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Los Angeles Basin Stormwater Conservation Study Task 5 Infrastructure & Operations Concepts Report

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Los Angeles Basin Stormwater Conservation Study Task 5 Infrastructure & Operations Concepts Report RECLAMATIONManaging Water in the West Los Angeles Basin Stormwater Conservation Study Task 5 Infrastructure & Operations Concepts Report U.S. Department of the Interior County of Los Angeles Los Angeles County Bureau of Reclamation Department of Public Works Flood Control District October 2015 Mission Statements 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. The mission of the Department of the Interior is to protect and provide access to our Nation’s natural and cultural heritage and honor our trust responsibilities to Indian Tribes and our commitments to island communities. 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 of the American public. Cover Photo: Morris Dam along the San Gabriel River, Los Angeles County, California. Los Angeles Basin Stormwater Conservation Study Task 5. Infrastructure & Operations Concepts Report October 2015 CH2M Kathleen Higgins, PE, Project Manager Richard Sturn, PG, Project Hydrogeologist Wilfred Hsu, PE, Project Engineer Nathaniel Summerville, PE, Project Engineer Bureau of Reclamation Lower Colorado Region Engineering Services Office Tom Nichols, PE, Supervisory Civil Engineer Robert Owen, PE, Civil Engineer County of Los Angeles Department of Public Works Los Angeles County Flood Control District Watershed Management Division Lee Alexanderson, PE, Associate Civil Engineer Daniel Bradbury, PE, Senior Civil Engineering Assistant Bureau of Reclamation Lower Colorado Region Southern California Area Office Jack Simes, Area Planning Officer Peer Reviewed by: Santa Ana Watershed Project Authority Mark Norton, Water Resources & Planning Manager Acknowledgments Main San Gabriel Basin Watermaster Pomona Valley Protective Association c/o City of Upland Six Basins Watermaster Los Angeles Basin Study Task 5. Infrastructure & Operations Concepts Contents Page EXECUTIVE SUMMARY .................................................................................................. 11 CONCEPT DEVELOPMENT ......................................................................................................... 12 TECHNICAL ANALYSIS OF CONCEPTS ....................................................................................... 12 APPRAISAL-LEVEL ANALYSIS .................................................................................................... 13 LOCAL SOLUTIONS .................................................................................................................... 15 REGIONAL SOLUTIONS .............................................................................................................. 16 STORAGE SOLUTIONS ............................................................................................................... 16 MANAGEMENT SOLUTIONS ........................................................................................................ 17 STORMWATER CAPTURE FINDINGS .......................................................................................... 18 Stormwater Conservation ................................................................................................. 18 Capital and Operational Costs ......................................................................................... 19 Other Project Characteristics and Benefits .................................................................... 20 1. INTRODUCTION ............................................................................................................. 1 1.1. STUDY PURPOSE ................................................................................................................. 1 1.2. STUDY BACKGROUND .......................................................................................................... 1 1.3. DESCRIPTION OF STUDY AREA ............................................................................................ 2 1.4. OBJECTIVES AND OUTCOMES OF TASK 5 ............................................................................ 5 1.5. HYDROLOGY MODELS USED FOR STUDY ............................................................................ 6 1.5.1. Bounding and Future Climate Projections ............................................................. 6 2. METHODS ...................................................................................................................... 8 2.1. CONCEPT DEVELOPMENT .................................................................................................... 8 2.2. TECHNICAL ANALYSIS OF CONCEPTS ................................................................................ 13 2.2.1. Technical Criteria Development ............................................................................ 13 2.2.2. Technical Analysis .................................................................................................. 18 2.3. APPRAISAL-LEVEL ANALYSIS ............................................................................................. 22 2.3.1. Analysis Criteria ...................................................................................................... 23 2.3.2. Concept Planning .................................................................................................... 23 2.3.3. Local Solutions ........................................................................................................ 28 2.3.4. Regional Solutions .................................................................................................. 35 2.3.5. Storage Solutions .................................................................................................... 37 2.3.6. Management Solutions........................................................................................... 52 3. APPRAISAL-LEVEL ANALYSIS RESULTS AND DISCUSSION ............................... 58 3.1. LOCAL SOLUTIONS ............................................................................................................. 58 3.1.1. Local Stormwater Capture ..................................................................................... 58 3.1.2. Low Impact Development ...................................................................................... 61 3.1.3. Complete Streets .................................................................................................... 63 3.2. REGIONAL SOLUTIONS ....................................................................................................... 66 3.2.1. Regional Stormwater Capture ............................................................................... 66 3.2.2. Stormwater Conveyance Systems ....................................................................... 72 3.2.3. Alternative Capture ................................................................................................. 77 3.3. STORAGE SOLUTIONS ........................................................................................................ 81 3.3.1. LACFCD Dams ........................................................................................................ 81 3.3.2. USACE Dams .......................................................................................................... 92 3.3.3. Debris Basins ........................................................................................................... 95 3.4. MANAGEMENT SOLUTIONS ................................................................................................ 98 3.4.1. Stormwater Policies ................................................................................................ 99 iii Los Angeles Basin Study Task 5. Infrastructure & Operations Concepts 3.4.2. Green Infrastructure Programs ........................................................................... 101 3.4.3. Regional Impact Programs .................................................................................. 103 4. STORMWATER CAPTURE FINDINGS ..................................................................... 107 4.1. STORMWATER CONSERVATION ....................................................................................... 107 4.2. CAPITAL AND OPERATIONAL COSTS................................................................................ 110 4.3. OTHER PROJECT CHARACTERISTICS AND BENEFITS ..................................................... 112 5. REFERENCES ............................................................................................................ 115 Figures Page Figure ES-1. Los Angeles Basin Stormwater Conservation Study Conceptual Project Groups ........................................................................................................................................ 14 Figure ES-2. Stormwater Conservation Comparison by Conceptual Project Groups ............. 21 Figure ES-3. Cost per Acre Foot Conserved Comparison by Conceptual Project Groups ..... 22 Figure 1. Los Angeles Basin Stormwater Conservation Study Watersheds .............................. 3 Figure 2. LA Basin Study Major Groundwater Basins ............................................................... 4 Figure 3. LACFCD Flood Control and Water Conservation Facilities ........................................ 4 Figure 4. Projected Climate Scenario Subset – Annual Stormwater Runoff ............................. 7 Figure
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