESS EWMP/WMP TARGET RULER
EWMP/WMP EWMP/WMP EWMP/WMP Storage Requirements Planned Projects Storage Shortfall (Acre-Feet) (Acre-Feet) (Acre-Feet) 300 200 100 0 100 200 300 300 200 100 0 100 200 300 300 200 100 0 100 200 300 Canoga Park 51 51 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 1 Long Beach 0 0
Source: ULAR EWMP (2016), https://www.waterboards.ca.gov/losangeles/water_issues/programs/stormwater/municipal/watershed_management/los_angeles/upper_losangeles/20160127/UpperLARiver_mainbody_revEWMP_Jan2016.pdf, LAR UR2 WMP (2015), https://www.waterboards. ca.gov/losangeles/water_issues/programs/stormwater/municipal/watershed_management/los_angeles/upper_reach2/Upper_LA_River_R2_FinalWMP.pdf, LLAR WMP (2017), https://www.waterboards.ca.gov/losangeles/water_issues/programs/stormwater/municipal/watershed_ management/los_angeles/lower_losangeles/LLARWMP2017updated.pdf 50 WATER RESOURCES PROGRESS MUNICIPAL AND DOMESTIC SUPPLY Uses of water for community, military, or individual water supply systems including, but not limited to, drinking water supply.
MUN Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
51 WATER RESOURCES PROGRESS INDUSTRIAL PROCESS SUPPLY
Uses of water for industrial activities that depend primarily on water quality.
PROC Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
52 WATER RESOURCES PROGRESS INDUSTRIAL SERVICE SUPPLY Uses of water for industrial activities that do not depend primarily on water quality including, but not limited to, mining, cooling water supply, hydraulic conveyance, gravel washing, fire protection, or oil well re-pressurization.
IND Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
53 WATER RESOURCES PROGRESS GROUND WATER RECHARGE Uses of water for natural or artificial recharge of ground water for purposes of future extraction, maintenance of water quality, or halting of saltwater intrusion into freshwater aquifers.
GWR Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
54 WATER RESOURCES PROGRESS NAVIGATION Uses of water for shipping, travel, or other transportation by private, military, or commercial vessels.
NAV Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
55 WATER RESOURCES PROGRESS COMMERCIAL AND SPORT FISHING Uses of water for commercial or recreational collection of fish, shellfish, or other organisms including, but not limited to, uses involving organisms intended for human consumption or bait purposes.
COMM Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
56 WATER RESOURCES PROGRESS WARM FRESHWATER HABITAT Uses of water that support warm water ecosystems including, but not limited to, preservation or enhancement of aquatic habitats, vegetation, fish, or wildlife, including invertebrates.
WARM Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
57 WATER RESOURCES PROGRESS COLD FRESHWATER HABITAT Uses of water that support cold water ecosystems including, but not limited to, preservation or enhancement of aquatic habitats, vegetation, fish, or wildlife, including invertebrates.
COLD Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
58 WATER RESOURCES PROGRESS ESTUARINE HABITAT Uses of water that support estuarine ecosystems including, but not limited to, preservation or enhancement of estuarine habitats, vegetation, fish, shellfish, or wildlife (e.g., estuarine mammals, waterfowl, shorebirds).
EST Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
59 WATER RESOURCES PROGRESS WETLAND HABITAT Uses of water that support wetland ecosystems, including, but not limited to, preservation or enhancement of wetland habitats, vegetation, fish, shellfish, or wildlife, and other unique wetland functions which enhance water quality, such as providing flood and erosion control, stream bank stabilization, and filtration and purification of naturally occurring contaminants.
WET Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
60 WATER RESOURCES PROGRESS MARINE HABITAT Uses of water that support marine ecosystems including, but not limited to, preservation or enhancement of marine habitats, vegetation such as kelp, fish, shellfish, or wildlife (e.g., marine mammals, shorebirds).
MAR Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
61 WATER RESOURCES PROGRESS WILDLIFE HABITAT Uses of water that support terrestrial ecosystems including, but not limited to, preservation and enhancement of terrestrial habitats, vegetation, wildlife (e.g., mammals, birds, reptiles, amphibians, invertebrates), or wildlife water and food sources.
WILD Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
62 WATER RESOURCES PROGRESS RARE, THREATENED, OR ENDANGERED SPECIES Uses of water that support habitats necessary, at least in part, for the survival and successful maintenance of plant or animal species established under state or federal law as rare, threatened, or endangered.
RARE Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
63 WATER RESOURCES PROGRESS MIGRATION OF AQUATIC ORGANISMS
Uses of water that support habitats necessary for migration, acclimatization between fresh and salt water, or other temporary activities by aquatic organisms, such as anadromous fish.
MIGR Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
64 WATER RESOURCES PROGRESS SPAWNING, REPRODUCTION, AND/OR EARLY DEVELOPMENT Uses of water that support high quality aquatic habitats suitable for reproduction and early development of fish.
SPWN Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
65 WATER RESOURCES PROGRESS SHELLFISH HARVESTING Uses of water that support habitats suitable for the collection of filter-feeding shellfish (e.g., clams, oysters, and mussels) for human consumption, commercial, or sports purposes.
SHELL Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
66 WATER RESOURCES PROGRESS WATER CONTACT RECREATION Uses of water for recreational activities involving body contact with water, where ingestion of water is reasonably possible. These uses include, but are not limited to, swimming, wading, water-skiing, skin and scuba diving, surfing, white water activities, fishing, or use of natural hot springs.
REC-1 Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
67 WATER RESOURCES PROGRESS NON-CONTACT WATER RECREATION Uses of water for recreational activities involving proximity to water, but not normally involving body contact with water, where ingestion of water is reasonably possible. These uses include, but are not limited to, picnicking, sunbathing, hiking, beach-combing, camping, boating, tidepool and marine life study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above activities.
