To Quench a Thirst

San Diego County Water Authority (SDCWA) | October 10th, 2023

The story has three parts: the first tells how the early residents lived with their local resources; the second, which begins in the 1920s, tells the story of how the [Sa

The story has three parts: the first tells how the early residents lived with their local resources; the second, which begins in the 1920s, tells the story of how the [San Diego County] region has become heavily dependent on imported water, and the third is just starting. It is the part of the story about how the region will learn to thrive in a changing climate that has turned 20th century norms for water and weather upside down.

Turf Replacement Program Impacts on Households and Ratepayers: An Analysis for the City of Los Angeles

University of California, Los Angeles (UCLA) | September 30th, 2016

Ongoing severe drought and climate change continue to strain the Los Angeles region’s water supply and have forced the City to institute water savings goals (Garcetti,

Ongoing severe drought and climate change continue to strain the Los Angeles region’s water supply and have forced the City to institute water savings goals (Garcetti, 2014). Turf replacement programs, which aim to encourage residents to replace their lawn with less water intensive landscaping, may offer benefits as part of a larger package of conservation measures. More than half of residential water use is allocated for outdoor watering (approximately 54%) (Firestone, 2015). Outdoor water use is typically considered discretionary while indoor water use is generally considered essential, making outdoor water use a good target for conservation efforts. In order to encourage turf replacement, the city launched a turf replacement program in 2009. Commercial and residential customers can receive a rebate from the utility when they replace their lawns with less water intensive landscaping. Currently, the city is offering a rebate of $1.75 per sq. ft. up to 1,500 sq. ft. This report seeks to answer two questions regarding the turf replacement program. First, under what conditions does participation in the turf replacement program provide financial benefits to households? Second, is the turf replacement program a reasonably cost effective investment for utilities and ratepayers?

Unintended consequences of water conservation on the use of treated municipal wastewater

Nature Portfolio (Springer Nature) | May 11th, 2020

Municipal water managers are intensifying efforts to reduce urban water use and increase the reliability of local water supplies to combat rising water scarcity and droug

Municipal water managers are intensifying efforts to reduce urban water use and increase the reliability of local water supplies to combat rising water scarcity and drought. Incentivizing increases in water-use efficiency and mandating conservation are two strategies to rein in demand. Concurrently, local water supplies are being augmented through investments in reclaiming and treating municipal wastewater. Although reducing urban water consumption is necessary to deal with population growth and a more variable climate, it does come at a cost. In particular, cutting back on indoor water consumption impacts the generation and quality of wastewater, which can have widespread and underappreciated consequences on human society and the environment. Here, to quantify these impacts, we tracked monthly effluent flow, salinity levels and the properties of 34 wastewater treatment plants throughout Southern California from 2013 to 2017—a period that included extreme drought and abundant precipitation. Our analysis demonstrates that conservation measures significantly reduced effluent flow and increased effluent salinity (P value ≤ 0.05). Our findings further highlight the need for policymakers to recognize the interdependencies and complexities within a water system.

Untapped Potential: An Assessment of Urban Stormwater Runoff Potential in the United States

Pacific Institute | February 29th, 2024

In this assessment, we quantify the volumetric potential for stormwater runoff in US Census Urban Areas across the entire United States. This assessment finds that the av

In this assessment, we quantify the volumetric potential for stormwater runoff in US Census Urban Areas across the entire United States. This assessment finds that the average annual volumetric potential for urban stormwater runoff is 59.5 million acre-feet per year (AFY), or 53,100 million gallons per day (MGD). This volume is equivalent to 93% of the water withdrawals for municipal and industrial uses in 2015, though not all of this runoff is necessarily feasible or desirable to capture. We estimate that 37% of this national volume (21.9 million AFY) is generated just in coastal areas, which presents an opportunity for increased stormwater capture in areas that are less likely to face challenges related to adverse impacts on downstream water rights holders.

Urban and Agricultural Water Use in California, 1960–2015

Pacific Institute | June 22nd, 2020

Water is the lifeblood of California. It provides for the household needs of 40 million people. It generates electricity and cools power plants. It supports one of the mo

Water is the lifeblood of California. It provides for the household needs of 40 million people. It generates electricity and cools power plants. It supports one of the most productive agricultural regions in the world and various commercial and industrial activities, ultimately fueling the fifth largest economy in the world. Water is also critical to the health and viability of the state’s diverse aquatic and terrestrial ecosystems. This paper examines statewide urban and agricultural water-use trends from 1960 to 2015 using data from the California Department of Water Resources (DWR). We find that California has experienced a dramatic decoupling between water use and growth. Since 1967, California’s population has doubled, and its economic output has increased by a factor of five. Yet statewide water use increased by only 20 percent over this period due to improvements in urban and agricultural efficiency, as well as a shift to higher-value crops and less water-intensive commercial and industrial activities.  Despite positive signs, water use in California remains high. Across the state, rivers and streams are under stress from overuse, and groundwater is over-tapped. Climate change and continued growth are increasing pressure on the state’s water resources, including on water supply, demand, and quality. To address these challenges, we must continue and even expand efforts to improve the water-use efficiency of our homes, businesses, industries, and farms. Moreover, we urge the state to improve data collection and online systems to make data more easily, quickly, and readily available.

