Freshwater Scarcity

Annual Review of Environment and Resources (Annual Reviews) | October 24th, 2021

The availability and use of fresh water are critical for human health and for economic and ecosystem stability. But the growing mismatch between human demands and natur

The availability and use of fresh water are critical for human health and for economic and ecosystem stability. But the growing mismatch between human demands and natural freshwater availability is contributing to water scarcity, affecting industrial and agricultural production and a wide range of social, economic, and political problems, including poverty, deterioration of ecosystem health, and violent conflicts. Understanding and addressing different forms of water scarcity are vital for moving toward more sustainable management and use of fresh water. We provide here a review of concepts and definitions of water scarcity, metrics and indicators used to evaluate scarcity together with strategies for addressing and reducing the adverse consequences of water scarcity, including the development of alternative sources of water, improvements in water-use efficiency, and changes in systems of water management and planning.

From wastewater treatment plants to decentralized resource factories

Nature Portfolio (Springer Nature) | June 10th, 2024

Funding Opportunity for Voluntary Participation in the Lower Colorado Conservation and Efficiency Program

U.S. Bureau of Reclamation (USBR) | October 12th, 2022

Future land-use related water demand in California

Environmental Research Letters (IOP) | May 18th, 2019

Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use r

Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use restrictions. Increases in population and land use in coming decades will place additional pressure on already limited available water supplies. We used a state-and-transition simulation model to project future changes in developed (municipal and industrial) and agricultural land use to estimate associated water use demand from 2012 to 2062. Under current efficiency rates, total water use was projected to increase 1.8 billion cubic meters (+4.1%) driven primarily by urbanization and shifts to more water intensive crops. Only if currently mandated 25% reductions in municipal water use are continuously implemented would water demand in 2062 balance to water use levels in 2012. This is the first modeling effort of its kind to examine regional land-use related water demand incorporating historical trends of both developed and agricultural land uses.

GreenPlan-IT Tracker

San Francisco Estuary Institute (SFEI) | June 14th, 2018

This technical memo describes the purpose, functions, and structure associated with the newest addition to the GreenPlan-IT Toolset, the GreenPlan-IT Tracker. It also sh

This technical memo describes the purpose, functions, and structure associated with the newest addition to the GreenPlan-IT Toolset, the GreenPlan-IT Tracker. It also shares the opportunities for further enhancement and how the tool can operate in concert with existing resources. Furthermore, this memo describes a licensing plan that would permit municipalities to use the tool in an ongoing way that scales to their needs. The memo concludes with a provisional roadmap for the development of future features and technical details describing the tool’s platform and data structures. About the GreenPlan-IT Toolkit Municipalities across the state and beyond are carefully planning and implementing green infrastructure in their developed landscape to restore key aspects of the natural water cycle. Green infrastructure helps to achieve stormwater attenuation and contaminant filtration by increasing the pervious surfaces in often sophisticated ways. Additionally, green infrastructure features, as city dwellers have come to realize, demonstrate multiple benefits in addition to improving surface porosity, such as peak, volume, and load reductions, urban heat island mitigation, traffic calming, carbon sequestration, wildlife habitat, natural aesthetics, and others. The benefits are substantial, but so are the potential costs. GreenPlan-IT helps planners to make smart decisions in the types and locations of green infrastructure, minimizing effort and cost while maximizing the effectiveness of the public and private investments. GreenPlan-IT modules are focused on green infrastructure planning and assessment, including the Site Locator Tool, Modeler, and Optimizer tools. Together the modular toolkit can be used to take a city from a position of not knowing where to consider GI placement (a daunting position given the MRP C3 and C11/12 requirements), to a plan that includes a list and map of feasible locations and a map of baseline flow and pollutant load conditions, and a selected optimal set of placement locations for achieving flow and load reductions at minimal cost. Now, with the advent of the GreenPlan-IT Tracker, there is also a web based tracker for quantifying and communicating the locations, types, and treatment areas of GI installations (the outputs of all the planning efforts) and quantifying the peak flows, volumes, and loads reduced (the outcomes of all the implementation and cost expenditure that the community is asking for).

Groundwater and Urban Growth in the San Joaquin Valley

Public Policy Institute of California (PPIC) | September 20th, 2021

The San Joaquin Valley is ground zero for the Sustainable Groundwater Management Act (SGMA). It has the largest groundwater deficit in California and faces some of the

The San Joaquin Valley is ground zero for the Sustainable Groundwater Management Act (SGMA). It has the largest groundwater deficit in California and faces some of the worst impacts from overdraft, including land subsidence and drying wells. SGMA will help the region address these issues—while also building its climate resilience. But this will require hard work, not only by farmers—the largest groundwater users—but also by the valley’s urban water utilities, which serve a growing population while relying mostly on groundwater. As the valley confronts limits on groundwater pumping, urban utilities, local land use authorities, other water users, and state agencies must all engage to ensure a smooth transition for the region’s residents.