REC-2 Classification Existing Stream/Waterbody Potential Stream/Waterbody
Intermittent Stream/Waterbody Not Designated Stream/Waterbody
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
68 WATER RESOURCES PROGRESS NUTRIENT TMDL
Ammonia (mg/L) 1.6 2.4
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
69 WATER RESOURCES PROGRESS NUTRIENT TMDL
Nitrate (mg/L) 8
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
70 WATER RESOURCES PROGRESS NUTRIENT TMDL
Nitrite (mg/L) 1
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
71 WATER RESOURCES PROGRESS NUTRIENT TMDL
Nitrate+Nitrite (mg/L) 8
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
72 WATER RESOURCES PROGRESS TRASH TMDL
Trash (lb) 0
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
73 WATER RESOURCES PROGRESS METALS TMDL — DRY WEATHER
Dry Weather Selenium (μg/L) No Target 5
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
74 WATER RESOURCES PROGRESS METALS TMDL — DRY WEATHER
Dry Weather Copper (μg/L) No Target 22 23 26 30
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
75 WATER RESOURCES PROGRESS METALS TMDL — DRY WEATHER
Dry Weather Lead (μg/L) No Target 10 11 12 19
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
76 WATER RESOURCES PROGRESS BACTERIA TMDL — DRY WEATHER
Dry Weather Bacteria (Exceedance Days Allowed per year) 5 Single Sample E.coli Exceedance Objectives 9 (MPN/100mL) Los Angeles River Reaches 1-6 E.coli 253
10,000 Total coliform Los Angeles River 1000* Estuary Fecal coliform 400 Enterococcus 104 *When the ratio of fecal-to-total coliform exceeds 0.1
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
77 WATER RESOURCES PROGRESS METALS TMDL — WET WEATHER
Wet Weather Selenium (μg/L) No Target 5
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
78 WATER RESOURCES PROGRESS METALS TMDL — WET WEATHER
Wet Weather Copper (μg/L) No Target 67.32
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
79 WATER RESOURCES PROGRESS METALS TMDL — WET WEATHER
Wet Weather Lead (μg/L) No Target 62
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
80 WATER RESOURCES PROGRESS METALS TMDL — WET WEATHER
Wet Weather Zinc (μg/L) No Target 159
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
81 WATER RESOURCES PROGRESS METALS TMDL — WET WEATHER
Wet Weather Cadmium (μg/L) No Target 3.1
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
82 WATER RESOURCES PROGRESS BACTERIA TMDL — WET WEATHER
Wet Weather Bacteria (Exceedance Days Allowed per year) 15 Single Sample E.coli Exceedance Objectives 17 (MPN/100mL) Los Angeles River Reaches 1-6 E.coli 253
10,000 Total coliform Los Angeles River 1000* Estuary Fecal coliform 400 Enterococcus 104 *When the ratio of fecal-to-total coliform exceeds 0.1
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf
83 WATER RESOURCES PROGRESS BENEFICIAL USES ALONG THE LA RIVER Rare Potential Cold Warm Threatened Freshwater Freshwater Wetland Wildlife Endangered Aquatic Spawning Existing Habitat Habitat Marine Habitat Estuary Habitat Species Migration Reproduction (WARM) (WARM) (MAR) (WET) (EST) (WILD) (RARE) (MIGR) (SPWN)
Canoga Park 51 51 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 1 Long Beach 0 0
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
84 WATER RESOURCES PROGRESS BENEFICIAL USES ALONG THE LA RIVER
Potential Municipal and Industrial Industrial Water Non-Water Domestic Process Service Ground Water Commercial Shellfish Contact Contact Existing Supply Supply Supply Recharge Navigation Sport Fishing Harvesting Recreation Recreation (MUN) (PROC) (IND) (GWR) (NAV) (COMM) (SHELL) (REC-1) (REC-2)
Canoga Park 51 51 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 1 Long Beach 0 0
Source: Basin Plan for the Coast Watersheds of Los Angeles and Ventura Counties, Los Angeles Regional Water Quality Control Board, 2018
85 WATER RESOURCES PROGRESS WATER QUALITY TOTAL MAXIMUM DAILY LOAD (TMDL)
Dry Weather Dry Weather Dry Weather Dry Weather Bacteria Total Discharge Average Copper Lead Selenium (Exceedance Days Annual Dry-Weather Volume (acre-feet) (μg/L) (μg/L) (μg/L) Allowed per Year)
1,000,000 500,000 0 500,000 1,000,000 Canoga Park 51 51 650 AFY 50 49 48 Reseda 47 47 30 19 5 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 26 10 37 36 35 34 Burbank 33 33 32 Glendale 31 31 23 30 29 28 12 5 27 26 26 25 24 No Target 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 22 11 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 23 12 3 2 No Target No Target 9 1 Long Beach 0 0
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf 86 WATER RESOURCES PROGRESS WATER QUALITY TOTAL MAXIMUM DAILY LOAD (TMDL)
Wet Weather Total Discharge Wet Weather Wet Weather Wet Weather Wet Weather Bacteria Driest / Average / Wettest Lead Selenium Cadmium Zinc (Exceedance Days Annual Wet-Weather Volume (acre-feet) (μg/L) (μg/L) (μg/L) (μg/L) Allowed per Year)
1,000,000 500,000 0 500,000 1,000,000 Canoga Park 51 51 3,300 / 15,000 / 47,000 AFY 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 63 5 3.1 159 15 27 26 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 50,000 / 280,000 / 950,000 AFY No Target No Target No Target No Target 17 1 Long Beach 0 0
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf 87 WATER RESOURCES PROGRESS WATER QUALITY TOTAL MAXIMUM DAILY LOAD (TMDL)
Total Discharge Average Annual Ammonia Nitrate Nitrite Nitrate +Nitrite Trash Dry / Wet-Weather Volume (acre-feet) (mg N/L) (mg N/L) (mg N/L) (mg N/L) (lb)
1,000,000 500,000 0 500,000 1,000,000 Canoga Park 51 51 15,000 / 650 AFY 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 1.6 40 39 38 Studio City 37 37 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 8 1 8 0 25 24 23 Downtown LA 22 22 21 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 2.4 14 13 South Gate 12 12 11 10 Compton 9 9 8 7 6 5 4 3 2 1 Long Beach 0 280,000 / 51,000 AFY 0