Urban Ecological Planning Guide for Santa Clara Valley

San Francisco Estuary Institute (SFEI) | June 20th, 2019

Like most cities, the urbanized region of Santa Clara Valley is a challenging place for plants and animals to make a home. Largely covered with pavement, crisscrossed by

Like most cities, the urbanized region of Santa Clara Valley is a challenging place for plants and animals to make a home. Largely covered with pavement, crisscrossed by major freeways, and fragmented by a variety of land uses, the urban landscape creates barriers to the movement of wildlife and hostile environments for plants. While a small set of species tolerant of cities (such as pigeons and raccoons) can tolerate these difficult conditions, our cities have the potential to support much greater biodiversity. Urban greening projects are already occurring piecemeal across urban landscapes. Harnessing this momentum can help these efforts build greater benefits for biodiversity and for people.  Urban greening projects may take many forms, such as rain gardens beside roadways; bike trails with vegetated medians; planted and expanded riparian vegetation along stream corridors; and landscaping in corporate campuses, municipal parks and private gardens. While often driven by a narrow set of goals such as stormwater capture, public safety, shade, or beautification, these green spaces can be designed and coordinated to support enhanced biodiversity as well. Rain gardens can support native wetland plants, bike trail medians can support ribbons of wildflowers for native insects, street trees can shade pedestrians and provide acorns for birds and squirrels, and stream revegetation or daylighting projects can provide a reflective place for people and strengthen corridors for regional species movement. While each of these types of projects provides benefits, strategically designing these features to reflect ecologically-minded planning, and where possible, coordinating across the landscape, can provide value for humans and nature alike.  This document provides some of the scientific foundation needed to guide planning for urban biodiversity in the Santa Clara Valley region, grounded in an understanding of landscape history, urban ecology and local setting. It can be used to envision the ecological potential for individual urban greening projects, and to guide their siting, design and implementation. It also can be used to guide coordination of projects across the landscape, with the cooperation of a group of stakeholders (such as multiple agencies, cities and counties). Users of this report may include a wide range of entities, such as local nonprofits, public agencies, city planners, and applicants to the Open Space Authority’s Urban Open Space Grant Program.  This document is not intended to inform all aspects of site-specific planning. Much guidance on these topics is already available, and we reference some of those resources here. Rather, it is intended as a companion to existing materials, to inform a broader vision of how such site-scale projects can fit into the larger fabric of the Santa Clara Valley landscape. This document also recommends appropriate habitats and lists of their associated plants for the region, as well as general guidance on practical considerations related to project implementation. 

Urban Water Conservation and Efficiency Potential in California

Pacific Institute | June 10th, 2014

Improving urban water-use efficiency is a key solution to California’s short-term and long-term water challenges: from drought to unsustainable groundwater use to growi

Improving urban water-use efficiency is a key solution to California’s short-term and long-term water challenges: from drought to unsustainable groundwater use to growing tensions over limited supplies. Reducing unnecessary water withdrawals leaves more water in reservoirs and aquifers for future use and has tangible benefits to fish and other wildlife in our rivers and estuaries. In addition, improving water-use efficiency and reducing waste can save energy, lower water and wastewater treatment costs, and eliminate the need for costly new infrastructure.

Urban Water Conservation in the Sacramento, California Region During the 2014-2016 Drought

ProQuest Dissertations Publishing | December 30th, 2019

Urban Water Management Planning Guidebook for Urban Water Suppliers (2015)

California Department of Water Resources (DWR) | March 3rd, 2016

The Guidebook for Urban Water Suppliers (Guidebook) has been developed by Department of Water Resources to assist urban water suppliers in preparing 2015 Urban Water Mana

The Guidebook for Urban Water Suppliers (Guidebook) has been developed by Department of Water Resources to assist urban water suppliers in preparing 2015 Urban Water Management Plans (UWMPs or Plans). This guidance is intended to ensure the Plans will address the requirements of the California Water Code (CWC), provide useful information to the public about water suppliers and their water management programs, and provide a framework for water planning to minimize the negative effects of potential water shortages. Water suppliers need not limit themselves to the requirements and recommendations found in the Guidebook. Suppliers may include any additional information that will assist in providing a full description of their water resources and water management.

Urban Water Revolution: Sustainable Water Futures for California Cities

American Society of Civil Engineers (ASCE) | July 15th, 2020

California has consistently altered natural water resources to provide water for its growing population and to support the fifth largest economy in the world. However, th

California has consistently altered natural water resources to provide water for its growing population and to support the fifth largest economy in the world. However, the old ways of coping with the California’s urban water needs—overdraft of groundwater, stream depletion, and greater imports—will no longer meet the demands of the 21st century. We examine California’s water history and present several promising solutions to the challenge of urban water security: a combination of conservation and efficiency, desalination, stormwater capture, water re-use, and water banking. These options for urban water, including direct potable reuse, will help dry cities in California and elsewhere achieve more sustainable and diversified water supply portfolios. Pilot and demonstration-scale projects, along with innovations in systems management and new regulations, point the way toward more resilient water supplies for dry cities. Movement toward regional collaboration, implementation of new technologies, and new regulatory regimes are helping to realize a one-water vision. Different cities will develop their own water supply portfolio options appropriate for their geography, values, and urban form on a path toward meeting the urban water challenges of this century.