Water Recommendations to the Next President

Pacific Institute | September 14th, 2020

The United States faces several severe and worsening water problems. Continuing to neglect these problems will impoverish and sicken this and future generations,

The United States faces several severe and worsening water problems. Continuing to neglect these problems will impoverish and sicken this and future generations, destroy beneficial aquatic ecosystems, and threaten our economy and food supply. Smart water policies will create hundreds of thousands of jobs, improve public health, and speed our economic recovery. In this letter, we offer a short assessment of four key problems and specific recommendations for addressing them.

Water requirement of Urban Green Infrastructure under climate change

Science of the Total Environment (Elsevier) | June 16th, 2023

The increased uncertainty of rainfall and high urban temperatures resulting from climate change present challenges for water management in Urban Green Infrastructure (UGI

The increased uncertainty of rainfall and high urban temperatures resulting from climate change present challenges for water management in Urban Green Infrastructure (UGI). UGI is an important component of cities, and it plays a crucial role in addressing various environmental issues (e.g., floods, pollutants, heat islands, etc.). Effective water management of UGI is essential to ensure its environmental and ecological benefits in the face of climate change. However, previous studies have not adequately investigated water management strategies for urban-scale GI under climate change scenarios. This study aims to estimate the current and future water requirement and effective rainfall (rainwater stored in the soil and plant roots available for plant evaporation) to determine the irrigation requirement of UGI during periods of rainfall deficit under current and future climate conditions. The results indicate that the water requirement for UGI will continue to increase under both RCP4.5 and RCP8.5 climate scenarios, with a higher increase projected under RCP8.5. For instance, the average water requirement for UGI is currently 731.29 mm, and it is projected to increase to 756.45 mm (RCP4.5) and 816.47 mm (RCP8.5) in summer during the period of 2081–2100, assuming low managed water stress condition. In addition, the water requirement of UGI in Seoul is the highest in June (approximately 125–137 mm) and the lowest in December or January (about 5–7 mm). While irrigation is unnecessary in July and August due to sufficient rainfall, other months in Seoul require irrigation when rainfall is insufficient. For example, continuous insufficient rainfall from May to June 2100 and April to June 2081 would need >110 mm (RCP4.5) of irrigation requirement even under high managed water stress condition. The findings of this study provide a theoretical foundation for water management strategies in current and future UGI settings.

Water Resilience Plan: Rapid Assessment -- Preliminary Identification of Needs and Strategies with Significant Impact on the Region’s Water

Los Angeles County Department of Public Works (LACDPW) | May 1st, 2017

This document represents one of the items set forth in the Water Resilience Work Plan presented to the Board of Supervisors in June 2016. The Rapid Assessment pre

This document represents one of the items set forth in the Water Resilience Work Plan presented to the Board of Supervisors in June 2016. The Rapid Assessment presents some of the early findings of the research to identify the most promising approaches and related financial need. As a piece of the larger Water Resilience Plan, a first draft of which Public Works plans to present to the Board in summer 2017, the Rapid Assessment provides a targeted snapshot of the research outcomes and underscores the greatest perceived needs relevant to building regional water resilience. The context of climate change and unpredictable rainfall in Southern California has greatly diminished the reliability of imported water supplies and our ability to replenish groundwater in recent years. This new reality calls for practical, effective strategies to access significant amounts of locally available water to supplement and build resilience in the region’s water supply . Currently, the County of Los Angeles manages to capture and store enough stormwater to meet the demand of one and a half million residents each year. Research has shown that implementation of a portfolio of regional stormwater capture projects could increase this amount between two- and three-fold by ensuring the region can capitalize on less regular, more intense rain events. While other sustainable sources of water should be considered and integrated into a comprehe nsive water management strategy for the region, stormwater represents an accessible, abundant resource with limited funding opportunities. Potable and recycled water are underwritten by ratepayer revenue that also supports improvement and expansion of related infrastructure. Available funding for existing stormwater capture supports current County operations and maintenance, but is insufficient for any significant expansion. Desalination has limited dedicated funding , but relies on costly treatment options that have unclear environmental impacts for the region. Significant investment in regional stormwater capture projects would have substantial impact on local water supply while contributing to improvements in overall watershed health. Stormwater capture strategies, in particular, provide unparalleled opportunities to improve water quality and enhance communities through the integration of multi-benefit approaches. New funding opportunities will be necessary to facilitate the design, implementation, and operations of centralized projects with regional benefits.