Source: LA County MS4 Permit Attachment O, https://www.waterboards.ca.gov/rwqcb4/water_issues/programs/stormwater/municipal/la_ms4/Dec5/Order%20R4-2012-0175%20-%20Final%20Attachment%20O.pdf 88 PROGRESS WATER SUPPLY
Source: Olin
89 WATER RESOURCES PROGRESS THE LA RIVER DRAINS AN 834-SQUARE-MILE WATERSHED
Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community
90 WATER RESOURCES PROGRESS LA RIVER WATERSHED MEAN ANNUAL PRECIPITATION 1981-2010
38.7 in / 983 mm
LA River Max (19.6 in / 500 mm) LA River Min (13.1 in / 332 mm) 12.9 in / 327 mm
Source: PRISM Climate Group, Oregon State University, 30-yr Normal Precipitation: Annual, 2015
91 WATER RESOURCES PROGRESS THE LA RIVER WATERSHED EXPERIENCES DISTINCT SEASONAL AND ANNUAL PRECIPITATION PATTERNS Annual Precipitation Variability
Seasonal Precipitation Variability (1971-2000): Upper River Middle River Lower River (Woodland Hills Pierce College) (Los Angeles Downtown USC Campus) (Los Angeles Daugherty Airport)
Source: Western Regional Climate Center, Cooperative Climatological Data Summaries, 2018
92 WATER RESOURCES PROGRESS FLOW IN THE LA RIVER IS IMPACTED BY WATER RECLAMATION PLANTS
Tillman WRP: RM 43 (+42 cfs) Burbank WRP: RM 31 (+7 cfs) Los Angeles-Glendale WRP: RM 29 (+12 cfs)
Average Dry-Weather Flow: Cubic Feet per Second (cfs) 5 cfs (3,600 AFY)
71 cfs (50,000 AFY)
Source: Geosyntec
93 WATER RESOURCES PROGRESS HYDROLOGIC DRIVERS ARE DIVERSE Upper Los Angeles River Area Watermaster: San Fernando Basin Sylmar Basin Verdugo Basin Eagle Rock Basin Water Replenishment District of Southern California: Central Basin West Coast Basin Main San Gabriel Basin Watermaster: Main San Gabriel Basin Raymond Basin Management Board: Raymond Basin Under SGMA Process: Water Reclamation Plant North Central Basin Arbor Restoration (Approximate) Hollywood Basin (Low Priority) Significant Bird Habitat Santa Monica Basin Tidal Influence Area and Sea Level Rise
Source: LACDPW GIS Data Portal; Geosyntec, 2018
94 WATER RESOURCES PROGRESS TRIBUTARY AREAS
Direct Tributary Area < 1mi2 at the head 207 mi2 at the mouth
Total Tributary Area 40 mi2 at the head 834 mi2 at the mouth
Cumulative Direct Drainage Area to the LA River River Mile 51 River Mile 0 Cumulative Total Drainage Area to the LA River River Mile 51 River Mile 0
Source: LACDPW LSPC Model Input, 2012
95 WATER RESOURCES PROGRESS ESTIMATED EXISTING DRY WEATHER FLOW AT MOUTH: 51,000 ACRE-FEET PER YEAR
Assumptions: 80
70 -D.C. Tillman WRP Discharge = 42 cfs 60 -LA/Glendale WRP Discharge = 12.1 cfs 50 -Burbank Tillman WRP Discharge = 7 cfs 40
-Upwelling Flow (total) = 5.6 cfs 30
-Dry Weather Urban Flow = 84 gpd/imp ac 20 ( ) -Evaporation Rate (Upstream of RM 24) = 0.50 in/d (0.021 in/hr) 10
-Evaporation Rate (Downstream of RM 24) = 0.41 in/d (0.017 in/hr) 0
-Additional ET in ARBOR Reach = 0 -10
-20 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1
R M
Upwelling LAG WRP Incidental Urban Runoff Burbank WRP Evapotranspiration DC Tillman WRP
Source: Adapted from OneWater LA 2040 Plan
96 WATER RESOURCES PROGRESS ESTIMATED POSSIBLE FUTURE DRY WEATHER FLOW AT MOUTH: 1,000 ACRE-FEET PER YEAR
Assumptions: 80
70 -D.C. Tillman WRP Discharge = 0 (all recycled) 60 -LA/Glendale WRP Discharge = 0 (all recycled) 50 -Burbank Tillman WRP Discharge = 0 (all recycled) 40 (groundwater management enhanced by 50%) -Upwelling Flow (total) = 2.8 cfs 30
-Dry Weather Urban Flow = 42 gpd/imp. ac. (50% of EWMP/WMP dry weather 20 ( ) targets by 2038) 10
-Evaporation Rate (Upstream of RM 24) = 0.63 in/d (0.026 in/hr) 0
-Evaporation Rate (Downstream of RM 24) = 0.51 in/d (0.021 in/hr) -10
-Additional ET in ARBOR Reach = 0 -20 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1
R M
Upwelling Evapotranspiration Incidental Urban Runoff
Source: Geosyntec
97 WATER RESOURCES PROGRESS ESTIMATED PLAUSIBLE FUTURE DRY WEATHER FLOW AT MOUTH: 10,000 ACRE-FEET PER YEAR
Assumptions: 80
70 -DC Tillman WRP Discharge = 14 cfs (20,000 AF (28 cfs) for groundwater recharge) 60 -LA/Glendale WRP Discharge = 4 cfs (reduced proportionally to Tillman) 50 -Burbank Tillman WRP Discharge = 2.3 cfs (reduced proportionally to Tillman) 40 (management of groundwater by LADWP) -Upwelling Flow (total) = 0 cfs 30
-Dry Weather Urban Flow = 0 gpd/imp ac (EWMP/WMP dry weather targets by 2038) 20 ( ) -Evaporation Rate (Upstream of RM 24) = 0.50 in/d (0.021 in/hr) 10
-Evaporation Rate (Downstream of RM 24) = 0.41 in/d (0.017 in/hr) 0
-Additional ET in ARBOR Reach = 0 -10
-20 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1
R M
DC Tillman WRP LAG WRP Evapotranspiration Burbank WRP
Source: Geosyntec
98 WATER RESOURCES PROGRESS ESTIMATED EXISTING AND POSSIBLE FUTURE DRY WEATHER FLOW AT MOUTH:
Estimated Existing: 51,000 acre-feet per year Plausible Future: 10,000 acre-feet per year Possible Future: 1,000 acre-feet per year
80 80 80
70 70 70
60 60 60
50 50 50
40 40 40
30 30 30
20 20 20 ( ) ( ) ( ) 10 10 10
0 0 0
-10 -10 -10
-20 -20 -20 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1
R M R M R M
Upwelling LAG WRP DC Tillman WRP LAG WRP Upwelling Evapotranspiration Incidental Urban Runoff Burbank WRP Evapotranspiration Burbank WRP Incidental Urban Runoff Evapotranspiration DC Tillman WRP
Source: Adapted from OneWater LA 2040 Plan, Geosyntec
99 WATER RESOURCES PROGRESS WET WEATHER FLOWS AT MOUTH
Average Volume of Wet Weather Events: Average Wet Weather Volumes at Mouth 1,000,000 280,000 acre-feet 900,000 800,000 700,000 Wettest Year - 2005: 600,000 950,000 acre-feet 500,000 400,000 ( - ) 300,000 Driest Year - 2007 200,000 100,000 50,000 acre-feet 0
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011
W Y
Note: Flow volumes are calculated from Los Angeles County Watershed Model. Comparison of modeled flow volumes with USGS gage 11103000 at Los Angeles River above Long Beach for the period of available overlapping record (WY1989 - WY1992) indicates modeled annual flow volumes are typically within approximately 1% of measured annual flow volumes (LACDPW, 2010, Figure 84).
