Los Angeles Basin Stormwater Conservation Study: Task 3.2 Hydrologic Modeling Report

U.S. Bureau of Reclamation (USBR) | December 3rd, 2013

The Los Angeles County Flood Control District (LACFCD) partnered with the U.S. Department of the Interior, Bureau of Reclamation (Reclamation) to collaborate on t

The Los Angeles County Flood Control District (LACFCD) partnered with the U.S. Department of the Interior, Bureau of Reclamation (Reclamation) to collaborate on the Los Angeles Basin Stormwater Conservation Study (LA Basin Study). The purpose of the LA Basin Study is to investigate long-range water conservation and flood control impacts caused by projected changes in climate conditions and population in the Los Angeles region. The LA Basin Study will recommend potential modifications or changes in the operation of the existing stormwater capture systems, and the development of new facilities that could help resolve future water supply and flood control issues. These recommendations will be developed by identifying alternatives and conducting trade-off analyses. For Task 3, Downscaled Climate Change and Hydrologic Modeling of the LA Basin Study, Reclamation developed downscaled climate change projections, while LACFCD applied these projections to generate the future hydrology. LACFCD utilized the Watershed Management Modeling System (WMMS) to perform the hydrologic modeling for the LA Basin Study. This report summarizes the data, methods, and results of the historic and future hydrologic modeling. The purpose of Task 3.2, Hydrologic Modeling is to simulate hydrology with respect to climate change for the Los Angeles River, San Gabriel River, Ballona Creek, South Santa Monica Bay, North Santa Monica Bay, Malibu Creek, and Dominguez Channel/Los Angeles Harbor watersheds (Basin Study Watersheds). This study incorporates the entire watershed boundaries, including where they extend outside of Los Angeles County. The following sub-tasks were identified to achieve this objective: Historic Hydrologic Modeling (Water Year 1987 through 2000) Determine baseline scenario modeling assumptions Prepare WMMS to simulate baseline scenario Perform WMMS baseline simulations Analyze and summarize WMMS results Projected Hydrologic Modeling (Water Year 2012 through 2095) Determine future scenario modeling assumptions Prepare WMMS to simulate future scenarios Perform WMMS simulations Analyze and summarize WMMS results

Los Angeles Basin Stormwater Conservation Study: Task 4 Existing Infrastructure Response & Operations Guidelines Analysis

U.S. Bureau of Reclamation (USBR) | September 1st, 2014

The Los Angeles County Flood Control District (LACFCD) partnered with the U.S. Department of the Interior, Bureau of Reclamation (Reclamation) to collaborate on the Los A

The Los Angeles County Flood Control District (LACFCD) partnered with the U.S. Department of the Interior, Bureau of Reclamation (Reclamation) to collaborate on the Los Angeles Basin Stormwater Conservation Study (LA Basin Study). The purpose of the LA Basin Study is to investigate long-range water conservation and flood risk impacts caused by projected changes in climate conditions and population in the Los Angeles region. The LA Basin Study will recommend potential modifications or changes in the operation of the existing stormwater capture systems as well as the development of new facilities that could help resolve future water supply and flood risk issues. These recommendations will be developed by identifying alternatives and conducting trade-off analyses.  For Task 4, Existing Infrastructure Response and Operations Guidelines Analysis of the LA Basin Study, Reclamation, the U.S. Army Corps of Engineers (USACE), and the LACFCD jointly analyzed the major components of the water conservation and flood risk mitigation system. For the analysis, Reclamation assessed the 14 major LACFCD dams and reservoirs, USACE analyzed their 4 major flood control dams in the region, and LACFCD assessed the 26 major spreading grounds interconnected to the water conservation system. The LACFCD also evaluated 5 major channel outlets. This report summarizes the data, methods, and results of the existing infrastructure response to the historic climate and future projections.  The purpose of Task 4 is to assess the response of existing infrastructure and analyze the operation guidelines under both the current and future climate conditions. It is important to recognize that this effort relies upon the existing configuration of the water conservation and flood risk mitigation network as the baseline condition.  This evaluation includes a ranking assessment of the current and future stormwater volumes conserved or discharged, and other impacts to the water conservation and flood risk mitigation system. The following sub-tasks were identified to conduct this assessment:  Response to Current Climate (Water Year 1987 through 2000)  Analyze stormwater volumes conserved or discharged Analyze infrastructure response and operations guidelines  Response to Future Climate (Water Year 2012 through 2095) Analyze stormwater volumes conserved or discharged Analyze infrastructure response and operations guidelines The response to the current climate provided a representation of the existing situation and revealed how the existing infrastructure could reasonably be expected to perform under a historical climate to which the region has become accustomed. However, this may not be the case in the future. The response to future climate assessed the existing infrastructure under varying climate conditions to understand if it would function satisfactorily. This analysis of the existing infrastructure served as a status quo assessment of historical conditions as well as a “no action” evaluation of the future.  After the analysis of the historic and future climate conditions, an assessment was conducted for the system of dams and spreading ground facilities. A water conservation ranking—or performance level—was developed to assess the overall efficiency and resilience of the facilities to both the historic and projected future climate. Although results are assigned to the individual 18 dams/reservoirs and 26 spreading grounds, each facility was analyzed within the entire system. The dams and spreading grounds were ranked according to their performance with respect to one another; these rankings were used to develop the Task 4 performance levels.  Generally, facilities that were the least efficient resulted in being the least resilient to climate change and were assigned Performance Level III which has a high potential for enhancements. Facilities that were generally more efficient were more resilient to climate change and were assigned Performance Level II. Finally, facilities that were the most efficient tended to be the most resilient to climate change and were assigned to Performance Level I.  For the channel outlet analysis, assessment levels were developed to determine which of the five major channel outlets have the highest potential for increasing stormwater capture and reducing runoff to the Pacific Ocean. The ability to reduce the stormwater runoff that is lost to the ocean and capture it would greatly boost the potential stormwater supply in this region. The Task 4 analysis assigned assessment levels to the 5 major channel outlets and their respective watersheds.  The Los Angeles River ranked into Assessment Level III indicating that this watershed has the greatest potential for increasing stormwater supplies and should be targeted for future enhancements. For the remaining outlets, although these locations were found to have lower discharge volumes, additional capture efforts should still be targeted within these watersheds to further increase stormwater capture and improve local water supplies. 