Water shortage risks from perennial crop expansion in California’s Central Valley

Environmental Research Letters (IOP) | October 15th, 2019

California’s Central Valley is one of the world’s most productive agricultural regions. Its high-value fruit, vegetable, and nut crops rely on surface water imports

California’s Central Valley is one of the world’s most productive agricultural regions. Its high-value fruit, vegetable, and nut crops rely on surface water imports from a vast network of reservoirs and canals as well as groundwater, which has been substantially overdrafted to support irrigation. The region has undergone a shift to perennial (tree and vine) crops in recent decades, which has increased water demand amid a series of severe droughts and emerging regulations on groundwater pumping. This study quantifies the expansion of perennial crops in the Tulare Lake Basin, the southern region of the Central Valley with limited natural water availability. A gridded crop type dataset is compiled on a 1-square mile spatial resolution from a historical database of pesticide permits over the period 1974–2016 and validated against aggregated county-level data. This spatial dataset is then analyzed by irrigation district, the primary spatial scale at which surface water supplies are determined, to identify trends in planting decisions and agricultural water demand over time. Perennial crop acreage has nearly tripled over this period, and currently accounts for roughly 60% of planted area and 80% of annual revenue. These trends show little relationship with water availability and have been driven primarily by market demand. From this data, we focus on the increasing minimum irrigation needs each year to sustain perennial crops. Results indicate that under a range of plausible future regulations on groundwater pumping ranging from 10% to 50%, water supplies may fail to consistently meet demands, increasing losses by up to 30% of annual revenues. More broadly, the datasets developed in this work will support the development of dynamic models of the integrated water-agriculture system under uncertain climate and regulatory changes to understand the combined impacts of water supply shortages and intensifying irrigation demand.

Water Surplus and Drought Management Update - Conditions as of 11/29/2022

Metropolitan Water District of Southern California (MWD) | December 13th, 2022

Water Use Across the Conterminous United States, Water Years 2010–20, Chapter D of U.S. Geological Survey Integrated Water Availability Assessment—2010–20

U.S. Geological Survey (USGS) | January 15th, 2025

Key Points An estimated average of 223,594 million gallons per day (Mgal/d; 26,179 million cubic meters per month [Mm3/mo]) were withdrawn from freshwater sources fo

Key Points An estimated average of 223,594 million gallons per day (Mgal/d; 26,179 million cubic meters per month [Mm3/mo]) were withdrawn from freshwater sources for human use for crop irrigation, public supply, and thermoelectric power across the conterminous United States (CONUS) during water years 2010–20. Including saline water, withdrawals were 244,817 Mgal/d (28,677 Mm3/mo). Average withdrawals and consumptive use (1) for CONUS crop irrigation during water years 2010–20 were 105,497 and 75,698 Mgal/d, respectively; (2) for public supply were 35,440 and 4,219 Mgal/d, respectively; and (3) for thermoelectric power from fresh water were 82,656 Mgal/d and 2,904 Mgal/d, respectively. Across the CONUS, the source of water—whether groundwater, surface water, public supply, reclaimed wastewater, or a combination thereof—typically depends on the availability of these sources and on the category of use. The water-use categories of industrial, self-supplied domestic, mining, livestock, and aquaculture together accounted for 10 percent of water withdrawals in the United States in 2015. Although a small proportion nationally, these water-use categories can be locally important. Companion chapters: U.S. Geological Survey Integrated Water Availability Assessment—2010–20, Chapter A Water Supply in the Conterminous United States, Alaska, Hawaii, and Puerto Rico, Water Years 2010–20, Chapter B Status of Water-Quality Conditions in the United States, 2010–20, Chapter C  Climate Change and Future Water Availability in the United States, Chapter E  Integrated Water Availability in the Conterminous United States, 2010–20, Chapter F 

Water Use by Urban Lawns and Trees in Los Angeles

University of California, Los Angeles (UCLA) | July 24th, 2017

Water Use Trends in the United States

Pacific Institute | April 15th, 2015

Total water use in the United States declined markedly in the five-year period ending in 2010, according to data released from the United States Geological Survey (USGS).