Source: LACDPW, 2010, Los Angeles County Watershed Model Configuration and Calibration --Part I: Hydrology, LADWP, 2015, Stormwater Capture Master Plan, August 2015. Prepared by Geosyntec
100 WATER RESOURCES PROGRESS GROUNDWATER BASINS
Upper Los Angeles River Area Watermaster: San Fernando Basin Sylmar Basin Verdugo Basin Eagle Rock Basin Water Replenishment District of Southern California: Central Basin Forebay West Coast Basin Main San Gabriel Basin Watermaster: Main San Gabriel Basin Raymond Basin Management Board: Raymond Basin Under SGMA Process: North Central Basin Hollywood Basin (Low Priority) Santa Monica Basin
Source: Los Angeles County GIS Data Portal, Ground Water Basins, 2014; SGMA, 2016
101 WATER RESOURCES PROGRESS DEPTH TO GROUND WATER
High (25 ft)
Low (425 ft)
Source: Adapted from B3 Insight database compilation, https://www.b3insight.com/
102 WATER RESOURCES PROGRESS GROUNDWATER BASINS Groundwater Production Wells (Existing & Historical) Upper Los Angeles River Area Watermaster: San Fernando Basin Sylmar Basin Verdugo Basin Eagle Rock Basin Water Replenishment District of Southern California: Central Basin Forebay West Coast Basin Main San Gabriel Basin Watermaster: Main San Gabriel Basin Raymond Basin Management Board: Raymond Basin Under SGMA Process: North Central Basin Hollywood Basin (Low Priority) Santa Monica Basin
Source: GAMA GIS Database, https://www.waterboards.ca.gov/water_issues/programs/gama/online_tools.html
103 WATER RESOURCES PROGRESS GROUNDWATER BASINS AVAILABLE STORAGE San Fernando Basin Central Basin West Coast Basin
- San Fernando Basin: 600,000 acre-feet
- Amended Judgment for Central Basin allows for use of 330,000 acre-feet of unused storage space along with increased pumping
- Amended Judgment for West Coast Basin allows for use of 120,000 acre-feet of unused storage space along with increased pumping
Source: GAMA GIS Database, https://www.waterboards.ca.gov/water_issues/programs/gama/online_tools.html
104 S F W LACDPW W 4896A 1000 900 G S E WATER RESOURCES 800 PROGRESS 700 600 500 400
UPPER LOS ANGELES ( ) E RIVER300 AREA: 200 SAN FERNANDO BASIN 100
1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 20022004200620082010 2012 2014 2016 2018 2020
Maximum Safe Yield: M R S Total: ~86,000 acre ft per year 0 -Native Water: 43,660 acre-feet per year -100 -Imported Credits: 43,000 acre-feet per year -200 600,000 -300 M R S Available Storage Space (in 2016): -400 600,000 acre-feet -500
(1,000 - ) (1,000 -600
C C S C -700
-800
1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 20022004200620082010 2012 2014 2016 2018 2020
Fall 1954 - Beginning of historic overdraft - Storage = -210,000 AF
Source: ULARA Annual WatermasterReport, 2015-16 Water Year, December 2017
105 WATER RESOURCES PROGRESS
Annual Spreading Operations in the ANNUAL SPREADING San Fernando Basin City of Los Angeles County Department of Public Works (Native + City of Los Angeles (Imported) Rainfall GRAND Burbank (inches) Water Imported1) (acre-feet) (acre-feet) 1 TOTAL (Imported) Weighted Year (acre-feet) Pacoima Average Branford Hansen Lopez Pacoima Tujunga TOTAL Headworks Tujunga TOTAL (acre-feet) Valley/Mtns 2015-16 547 1,137 42 1,298 523 3,548 0 0 0 3,548 306 10.05 VARIES FROM YEAR 2014-15 529 922 1 1,254 268 2,974 0 1 1 2,975 150 12.68 2013-14 474 1,667 661 7,442 195 10,439 0 4 4 10,443 7,000 7.98 2012-13 570 1,758 501 7,015 927 10,771 0 11 11 10,782 6,703 8.72 2011-12 529 9,357 104 3,482 101 13,573 0 4 4 13,577 1,371 11.55 2010-11 690 19,064 3,922 24,164 31,476 79,316 0 4 4 79,320 11,187 25.21 TO YEAR 2009-10 535 16,766 274 9,080 12,849 39,504 0 7,509 7,509 47,013 34 20.55 2008-09 706 0 1 2,000 7,233 9,940 0 0 0 9,940 --- 12.58 2007-08 570 10,517 634 5,025 4,892 21,638 0 0 0 21,638 --- 17.27 2006-07 532 5,762 44 436 1,200 7,974 0 0 0 7,974 --- 5.36 2005-06 576 20,840 958 7,346 14,895 44,615 0 0 0 44,615 --- 17.42 2004-05 1,448 33,301 940 17,394 21,115 74,198 0 0 0 74,198 --- 45.66 2003-04 444 6,424 144 1,731 1,322 10,065 0 0 0 10,065 --- 12.21 2002-03 932 9,427 518 3,539 1,914 16,330 0 0 0 16,330 --- 21.22 2001-02 460 1,342 0 761 101 2,664 0 0 0 2,664 --- 6.64 2000-01 562 11,694 172 3,826 1,685 17,939 0 0 0 17,939 --- 22.29 1999-00 468 7,487 578 2,909 2,664 14,106 0 0 0 14,106 --- 16.77 1998-99 547 8,949 536 696 3,934 14,662 0 0 0 14,662 --- 10.83 The long-term average amount of 1997-98 641 28,129 378 20,714 11,180 61,042 0 77 77 61,119 --- 38.51 1996-97 415 9,808 724 5,768 6,406 23,121 0 51 51 23,172 --- 17.65 spreading in the San Fernando Basin is 1995-96 345 8,232 363 4,532 7,767 21,239 0 0 0 21,239 --- 14.48 1994-95 585 35,137 1,086 14,064 18,236 69,108 0 0 0 69,108 --- 33.08 1993-94 462 12,052 182 3,156 4,129 19,981 0 0 0 19,981 --- 11.86 approximately 30,000 acre-feet per year. 1992-93 389 26,186 1,312 17,001 19,656 64,544 114 0 114 64,658 --- 41.26 1991-92 653 15,461 1,094 12,914 9,272 39,394 230 0 230 39,624 --- 32.39 1990-91 509 11,489 241 3,940 2,487 18,666 52 0 52 18,718 --- 7.69 1989-90 327 2,029 90 1,708 0 4,154 0 0 0 4,154 --- 9.55 1988-89 255 3,844 308 1,306 0 5,713 0 0 0 5,713 --- 9.72 1987-88 352 17,252 1,037 4,520 0 23,161 0 0 0 23,161 --- 21.36 1986-87 0 7,311 141 467 0 7,919 0 33 33 7,952 --- 7.7 1985-86 290 18,188 1,735 6,704 0 26,917 0 1,433 1,433 28,350 --- 23.27 1984-85 244 13,274 104 3,375 0 16,997 0 5,496 5,496 22,493 --- 13.31 1983-84 213 10,410 0 3,545 0 14,168 0 24,115 24,115 38,283 --- 11.18 1982-83 883 35,192 1,051 22,972 10,580 70,678 10 32,237 32,247 102,925 --- 46.07 1981-82 345 14,317 243 5,495 0 20,400 3,853 0 3,853 24,253 --- 20.16 1980-81 245 14,470 335 3,169 0 18,219 4,652 9,020 13,672 31,891 --- 12.89 1979-80 397 31,087 1,097 15,583 0 48,164 5,448 19,931 25,379 73,543 --- 33.66 1978-79 295 24,697 1,018 12,036 0 38,046 2,463 31,945 34,408 72,454 --- 24.07 1977-78 2,142 28,123 445 20,472 12,821 64,003 3,200 18,247 21,447 85,450 --- 44.84 1976-77 377 2,656 63 1,943 0 5,039 3,142 16 3,158 8,197 --- 16.02 1975-76 470 3,128 562 1,308 0 5,468 3,837 5,500 9,337 14,805 --- 14.2 1974-75 681 5,423 915 2,476 0 9,495 4,070 9,221 13,291 22,786 ------1973-74 672 6,287 946 2,378 0 10,283 6,205 0 6,205 16,488 ------1972-73 1,271 9,272 0 6,343 2,274 19,160 5,182 0 5,182 24,342 ------1971-72 161 1,932 0 1,113 0 3,206 7,389 0 7,389 10,595 ------1970-71 507 11,657 727 4,049 0 16,940 6,804 399 7,203 24,143 ------1969-70 674 11,927 0 1,577 2,380 16,558 11,021 0 11,021 27,579 ------1968-69 461 32,464 893 14,262 13,052 61,132 6,698 3,676 10,374 71,506 ------AVG. 552 13,647 587 6,851 5,034 26,671 1,653 3,754 5,407 32,078 4,824
1. Spreading by Burbank began in 2009-10 Water Year following completion of the Burbank MWD connection. These volumes are reported by LACDPW spreading data, and are therefore included in the “Grand Total column.