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

U.S. Bureau of Reclamation (USBR) | December 1st, 2015

The Los Angeles Basin Stormwater Conservation Study (LA Basin Study) is a collaborative partnership between the Los Angeles County Flood Control District (LACFCD) and the

The Los Angeles Basin Stormwater Conservation Study (LA Basin Study) is a collaborative partnership between the Los Angeles County Flood Control District (LACFCD) and the U.S. Department of the Interior, Bureau of Reclamation (Reclamation). The purpose of the LA Basin Study is to investigate long-range water conservation and flood risk management impacts caused by projected changes in the climate and population in the Los Angeles region. The LA Basin Study provides recommendations for potential modifications and changes to the existing regional stormwater capture system, as well as for the development of new facilities and practices, which could help to resolve future water supply and flood risk management issues. The stormwater capture concepts and alternatives developed within this report will inform the Task 6 – Trade-Off Analysis & Opportunities report of the LA Basin Study.  The objective of Task 5, Infrastructure and Operations Concepts, is to identify and develop both structural and nonstructural (i.e., plans and policies) concepts to manage stormwater under projected climate conditions for the Los Angeles Basin watersheds, which include: Los Angeles River, San Gabriel River, South Santa Monica Bay, North Santa Monica Bay, Ballona Creek, Malibu Creek, and Dominguez Channel/Los Angeles Harbor watersheds (Basin Study Watersheds). The efforts and results previously completed for Task 2 – Water Supply & Water Demand Projections, Task 3 – Downscaled Climate Change & Hydrologic Modeling, and Task 4 – Existing Infrastructure Response & Operations Guidelines Analysis serve as the foundation for Task 5. The major tasks and subtasks of Task 5 include:  Concept Development  - Identify a range of opportunities and options using stakeholder input  - Determine preliminary concepts for further evaluation  Technical Analysis of Concepts  - Assess structural and nonstructural concepts pertaining to dams, spreading grounds, flood control channels, decentralized storage, infiltration, reuse facilities, debris basins, and other concepts  - Develop and apply concept selection criteria  Appraisal-Level Analysis  - Evaluate selected concepts for future system reliability, efficiency, and effectiveness  In addition to any new stormwater conservation concepts that are developed, the existing facilities from the Task 4 analysis were considered for enhancement. The Watershed Management Modeling System (WMMS), which has served as the primary hydrologic model throughout the LA Basin Study, continued to be the preferred tool and was also used for Task 5. Hydrologic simulations were conducted to analyze the potential water conservation and flood risk mitigation benefit for the various project concepts. For the future period, water years 2012 through 2095, four climate projections (Low 1, Low 2, Mid 2, and High 1) from Task 4 were used in the simulations.  Click here for USBR's Task 5 Appendices index: Appendix A - Infrastructure and Operations Concepts (Excel) Appendix B - Local Stormwater Capture (PDF)  Appendix C - Modeling Approach and Solutions (PDF) Appendix D - Local Management Cost (Excel) Appendix D - Regional 1 Cost (Excel) Appendix D - Regional 2 Cost (Excel) Appendix D - Regional 3 Cost (Excel) Appendix D - Storage 3 Cost (Excel) Appendix E - LACFCD Dam Hydrology and Cost Estimates (PDF)

Lower Tule River Irrigation District Groundwater Sustainability Agency Groundwater Sustainability Plan

Lower Tule River Irrigation District Groundwater Sustainability Agency | January 21st, 2020

Lower Tule River Irrigation District Groundwater Sustainability Plan San, Joaquin - Tule Subbasin

Lower Tule River Irrigation District Groundwater Sustainability Agency | July 19th, 2023

This Plan addresses the items identified in the SGMA regulations specific to the Agency, including descriptions of the physical characteristics, the water budget (histor

This Plan addresses the items identified in the SGMA regulations specific to the Agency, including descriptions of the physical characteristics, the water budget (historic and future), specific monitoring features and locations, quantifiable targets and minimum thresholds for depth to groundwater, groundwater storage, groundwater quality, and land subsidence between 2020 and 2040, and those projects and management actions proposed to implement during the 20 year planning horizon to achieve the Sustainability Goal.

