Learning from Crises to Build Urban Water Security

Rand Corporation (Rand) | January 15th, 2025

In this report, the authors examine the experiences of five cities — Cape Town, South Africa; Melbourne, Australia; São Paulo, Brazil; and Las Vegas, Nevada, and New O

In this report, the authors examine the experiences of five cities — Cape Town, South Africa; Melbourne, Australia; São Paulo, Brazil; and Las Vegas, Nevada, and New Orleans, Louisiana, in the United States — facing severe or catastrophic water supply risks to identify steps that could be taken ahead of time to mitigate those risks and build urban water security.

Lessons from California’s 2012–2016 Drought

American Society of Civil Engineers (ASCE) | October 1st, 2018

California’s 5-year drought has ended, even as its aftermath lingers. From 2012–2016 much or all of California was under severe drought conditions, with gre

California’s 5-year drought has ended, even as its aftermath lingers. From 2012–2016 much or all of California was under severe drought conditions, with greatly diminished precipitation, snowpack, and streamflow and higher temperatures. Water shortages to forests, aquatic ecosystems, hydroelectric power plants, rural drinking water supplies, agriculture, and cities caused billions of dollars in economic losses, killed millions of forest trees, brought several fish species closer to extinction, and caused inconvenience and some expense to millions of households and businesses. The drought also brought innovations and improvements in water management, some of which will better prepare California for future droughts. This paper summarizes the magnitude and impacts of the 2012–2016 California drought. The paper then reviews innovations arising from the drought in the larger historical context of water management in California. Lessons for California and for modern drought management are then discussed. Droughts in modern, well-managed water systems serving globalized economies need not be economically catastrophic, but will always have impacts and challenges, particularly for native ecosystems. In California and every other water system, droughts usefully expose weaknesses and inadequate preparation in water management. In this regard for California, managers of ecosystems and small rural water supplies had the most to learn.

Letter to State Water Board re: Flow Criteria that use Percent of Unimpaired Flow

Delta Stewardship Council (Delta Council) | May 22nd, 2012

The proposed use of percent of unimpaired flow is a step toward improving the outlook for fish and other wildlife utilizing the San Joaquin River and its tributaries. Fal

The proposed use of percent of unimpaired flow is a step toward improving the outlook for fish and other wildlife utilizing the San Joaquin River and its tributaries. Fall-run Chinook salmon are likely to benefit from February-through-June flows that are more natural in timing and variability than current flows. Compared with the existing maze of flow standards for the San Joaquin River and its tributaries, unimpaired flow comes closer to approximating natural flow, and it does so more transparently. Caveats include: (1) flow is but one of many stressors affecting fish and wildlife; (2) the choice of flow criteria and metrics needs to serve the broader needs of ecosystems as well as individual species; (3) a chosen percentage of unimpaired flow may fall short of the minimum needed by fish and wildlife in some years; and (4) such critical years are likely to become more common as Sierra Nevada snowpacks diminish as a consequence of climate change. This qualified endorsement is based on our reading of the “Technical Report on the Scientific Basis for Alternative San Joaquin River Flow and Southern Delta Salinity Objectives” (State Water Resources Control Board, February 2012).

Levee Decisions and Sustainability for the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | August 15th, 2010

Linkages between land-use change and groundwater management foster long-term resilience of water supply in California

Journal of Hydrology: Regional Studies (Elsevier) | March 9th, 2022

Study Region: We created a 270-m coupled model of land-use and groundwater conditions, LUCAS-W[ater], for California’s Central Coast. This groundwater-dependent region

Study Region: We created a 270-m coupled model of land-use and groundwater conditions, LUCAS-W[ater], for California’s Central Coast. This groundwater-dependent region is undergoing a dramatic reorganization of groundwater management under California’s 2014 Sustainable Groundwater Management Act (SGMA). Study Focus: Understanding land-use and land-cover change supports long-term sustainable water management. Anthropogenic water demand has depleted groundwater aquifers worldwide, while future water shortages will likely affect land-use change, creating system feedbacks. Our novel participatory approach fused changes in land-use and associated water use from county-scale data to local water agencies’ estimates of total sustainable supply, scaling up local hydro-geologic knowledge from heterogeneous aquifers and diverse management approaches to a regional level. We assessed five stakeholder-driven scenarios with the same historic rates of urban and agricultural land-use change, but different water and land-use management, analyzing how management strategies altered both the spatial pattern of development and subsequent water sustainability from 2001 to 2061. New Hydrological Insights for the Region: Transformative strategies using demand-side interventions that coupled water availability to land use more effectively achieved long-term sustainability than adaptive strategies using supply-side interventions to increase water supplies. Limiting water withdrawals within SGMA regulated basins resulted in leakage of development into unregulated basins, increasing groundwater pumping there. Protecting ecosystems, farmlands, and recharge areas from development reduced leakage into undeveloped basins without negatively affecting water sustainability.