Source: ULARA Annual Watermaster Report: 2015-16 Water Year, Table 2-5: Annual Spreading Operations in the San Fernando Basin, 2017
106 WATER RESOURCES PROGRESS WATER REPLENISHMENT DISTRICT: CENTRAL BASIN AND WEST COAST BASIN WRD GROUNDWATER ASINS
Natural Safe Yield 0 -100 173,400 acre-feet per year -200 -300 Historical Average Replenishment -400 180,000 acre-feet per year -500 O AOD -600 Accumulated Overdraft (AOD) -700
Optimal AOD: 612,000 acre-feet A - ) (1,000 -800 M AOD Minimum AOD: 900,000 acre-feet -900 A O (AOD) O A -1000 -1100
1962 1964 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 200020022004200620082010 2012 2014 2016
Source: WRD Engineering and Survey Report, 2018
107 WATER RESOURCES PROGRESS WATER REPLENISHMENT DISTRICT: CENTRAL BASIN AND WEST COAST BASIN
Historic amounts of replenishment in the Central and West Coast Basins averages 200,000 180,000 acre-feet per year 180,000 8% 160,000 2%
140,000 29% 120,000
100,000 22% 80,000
60,000 ACRE-FEET PER YEAR (AFY) PER YEAR ACRE-FEET 40,000 39%
20,000 0 HISTORICAL AVERAGE (1959-2016) IMPORTED WATER RECYCLED WATER LOCAL WATER MAKEUP WATER IN-LIEU Source: WRD Engineering and Survey Report Table D, 2018
108 WATER RESOURCES PROGRESS
Historical Amounts of Water Recharge in the STORMWATER AND RIVER Montebello Forebay Spreading Grounds (in acre-ft) Imported Water Recycled Water Local Water Make-up Water Water San Total Year LACFCD Whittier Jose Pomona Stormwater and USGVMWD & or WRD Total Total CBMWD Total WRP Creek WRP River Baseflow SGVMWD Other WRP 1959-60 80,900 80,900 - - 20,064 100,964 BASEFLOW CAPTURE 1960-61 80,800 67,000 147,800 - - 9,118 156,918 1961-62 39,500 168,622 208,122 1,178 1,178 39,548 248,848 1962-63 4,800 75,790 80,590 12,405 12,405 14,565 107,560 1963-64 - 104,900 104,900 13,258 13,258 9,992 128,150 1964-65 75,500 84,670 160,170 14,528 14,528 13,097 187,795 1965-66 67,800 53,900 121,700 15,056 15,056 45,754 6,500 6,500 189,010 1966-67 74,100 10,200 84,300 16,223 16,223 59,820 160,343 VARIES YEAR TO YEAR 1967-68 66,600 28,800 95,400 18,275 18,275 39,760 153,435 1968-69 12,500 5,300 17,800 13,877 13,877 119,395 151,072 1969-70 25,800 43,100 68,900 17,158 17,158 52,917 138,975 1970-71 46,700 25,400 72,100 19,494 3,232 22,726 44,757 - 139,583 1971-72 - 34,400 34,400 17,543 4,456 21,999 17,688 - 74,087 1972-73 - 71,947 71,947 13,622 8,327 5,937 27,886 45,077 - 20,000 20,000 164,910 1973-74 - 68,237 68,237 13,385 7,064 3,003 23,452 29,171 - 23,921 23,921 144,781 1974-75 - 71,900 71,900 14,650 6,549 5,592 26,791 29,665 - - - 128,356 1975-76 - 50,800 50,800 12,394 9,062 6,231 27,687 22,073 - - - 100,560 1976-77 - 9,300 9,300 10,158 12,705 6,496 29,359 19,252 14,500 6,900 21,400 79,311 1977-78 - 39,900 39,900 13,104 5,997 6,621 25,722 147,317 7,800 - 7,800 220,739 1978-79 - 65,300 65,300 10,716 11,741 6,403 28,860 68,859 - - - 163,019 1979-80 - 10,200 10,200 14,568 9,815 5,023 29,406 106,820 10,900 - 10,900 157,326 1980-81 3,300 28,700 32,000 11,464 14,645 5,613 31,722 50,590 31,500 - 31,500 145,812 1981-82 - 4,600 4,600 14,133 15,285 4,634 34,052 47,930 30,900 - 30,900 117,482 The long-term average amount of 1982-83 - 2,000 2,000 12,818 4,217 5,735 22,770 126,076 8,900 - 8,900 159,746 1983-84 - 1,500 1,500 13,194 14,590 4,457 32,241 60,710 20,800 - 20,800 115,251 1984-85 - 40,600 40,600 12,905 14,093 4,380 31,378 39,099 - - - 111,077 stormwater and river baseflow captured 1985-86 - 21,500 21,500 13,827 11,487 3,965 29,279 66,966 - - - 117,745 1986-87 - 49,200 49,200 15,280 20,041 2,655 37,976 27,613 - 6,500 6,500 121,289 1987-88 - 23,300 23,300 14,585 27,182 1,582 43,349 50,068 5,800 - 5,800 122,517 and recharged in the Montebello Forebay 1988-89 - 50,300 50,300 13,830 33,327 2,616 49,773 17,096 6,500 - 6,500 123,669 1989-90 - 52,700 52,700 15,043 33,498 1,568 50,109 9,388 13,600 - 13,600 125,797 1990-91 - 56,300 56,300 13,841 38,603 1,420 53,864 35,717 100 - 100 145,981 Spreading Grounds is approximately 1991-92 - 43,100 43,100 12,620 31,326 2,957 46,903 136,357 - - - 226,360 1992-93 - 16,561 16,561 11,026 29,811 8,027 48,864 147,699 - - - 213,124 1993-94 - 20,411 20,411 10,249 40,768 2,965 53,981 55,896 - - - 130,288 50,000 acre-feet per year. 1994-95 - 21,837 21,837 10,642 18,431 4,228 33,300 100,578 - - - 155,715 1995-96 - 18,012 18,012 9,971 40,922 2,969 53,862 62,920 - - - 134,794 1996-97 - 22,738 22,738 9,850 36,977 3,132 49,959 58,262 - - - 130,959 1997-98 - 952 952 8,378 26,483 2,156 37,017 96,706 - - - 134,675 1998-99 - - - 10,968 34,782 1,451 47,201 32,013 - - - 79,214 1999-00 - 45,037 45,037 8,950 30,481 3,839 43,270 20,607 - - - 108,914 2000-01 - 23,451 23,451 8,253 35,165 2,925 46,343 39,725 - - - 109,519 2001-02 - 41,268 41,268 8,474 50,194 1,928 60,596 18,607 (c) - - 120,471 2002-03 - 17,297 17,297 