Management of the Colorado River: Water Allocations, Drought, and the Federal Role

Congressional Research Service (CRS) | April 4th, 2024

From its headwaters in Colorado and Wyoming to its terminus in the Gulf of California, the Colorado River Basin covers more than 246,000 square miles. The basin spans sev

From its headwaters in Colorado and Wyoming to its terminus in the Gulf of California, the Colorado River Basin covers more than 246,000 square miles. The basin spans seven U.S. states (Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada, and California) and two countries (the United States and Mexico). Pursuant to federal law, the Bureau of Reclamation (Reclamation), a component of the Department of the Interior (DOI), plays a prominent role in the management of the basin’s waters. In the Lower Basin (i.e., Arizona, Nevada, and California), Reclamation also serves as water master on behalf of the Secretary of the Interior, a role that elevates the status of the federal government in basin water management. The federal role in managing Colorado River water is magnified by the multiple federally owned and operated water storage and conveyance facilities in the basin, which provide low-cost water and hydropower supplies.

Management of the Colorado River: Water Allocations, Drought, and the Federal Role

Congressional Research Service (CRS) | August 4th, 2022

Management of the Colorado River: Water Allocations, Drought, and the Federal Role

Congressional Research Service (CRS) | September 7th, 2022

Managing Drought in a Changing Climate: Four Essential Reforms

Public Policy Institute of California (PPIC) | September 12th, 2018

California’s climate is changing. Hotter temperatures, a shrinking snowpack, shorter and more intense wet seasons, rising sea level, and more volatile precipita

California’s climate is changing. Hotter temperatures, a shrinking snowpack, shorter and more intense wet seasons, rising sea level, and more volatile precipitation—with wetter wet years and drier dry years—are stressing the state’s water management system. Recent climate projections indicate that the pace of change will increase. To avoid unwanted social, economic, and environmental consequences, the water system will need to adapt to greater climate extremes and growing water scarcity. While California is making good progress in some areas of drought management, a more focused plan of action is needed. Successful adaptation will require strong leadership at the state and local levels, and cooperation on all fronts. The 2012–16 drought—the hottest in the state’s recorded history and one of the driest—offered a window into the future under a warming climate and lessons for managing future droughts. Using these lessons as a starting point, this report offers a road map of essential reforms to prepare for and respond to droughts in California’s changing climate. Key reforms include: Plan ahead. Stronger drought planning is critically important for urban water management, groundwater sustainability, safe drinking water in rural communities, and freshwater ecosystems. Upgrade the water grid. California needs a comprehensive program to address above- and below-ground storage, conveyance, and operational challenges by mid-century, including repairing facilities that are broken, expanding conveyance and storage capacity, and modernizing and integrating operations. Update water allocation rules. California should comprehensively update its water allocation governance. The goals should be to find equitable and efficient ways to allocate limited supplies among competing demands during dry times while promoting efforts to capture and store water during wet times. Find the money. Reliable funding is crucial for adapting to climate change. New sources are needed to pay for necessary water-management investments and to fill funding gaps in the state’s water system. The focus of this reform agenda is on drought, because drought―more than any other aspect of California’s climate―reveals the vulnerabilities of watermanagement systems. Importantly, these reforms will improve drought resilience for today’s conditions, not just for the future.

Martis Valley Groundwater Basin Sustainable Groundwater Management Act Alternative Submittal

Truckee Donner Public Utility District (TDPUD) | December 22nd, 2016

the Sustainable Groundwater Management Act (SGMA) is being submitted collaboratively by the Truckee Donner Public Utility District, Northstar Community Services District

the Sustainable Groundwater Management Act (SGMA) is being submitted collaboratively by the Truckee Donner Public Utility District, Northstar Community Services District, Placer County Water Agency, Placer County, Nevada County, and Town of Truckee. These six local public agencies (Local SGMA Agencies) serve water, have the authority to serve water, or have land-use authority in the Martis Valley Groundwater Basin (MVGB) and their overlapping jurisdictions cover 100% of the basin. There are no other water suppliers or land-use agencies in the MVGB eligible to comply with SGMA. The Truckee Donner Public Utility District Staff is serving as the Administering Manager for this Alternative Submittal.