LLos Anggeless Bassin SStormmwater CConsservvation Study PPlan of SStudy UU.S. Departmment of the Innterior Loss Angeles Coounty Countty of Los Anggeles BBureau of Reeclamation Floood Control DDistrict Deparrtment of Pubblic Works SSouthern Callifornia Area Office Alhhambra, California Alhammbra, Californnia Februuary 2013 Mission Statements The U.S. Department of the Interior protects America’s natural resources and heritage, honors our cultures and tribal communities, and supplies the energy to power our future. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest o f the American public. The mission of the County of Los Angeles Department of Public Works is to provide public infrastructure and municipal services to protect and enrich the daily lives of over 10 million people in Los Angeles County. LLos AAngeeles Basin Stoormwwater CConsservaationn Study PPlan off Study PPrepared by GGreg Jaquez CCounty of Loss Angeles Deppartment of PPublic Works LLos Angeles CCounty Flood Control Distrrict WWatershed Maanagement DDivision AAlhambra, Caalifornia AAmy Witheralll UU.S. Department of the Inteerior BBureau of Recclamation SSouthern California Area OOffice TTemecula, Caalifornia UU.S. Departmment of the Innterior Loss Angeles Coounty Countty of Los Anggeles BBureau of Reeclamation Floood Control DDistrict Deparrtment of Pubblic Works SSouthern Callifornia Area Office Alhhambra, California Alhammbra, Californnia Februuary 2013 Table of Contents Page Abbreviations and Acronyms .............................................................................. v  Executive Summary ............................................................................................. 1  1.0  Introduction .............................................................................................. 5  1.1  Study Purpose ................................................................................ 5  1.2  Study Objectives ............................................................................ 5  1.3  Description of Basin Study Area ................................................... 5  2.0  Study Description..................................................................................... 7  2.1  Project Background ........................................................................ 7  2.2  Previous Work and Available Data and Models ............................ 7  2.3  Current Local Stormwater Activities ............................................. 9  2.4  Resource Availability..................................................................... 10  2.5  Interested Parties ............................................................................ 10  3.0  Study Organization and Public Involvement ........................................... 13  3.1  Basin Study Structure .................................................................... 13  3.2  Public Involvement Plan ................................................................ 17  4.0  Study Tasks .............................................................................................. 19  4.1  Description of Tasks ...................................................................... 20  5.0  Schedule and Milestones.......................................................................... 27  6.0  Budget ...................................................................................................... 28  Appendix 1 – Map Figures .................................................................................. 32  Appendix 2 – Groundwater Basin and Water Agency Relationships .................. 35  Appendix 3 – Stakeholders Outreach List .......................................................... 39  Appendix 4 – Watershed Facilities Study List ................................................... 41  Appendix 5 – Public Involvement Plan ............................................................... 47  Tables Table 1. Summary of Letters of Support and Contributors ................................ 11 Table 2. ELT Representatives ............................................................................. 13 Table 3. STAC Representatives .......................................................................... 14 Table 4. Study Technical Teams ......................................................................... 16 iii Abbreviations and Acronyms Basin Study Watershed-level study authorized by the Secure Water Act, Public Law 111-11 to assess the risk of climate change to water resources in the west’s major river basins. CA DWR California Department of Water Resources DB Debris Basin DRI Debris Retention Inlet ELT Executive Leadership Team Gateway Gateway Water Management Authority GLAC Greater Los Angeles County GWAM Groundwater Augmentation Model HSPF Hydrologic Simulation Program-Fortran IPRP Independent Peer Review Panel IRWM Integrated Regional Water Management IRWMP Integrated Regional Water Management Plan LACDPW Los Angeles County Department of Public Works LACFCD Los Angeles County Flood Control District LADWP City of Los Angeles Department of Water and Power Master Plan Stormwater Capture Master Plan MWD Metropolitan Water District of Southern California PM Project Manager(s) Reclamation U.S. Department of the Interior, Bureau of Reclamation SG Spreading Grounds STAC Stakeholder Technical Advisory Committee STT Study Technical Teams ULARA Upper Los Angeles River Area USACE U.S. Army Corps of Engineers WAS Los Angeles Basin Water Augmentation Study v Los Angeles Basin Stormwater Conservation Study Watersheds The Los Angeles River, San Gabriel River, Ballona Creek, South Santa Monica Bay, North Santa Monica Bay, and Dominguez Channel/Los Angeles Harbor watersheds WMMS Watershed Management Modeling System vi Executive Summary Imported water supplies to Los Angeles County, California, are uncertain due to periodic droughts in northern California and the Colorado River Basin, court decisions related to endangered species in the Bay Delta, and potential allocations of Colorado River water. Changing demographics, climate variability, and the competing interest for available water present additional long-term risks to the stability and reliability of imported water. Accordingly, various Los Angeles area agencies with water management authority, such as the Los Angeles County Flood Control District (LACFCD),1 are actively pursuing a strategy aimed at achieving water independence by developing local water resources such as stormwater. The LACFCD is the primary agency for conducting groundwater replenishment operations in Los Angeles County. In typical years, the LACFCD infiltrates more than 270,000 acre-feet of captured stormwater, imported water, and recycled water into the various groundwater basins in Los Angeles County. In wetter years, that number can exceed 700,000 acre-feet and, in drier years, may be little more than 150,000 acre-feet. LACFCD partnered with the U.S. Department of the Interior, Bureau of Reclamation’s (Reclamation) Southern California Area Office to study long-term flood control and water conservation impacts from projected population and climate conditions. The Los Angeles Basin Stormwater Conservation Study (Basin Study) will recommend potential changes to the operation of stormwater capture systems, modifications to existing facilities, and development of new facilities that could help resolve future flood control and water supply issues. The Los Angeles River, San Gabriel River, Ballona Creek, South Santa Monica Bay, North Santa Monica Bay, and Dominguez Channel/Los Angeles Harbor watersheds (Watersheds) are the focus of this Basin Study (figure 1). This study incorporates the entire watershed boundaries, including where they extend outside Los Angeles County. The Watersheds share attributes such as overlapping municipal and water agency boundaries, an interconnected flood control system, and a common planning purpose with major ongoing planning efforts like the Greater Los Angeles County Integrated Regional Water Management Plan (IRWMP), Gateway IRWMP and the Metropolitan Water District Integrated Resources Plan. 1 The Los Angeles County Flood Control Act of 1915. The Act established the Los Angeles Flood Control District and empowered it to provide flood protection, water conservation, recreation, and aesthetic enhancement within its boundaries. The Flood Control District is governed, as a separate entity, by the County of Los Angeles Board of Supervisors. 1 Los Angeles Basin Stormwater Conservation Study Figure 1. Watersheds included in the Basin Study: Los Angeles River, San Gabriel River, Ballona Creek, South Santa Monica Bay, North Santa Monica Bay, Dominguez Channel/Los Angeles Harbor. The Basin Study watersheds include more than 9 million people and encompass 1,900 square miles and 6 major groundwater basins. According to the California Department of Finance, the State’s population as a whole is projected to increase by more than 35 percent while Los Angeles County’s is projected to increase by approximately 18 percent by 2050. Projected larger population growth rates outside of Los Angeles County portends enormous pressure and competition for import sources of water and the need for increased development of local water supply sources. At 2