5,156 35,320 2,320 42,796 63,271 (d) - - 123,364 2003-04 - 27,520 27,520 (e) 8,195 34,033 2,697 44,925 30,467 - - - 102,912 2004-05 - 25,296 25,296 (e) 6,741 20,547 2,215 29,503 148,674 - - - 203,473 2005-06 - 33,229 33,229 8,868 30,180 2,973 42,022 60,377 - - - 135,628 2006-07 - 40,214 40,214 7,334 34,823 2,882 45,039 11,495 - - - 96,748 2007-08 1,510 - 1,510 (b) 6,212 29,131 4,424 39,767 54,518 - - - 95,795 2008-09 - - - 5,202 29,999 4,410 39,611 35,348 - - - 74,959 2009-10 - 26,286 26,286 5,431 45,538 4,762 55,731 35,398 - - - 117,415 2010-11 - 37,315 37,315 7,576 24,323 5,231 37,131 113,295 - - - 187,741 2011-12 - - - 7,558 43,479 4,760 55,797 36,155 - - - 91,952 2012-13 - - - 7,004 47,207 4,933 59,145 6,048 - - - 65,193 2013-14 - - - 7,733 43,556 4,357 55,646 0 - - - 55,646 2014-15 - 18,515 18,515 4,811 35,737 3,802 44,349 15,892 - - - 78,757 2015-16 - 23,961 23,961 6,480 48,529 2,802 57,811 14,183 (f) - - 95,956 2016-17 - 32,693 32,693 6,956 47,761 3,350 58,067 70,027 (g) - - 160,786 Total 579,810 1,956,059 2,535,869 623,150 1,223,731 184,114 2,030,995 2,950,480 157,800 57,321 215,121 7,732,466 Average 44,601 38,354 47,847 11,128 27,194 3,917 36,268 50,870 13,150 14,330 14,341 133,318
(a) Includes the Rio Hondo Spreading Grounds, Whitter Narrow Conservation Pool, San Gabriel Spreading Groups and unlined San Gabriel River below Station F263. (b) CBMWD purchased 1,510 af of imported water for spreading for Downey, Lakewood, and Cerritos. (c) Includes 1,607 af of EPA extracted groundwater from WNOU considered lower area replenishment water paid for by WRD in 2003. (d) Includes 5,069 af of EPA extracted groundwater from WNOU considered lower area replenishment water paid for by WRD in June 2005. (e) Includes 13,000 af of water banked by Long Beach under storage agreement with WRD (792 af 02/03, 12,210 af 3/04). (f) Includes 206 af of DTSC extracted groundwater from WNOU considered lower area replenishment water paid for by WRD in 2017. (g) Includes 1,400 af of DTSC extracted groundwater from WNOU considered lower area replenishment water paid for by WRD in 2018.
Source: Water Replenishment District of Southern California (WRD), Engineering Survey and Report, Table A, Historical Amounts of Water Recharged in the Montebello Forebay Spreading Grounds2018
109 WATER RESOURCES PROGRESS
Historical Amounts of Replenishment Water for WATER REPLENISHMENT Central and West Coast Basins (AF) Montebello Forebay Spreading Water Injection Water* In-lieu Water year Total Imported Recycled Makeup Imported Recycled Local Water Total Total Total Water Water Water Water Water 1959-60 80,900 - 20,064 - 100,964 3,700 - 3,700 104,664 1960-61 147,800 - 9,118 - 156,918 4,420 - 4,420 161,338 VARIES YEAR TO YEAR 1961-62 208,122 1,178 39,548 - 248,848 4,460 - 4,460 253,308 1962-63 80,590 12,405 14,565 - 107,560 4,150 - 4,150 111,710 1963-64 104,900 13,258 9,992 - 128,150 10,450 - 10,450 138,600 1964-65 160,170 14,528 13,097 - 187,795 35,780 - 35,780 223,575 1965-66 121,700 15,056 45,754 6,500 189,010 47,760 - 47,760 745 237,515 1966-67 84,300 16,223 59,820 - 160,343 46,450 - 46,450 851 207,644 1967-68 95,400 18,275 39,760 - 153,435 43,790 - 43,790 850 198,075 1968-69 17,800 13,877 119,395 - 151,072 40,730 - 40,730 850 192,652 1969-70 68,900 17,158 52,917 - 138,975 33,220 - 33,220 900 173,095 1970-71 72,100 22,726 44,757 - 139,583 35,380 - 35,380 881 175,844 1971-72 34,400 21,999 17,688 - 74,087 40,100 - 40,100 756 114,943 1972-73 71,947 27,886 45,077 20,000 164,910 40,920 - 40,920 901 206,731 1973-74 68,237 23,452 29,171 23,921 144,781 41,510 - 41,510 901 187,192 1974-75 71,900 26,791 29,665 - 128,356 36,030 - 36,030 400 164,786 1975-76 50,800 27,687 22,073 - 100,560 44,250 - 44,250 400 145,210 1976-77 9,300 29,359 19,252 21,400 79,311 48,430 - 48,430 400 128,141 1977-78 39,900 25,722 147,317 7,800 220,739 39,400 - 39,400 16,131 276,270 1978-79 65,300 28,860 68,859 - 163,019 33,600 - 33,600 18,378 214,997 1979-80 10,200 29,406 106,820 10,900 157,326 36,660 - 36,660 14,961 208,947 1980-81 32,000 31,722 50,590 31,500 145,812 33,840 - 33,840 23,823 203,475 The long-term average amount of 1981-82 4,600 34,052 47,930 30,900 117,482 33,900 - 33,900 18,883 170,265 1982-83 2,000 22,770 126,076 8,900 159,746 43,240 - 43,240 19,752 222,738 1983-84 1,500 32,241 60,710 20,800 115,251 38,080 - 38,080 41,740 195,071 replenishment water in the Central and 1984-85 40,600 31,378 39,099 - 111,077 36,080 - 36,080 36,840 183,997 1985-86 21,500 29,279 66,966 - 117,745 29,830 - 29,830 26,132 173,707 West Coast Basins is approximately 1986-87 49,200 37,976 27,613 6,500 121,289 36,430 - 36,430 29,202 186,921 1987-88 23,300 43,349 50,068 5,800 122,517 35,310 - 35,310 28,411 186,238 1988-89 50,300 49,773 17,096 6,500 123,669 31,860 - 31,860 