Total water use in the United States declined markedly in the five-year period ending in 2010, according to data released from the United States Geological Survey (USGS). Total water use in the U.S. is now lower than it was in 1970, despite continued population and economic growth. The Pacific Institute analyzes and explains the factors contributing to this positive news, while including a cautionary note, in a new report released today. The Pacific Institute, an internationally-renowned independent think tank focused on water issues, reviewed the USGS’ most recent data collection, along with historical, national water use data. Remarkably, water use in 2010 was down in all sectors – agriculture, municipal and industrial, and thermoelectric power. The Pacific Institute’s new report shows that reductions in water use for thermoelectric power generation – the single largest use of water in the U.S. – accounted for nearly two-thirds of the reduction in water use between 2005 and 2010. This represents an important reversal of a 25-year trend of increasing water use to produce energy. In addition, water use for agricultural irrigation was at its lowest level in more than 40 years, even while the number of acres irrigated increased. The report shows that, from 2005 – 2010, per capita water use in the United States declined 17% to 1,200 gallons per person per day, levels not seen since the 1940s and the single largest decline in any five-year period. Moreover, the economic productivity of water – which measures the dollars of Gross Domestic Product per unit of water used – increased by 20% during that period to an all-time high of $11.49 per 100 gallons, an indication that the U.S. produces far more wealth, with less water than at any time in the past. While these trends reveal overall improvements in the management of our nation’s water , the current pace of its use is still not sustainable. Continued population and economic growth, along with the impacts of climate change, will strain the amount of water available for a thirsty nation. “The data suggest that national water use is moving in the right direction, but this doesn’t mean the work is done or that existing efforts are sufficient,” states lead author Kristina Donnelly. “We must continue to improve water use efficiency in our homes, businesses, and on America’s farms in order to ensure a sustainable water supply for the nation.”

Water-Energy Synergies: Coordinating Efficiency Programs in California

Pacific Institute | September 4th, 2013

All forms of energy – from hydropower to solar panels – use water to extract and process the fuels, construct the processing facilities, or generate the electricity.

All forms of energy – from hydropower to solar panels – use water to extract and process the fuels, construct the processing facilities, or generate the electricity. Likewise, water supply, treatment, use, and disposal use considerable amounts of energy. Coordinating water-energy efficiency efforts provides a significant opportunity to achieve greater savings for both water and energy utilities and for their customers, according to a new study from the Pacific Institute: Water-Energy Synergies: Coordinating Efficiency Programs in California. Recent events have made the connections between water and energy very visible. The Rim Fire has burned large sections of the Tuolumne River watershed and along several miles of the Hetch Hetchy Reservoir, affecting the water and energy supply of San Francisco and other Bay Area communities. Similarly in Southern California, the recent closure of the San Onofre Nuclear Generating Station has raised concerns about meeting regional energy needs, particularly during the hot summer months, when electricity and water demand are especially high. But while these events demonstrate some of the challenges associated with the water-energy connection, they also highlight some of the opportunities: namely that saving water saves energy – and using less energy in turn saves even more water – reducing our vulnerability to both water and energy constraints. To better understand the barriers to coordinating water and energy efficiency programs, the Pacific Institute interviewed and surveyed California water and energy managers. The managers reported the most significant barriers were associated with funding, limited staff time, uncertainty about how to allocate costs and benefits among project partners, and water-related pricing policies, as well as an absence of established relationships between potential water and energy partners. “We examine the barriers to coordinated water and energy efficiency programs and discuss, through case studies, ways that several California utilities have been able to overcome these barriers,” said Heather Cooley, co-director of the Pacific Institute Water Program. “Coordinating programs can be an important tool to meet efficiency goals, allowing the state to meet critical policy objectives and saving Californians’ money.”

Where We Agree: Building Consensus on Solutions to California’s Urban Water Challenges

Pacific Institute | March 9th, 2016

California has a long list of unresolved and difficult water challenges, made more urgent by the severe drought that is gripping the state. As the state’s population co

California has a long list of unresolved and difficult water challenges, made more urgent by the severe drought that is gripping the state. As the state’s population continues to grow and climate changes become increasingly apparent, the pressures to identify and implement solutions to these critical challenges have only intensified. Recognizing an urgent need for serious changes in the way water is managed and used in the state, a broad array of stakeholders saw an opportunity to move beyond the traditional rancor and conflict by coming together to identify pragmatic and achievable solutions to urban water challenges. During 2015, the Pacific Institute, in partnership with the California-Nevada Section of the American Water Works Association, UC Berkeley Water Center, and UC Davis Extension’s Collaboration Center, coordinated a series of in-depth Where We Agree meetings. This unique effort provided participants opportunities to set aside differences and explore water technologies and policies that would have broad support. Together, they generated a set of practical recommendations for policymakers, municipal water managers, businesses, and community groups. “It’s time to put disagreements aside and concentrate on implementing solutions that we know work and launching innovative approaches to managing the state’s water resources,” said Pacific Institute Water Program Director Heather Cooley. “I am delighted with the progress this group made to create and advance a wide range of positive, on-the-ground solutions to California’s water crisis.”