Liquid Assets: Improving Management of the State's Groundwater Resources

Legislative Analyst's Office (LAO) | March 24th, 2010

California’s water system is facing a series of challenges affecting water availability, reliability, and delivery. Reevaluating how groundwater is managed is necessary

California’s water system is facing a series of challenges affecting water availability, reliability, and delivery. Reevaluating how groundwater is managed is necessary if it is to achieve its full potential as a reliable source of water. In this report, we present the Legislature with a series of actions that would be phased in over a period of time to address current and emerging groundwater management issues, including bringing science and law together to accurately reflect the physical interconnection of surface water and groundwater.

Living with Water Scarcity

David Zetland | August 5th, 2014

“Don’t panic. It is easy to live with water scarcity. Use politics to allocate community water before using economics to ration commodity water," says author David Z

“Don’t panic. It is easy to live with water scarcity. Use politics to allocate community water before using economics to ration commodity water," says author David Zetland. Scarcity is a perception. Shortage is a fact. Most of us deal with scarcity every day. We spend our time going places, doing things and seeing people. We spend our money on products and services. We wouldn’t mind a bit more time and money, but at least we get some of what we want. Shortage is worse than scarcity because you can’t get any of what you want, even if you have time or money. Increasing water scarcity is forcing us to choose among competing wants. Some lucky people do not face these choices, but an increasing number do. Those people need to manage scarcity if they want to avoid shortage. This book is not about measuring scarcity, a perception that changes from one place to another and one community to another. This book describes appropriate solutions for living with—perhaps even thriving with — water scarcities in both quantity and quality.

Long-Term Operations of the Central Valley Project and State Water Project Draft Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | July 26th, 2024

The Bureau of Reclamation (Reclamation) prepared this Environmental Impact Statement (EIS) for the 2021 Endangered Species Act Reinitiation of Section 7 Consultation on t

The Bureau of Reclamation (Reclamation) prepared this Environmental Impact Statement (EIS) for the 2021 Endangered Species Act Reinitiation of Section 7 Consultation on the Long-Term Operation of the Central Valley Project (CVP) and State Water Project (SWP). This EIS is meant to inform the public and decision-makers on potential federal actions by examining a range of reasonable alternatives and the potential effect on the environment. Reclamation manages the Central Valley Project (CVP). The California Department of Water Resources (DWR) manages the State Water Project (SWP). Collectively, the operation of the CVP and SWP provides flood control and navigation, delivers water to 30 million people, supports 4 million acres of agriculture, maintains 19 wildlife refuges on the Pacific Flyway, protects numerous iconic and endemic species such as Chinook salmon, coho salmon, steelhead, sturgeon, and smelt, generates 4.5 million megawatt hours of electricity, maintains water quality for beneficial uses in the California Bay-Delta, and supports recreation throughout Northern California. This summary provides a succinct overview of the development of alternatives in coordination with other agencies and the public, major conclusions for key environmental resource areas, the identification of avoidance and mitigation measures to address potential impacts, and issues that have been in dispute as raised by the public and other interested parties. This summary provides the material required by the Council on Environmental Quality’s National Environmental Policy Act (NEPA) Implementing Regulations regarding the contents of an EIS summary. Click here to read Maven's Notebook background article to the new DEIS.

Los Angeles Basin Stormwater Conservation Study: Plan of Study

U.S. Bureau of Reclamation (USBR) | February 28th, 2013

Imported water supplies to Los Angeles County, California, are uncertain due to periodic droughts in northern California and the Colorado River Basin, court decisions r

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), 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. Related links: Los Angeles Basin Study Summary Report Task 2: Water Supply and Demand Analysis Click here for Reclamation's index of inter-related LA Basin Study reports and appendices.

Los Angeles Basin Stormwater Conservation Study: Task 3.1 Climate Change and Hydrologic Projections Appendices

U.S. Bureau of Reclamation (USBR) | October 1st, 2013

Reclamation’s Technical Service Center (TSC) performed Task 3.1 of the LA Basin Study—to develop and evaluate projected future climate conditions related to precipita

Reclamation’s Technical Service Center (TSC) performed Task 3.1 of the LA Basin Study—to develop and evaluate projected future climate conditions related to precipitation frequency over the Los Angeles Basin. The subtasks were to: Consider existing projections of climate change in the LA Basin Study area Determine appropriate climate scenarios for use in developing precipitation and potential evaporation input datasets to support subsequent hydrologic modeling Prepare data (hourly precipitation and potential evaporation) for input into the LACFCD’s Watershed Management Modeling System (WMMS) Determine storm event frequency for planning purposes The data, methods, and results from Task 3.1 are documented in this report. Results from these four subtasks were then transmitted to LACFCD, who used these results as input in their WWMMS as part of Task 3.2 of the LA Basin Study. LACFCD is preparing a companion report with the results from the hydrologic modeling.