25,425 180,954 178,000 acre-feet per year. 1989-90 52,700 50,109 9,388 13,600 125,797 30,125 - 30,125 29,151 185,073 1990-91 56,300 53,864 35,717 100 145,981 27,891 - 27,891 22,039 195,911 1991-92 43,100 46,903 136,357 - 226,360 33,246 - 33,246 19,104 278,710 1992-93 16,561 48,864 147,699 - 213,124 29,776 - 29,776 53,306 296,206 1993-94 20,411 53,981 55,896 - 130,288 23,800 - 23,800 109,581 263,669 1994-95 21,837 33,300 100,578 - 155,715 22,109 1,480 23,589 50,898 230,202 1995-96 18,012 53,862 62,920 - 134,794 21,293 4,170 25,463 51,333 211,590 1996-97 22,738 49,959 58,262 - 130,959 21,112 6,241 27,353 39,394 197,706 1997-98 952 37,017 96,706 - 134,675 15,621 8,306 23,927 30,330 188,932 1998-99 - 47,201 32,013 - 79,214 18,619 6,973 25,591 23,516 128,321 1999-00 45,037 43,270 20,607 - 108,914 21,210 7,460 28,670 22,278 159,862 2000-01 23,451 46,343 39,725 - 109,519 21,621 6,838 28,459 21,181 159,159 2001-02 41,268 60,596 18,607 - 120,471 22,144 7,276 29,420 20,720 170,611 2002-03 17,297 42,796 63,271 - 123,364 21,920 6,192 28,112 11,205 162,681 2003-04 27,520 44,925 30,467 - 102,912 19,269 3,669 22,938 - 125,850 2004-05 25,296 29,503 148,674 - 203,473 15,975 3,920 19,895 7,804 231,172 2005-06 33,229 42,022 60,377 - 135,628 14,298 6,620 20,918 9,889 166,435 2006-07 40,214 45,039 11,495 - 96,748 11,451 12,912 24,363 9,264 130,375 2007-08 1,510 39,767 54,518 - 95,795 11,597 14,690 26,287 - 122,082 2008-09 - 39,611 35,348 - 74,959 15,873 10,123 25,996 - 100,955 2009-10 26,286 55,731 35,398 - 117,415 17,752 11,432 29,184 - 146,599 2010-11 37,315 37,131 113,295 - 187,741 13,363 11,285 24,648 6,724 219,113 2011-12 - 55,797 36,155 - 91,952 10,082 8,312 18,394 7,815 118,161 2012-13 - 59,145 6,048 - 65,193 14,707 11,240 25,947 2,180 93,320 2013-14 - 55,646 - - 55,646 13,677 17,587 31,263 4,371 91,280 2014-15 18,515 44,349 15,892 - 78,757 10,013 17,345 27,358 12,723 118,838 2015-16 23,961 57,811 14,183 - 95,956 8,105 17,152 25,257 - 121,213 2016-17 32,693 58,067 70,027 - 160,786 11,092 15,587 26,679 - 187,465 Total 2,535,869 2,030,995 2,950,480 215,121 7,732,466 1,507,501 216,810 1,724,309 873,319 10,330,094 Average 47,847 36,268 51,763 14,341 133,318 25,991 9,427 29,729 18,985 178,105
* Does not include Alamitos Barrier water purchased by the Orange County Water District for the Orange County Basin Source: Water Replenishment District of Southern California (WRD), Engineering Survey and Report, Table D, Historical Amounts of Replenishment Water for Central and West Coast Basins
110 WATER RESOURCES PROGRESS WATER REPLENISHMENT DISTRICT: CENTRAL BASIN AND WEST COAST BASIN
Historical Direct Water Use in WRD Service Area Historic direct water use in the WRD service area averages 620,000 acre-feet per year 700,000
600,000 3%
500,000
400,000 56%
300,000
200,000 ACRE-FEET PER YEAR (AFY) PER YEAR ACRE-FEET 41% 100,000
0 HISTORICAL AVERAGE (1930-2016) GROUNDWATER IMPORTED WATER RECLAIMED WATER PRODUCTION FOR DIRECT USE FOR DIRECT USE
Source: WRD Engineering and Survey Report Table F, 2018
111 WATER RESOURCES PROGRESS DIRECT WATER USE IN THE WATER REPLENISHMENT DISTRICT SERVICE AREA
In the past 30 years, annual direct water use has steadily decreased DIRECT WATER USE IN THE WRD SER ICE AREA • Annual imported water has decreased 800000 by approximately 200,000 acre-feet • Annual recycled water has increased 700000 to approximately 35,000 acre-feet 600000
500000
400000
A - 300000
200000
100000
0
1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015
GROUNDWATER IMPORTED WATER RECLAIMED WATER PRODUCTION FOR DIRECT USE FOR DIRECT USE Source: WRD Engineering and Survey Report Table F, 2018
112 WATER RESOURCES PROGRESS 2016-17 TOTAL OVERLYING DEMAND IN WRD SERVICE AREA WAS 487,000 AF
Groundwater Production 350,000 • Central Basin: 183,000 acre-feet • West Cost Basin: 27,000 acre-feet 300,000 14,000
Adjudicated Pumping 250,000 101,000 • Central Basin: Allowable Pumping Allocation (APA) of 217,367 acre-feet per year 200,000 • West Coast Basin: Annual Pumping Rights 23,000 of 64,468 acre-feet per year 150,000 183,000 139,000 Amended Judgments 100,000 • Amended Judgements provide mechanisms for use and (AFY) PER YEAR ACRE-FEET management of storage and increased pumping 50,000 -Central Basin: 330,000 acre-feet 27,000 -West Coast Basin: 120,000 acre-feet 0 CENTRAL BASIN WEST COAST BASIN • Development of projects, management of storage and increased pumping can offset overlying demands for imported water and increase regional local water supply WATER RIGHTS EXTRACTION IMPORTED WATER RECYCLED WATER
Source: Central Basin Watermaster Report, 2017; West Coast Basin Watermaster Report, 2017
113 WATER RESOURCES PROGRESS RECHARGE PATHWAYS VARY
Confined Aquifer Unconfined Aquifer
Source: LADWP SCMP
114 WATER RESOURCES PROGRESS HYDRAULIC CONDUCTIVITY: SOILS ACCEPT WATER AT VARYING RATES
Hydrologic Soil Group Class A (Ksat > 1.42 in/hr) Class B (0.57 in/hr < Ksat ≤ 1.42 in/hr) Class C (0.06 in/hr < Ksat ≤ 0.57 in/hr) Class D (Ksat ≤ 0.06 in/hr) Not Available
Source: USDA Natural Resources Conservation Service Web Soil Survey, 2018
115 WATER RESOURCES PROGRESS RECHARGE: SURFACE SPREADING VS INJECTION
Geophysical Categories Category A - Most Conducive to Recharge Category B - Somewhat Conducive to Recharge Category C - Least Conducive to Recharge
Source: Geosyntec
116 WATER RESOURCES PROGRESS FLOOD CONTROL AND WATER CONSERVATION RESERVOIRS
Dams and Reservoirs
1: Sawpit Dam 11: Lopez Dam 21: Big Tujunga Dam 31: Legg Lake 2: Highland Dam 12: Sepulveda Dam 22: Sierra Madre Dam 32: Burbank Reservoir No.4 3: Chevy Chase 968 Reservoir 13: Burbank Reservoir No. 1 23: Ascot Dam 33: Glorietta Reservoir 4: Glorietta Reservoir 14: Glenoaks 968 Reservoir 24: Brand Park Reservoir 34: San Fernando Reservoir 5: Whittier Narrows Dam 15: Western Reservoir 25: Green Verdugo Dam 35: Los Angeles Reservoir 6: Santa Anita Dam 16: Burbank Reservoir No. 5 26: Elysian Dam 36: Van Norman Bypass Reservoir 7: Devil’s Gate Dam 17: Garvey Reservoir 27: Pacoima Dam 37: Chatsworth Reservoir 8: Laguna 18: Encino Dam 28: Morris S. Jones Res. 38: Magic Johnson Lake 9: Eagle Rock Dam 19: Sawpit Debris Basin 29: Lincoln Park Lake 10: Hansen Dam 20: Eaton Wash Dam 30: Peck Road Park Lake
Source: LA County GIS Portal
117 WATER RESOURCES PROGRESS EXISTING AND PROPOSED SPREADING GROUNDS AND INJECTION WELLS Proposed Spreading Ground Existing Spreading Ground Facility LADWP Watershed Management SB-P1 Planned/In-development Existing Existing Seawater Barrier Injection Wells Proposed Seawater Barrier Injection Wells
E1: Arroyo Seco S.G. E12: Rio Hondo Coastal Basin S.G. N1: Spulveda Dam Spreading Ground SB-E1: West Coast Basin E2: Branford S.B. E13: Santa Anita S.G. N2: Bull Creek Area Spreading Ground Barrier Project E3: Buena Vista S.B. E14: Santa Fe Reservoir S.G. N3: Browns Creek Area Spreading Ground E4: Dominguez Gap S.G. E15: Sawpit S.G. N4: Tujunga Spreading Ground Enhancement E5: Eaton S.B. E16: Sierra Madre S.G. E6: Eaton S.G. E17: Tujunga Gallery S.G. E7: Hansen S.G. E18: Tujunga S.G. E19: Whittier Narrows W.C. Diversion Canal SB-E2: Dominguez Gap E9: Lopez S.G. Barrier Project SB-E3: Alamitos E10: Pacoima S.G. Barrier Project E11: Peck Road S.B.
Source: LA County GIS Portal, LADWP SCMP, LA Basin Study (2016), https://www.usbr.gov/lc/socal/basinstudies/LABasin.html
118 WATER RESOURCES PROGRESS SPECIFIC CAPACITY
Specific Capacity (gpm/ft drawdown) 1-25 25-50 50-75 75-100 100-200 > 200 Water Replenishment District Boundary Existing and Historic Wells
Source: Traced from Figure 3: Water Replenishment District of Southern California, Technical Bulletin Volume 2 ~ Winter, 2005 & GAMA GIS Database, https://www.waterboards.ca.gov/water_issues/programs/gama/online_tools.html
119 WATER RESOURCES PROGRESS TRIBUTARY AREA
Total/Direct Total/Direct LAR Watershed LAR Watershed Drainage Area Groundwater Drainage Area (River Right/Left) Basins
Canoga Park 51 51 2 2 2 50 40/<1 mi 15/<1 mi 25/<1 mi 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 Tujunga Wash Tujunga Wash 37 2 2 +224 mi +224 mi ULARA 36 35 34 Burbank 33 33 32 Glendale 31 31 Verdugo Wash Verdugo Wash 30 2 2 +25 mi +25 mi 29 28 27 26 25 Arroyo Seco Arroyo Seco 24 +47 mi2 +47 mi2 23 Downtown LA 22 22 21 Forebay 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 12 South Gate 12 Rio Hondo 2 Central Basin 11 +142 mi 10 Compton 9 9 8 7 6 Compton Creek Compton Creek 5 2 2 +42 mi +42 mi 4 West Coast Basin 3 2 834/207 mi2 134/71 mi2 698/135 mi2 1 Long Beach 0 0
120 WATER RESOURCES PROGRESS LA RIVER FLOWS
Total Discharge Total Discharge Total Discharge Total Discharge Average Annual Average Annual Driest Year Wettest Year Dry-Weather Volume Wet-Weather Volume Wet-Weather Volume Wet-Weather Volume Groundwater (acre feet) (acre feet) (acre feet) (2007) (acre feet) (2007) Basins
Canoga Park 51 51 650 AFY 15,000 AFY 3,300 AFY 50,000 AFY 50 49 48 Reseda 47 47 46 45 Van Nuys 44 44 43 42 Sherman Oaks 41 41 40 39 38 Studio City 37 37 ULARA 36 35 34 Burbank 33 33 32 Glendale 31 31 30 29 28 27 26 25 24 23 Downtown LA 22 22 21 Forebay 20 19 Vernon 18 18 17 16 15 Bell Gardens 14 14 13 South Gate 12 12 Central 11 Basin 10 Compton 9 9 8 7 6 5 4 West Coast 3 2 Basin 1 Long Beach 0 51,000 AFY 280,000 AFY 50,000 AFY 950,000 AFY 0
121 WATER RESOURCES PROGRESS VALUE OF RECHARGED WATER
1, 00
1,200
1,000
800 $/af 00
00
200
0 201 201 2018 201 2020 2021 2022 2023 202 202 202 202 2028 202 2030 2031 2032 2033 203 203
U re e T er 1 W er C D r Pre e e LRP C D r Source: LADWP Stormwater Capture Master Plan, 2015
122 PROGRESS
123