Guide for Developing Onsite Water Systems to Support Regional Water Resilience

Pacific Institute | January 26th, 2023

Across the United States, urban communities face growing water challenges, from water scarcity to flooding, pollution, aging water infrastructure, and more. These challen

Across the United States, urban communities face growing water challenges, from water scarcity to flooding, pollution, aging water infrastructure, and more. These challenges present risks, but also an opportunity to rethink how we manage water, including adopting circular approaches in new buildings that reduce their water footprint and improve urban water resilience. Onsite water systems, for example, collect, treat, and reuse water from onsite sources, including wastewater, rainwater, and stormwater, for non-potable water uses like toilet flushing, outdoor irrigation, and cooling. Onsite water systems have the potential to provide multiple benefits for a site, water and wastewater systems, ecosystems, and communities. They can, for example, help companies mitigate water- related risks, like water shortages that threaten to disrupt business operations, and support corporate water stewardship goals. For communities, onsite water systems can enhance water supply reliability, improve water quality, reduce localized flooding, and increase urban green space. The realization and magnitude of benefits will vary with the type of system, scale of adoption, and other context-specific factors. This guide helps site developers consider how onsite water systems can be planned, designed, and operated to provide multiple benefits, and contribute to planning and designing onsite water systems that advance water resilience, support equity, support the environment, and protect public health at the site, water system, and community scales. For each of these outcomes, the guide provides sample questions to consider, stakeholders to engage, resources to examine, and analyses to perform.

Guidebook to Assist Urban Water Suppliers to Prepare a 2010 Urban Water Management Plan

California Department of Water Resources (DWR) | March 17th, 2011

Guidebook to Assist Urban Water Suppliers to Prepare a 2010 Urban Water Management Plan (Guidebook) has been developed by the California Department of Water Resources (

Guidebook to Assist Urban Water Suppliers to Prepare a 2010 Urban Water Management Plan (Guidebook) has been developed by the California Department of Water Resources (DWR) to assist urban water suppliers in complying with requirements of the Urban Water Management Planning Act (the UWMP Act) and the Water Conservation Bill of 2009. It is meant to help suppliers better understand UWMP Act requirements, but water suppliers are solely responsible for ensuring they’ve complied with the requirements of the UWMP Act or applicable laws. For the purposes of this Guidebook and the UWMP Act, urban water suppliers with 3,000 or more service connections or supplying 3,000 or more acre-feet of water per year are to prepare a UWMP every five years.

Hidden Oasis: Water Conservation and Efficiency in Las Vegas

Pacific Institute | November 20th, 2007

Two of the West’s preeminent water organizations report Las Vegas Valley is sitting on an oasis of water and money savings. In their new report, the Pacific Institute a

Two of the West’s preeminent water organizations report Las Vegas Valley is sitting on an oasis of water and money savings. In their new report, the Pacific Institute and Western Resource Advocates find up to 40% of water could be saved in some sectors through improvements to indoor and outdoor water efficiency. They also found that through improving indoor water efficiency in particular, Las Vegas residents and businesses can cut water-related energy use and greenhouse gases. These findings are contained in Hidden Oasis: Water Conservation and Efficiency in Las Vegas available for download below. “Ninety percent of Las Vegas’ water efficiency money is spent on one program—turf removal. This program is important, but participation has waned and it is far from the only tool at their disposal,” said Heather Cooley, report co-author and Pacific Institute Senior Associate. “Las Vegas should capitalize on strategies that other Western cities have proven to be effective.” Hidden Oasis reveals that the Southern Nevada Water Authority, which provides water to Las Vegas and surrounding communities, can tap a number of tested, cost-effective efficiency measures to cut current water waste by up to 86,000 acre-feet. Single-family homes in Las Vegas use 100 gallons of water outside, per person, per day—almost entirely for landscaping. This use is substantially higher than in Los Angeles, Tucson, or Albuquerque. Reducing Las Vegas’ outdoor water use to more reasonable levels could cut Nevada’s total Colorado River withdrawals by 10 percent. Researchers found that by improving and expanding existing programs, and adding programs proven elsewhere in the West, the SNWA can cut Las Vegas homeowners’ indoor water waste by 40% and hotel and casino water waste by 30%. These indoor efficiency gains come from upgrading fixtures and appliances, not changing behavior. Improving total water efficiency not only saves significant water and energy expenses, it also better insulates the region from drought. “Improving indoor and outdoor water efficiency makes Las Vegas less vulnerable to current and future droughts,” said Taryn Hutchins-Cabibi, report coauthor and Water Policy Analyst at WRA. “Given the scarcity of fresh water, rising energy prices, and the looming threat of climate change, Las Vegas’ water customers need the SNWA’s help to curb unnecessary water waste and save money.”

How much potable water is saved by wastewater recycling? Quasi-experimental evidence from California

Resources, Conservation & Recycling (Elsevier) | October 6th, 2021

Recently, California has made large investments in wastewater recycling to replace applications that use potable water. It may be expected that the use of recycled water

Recently, California has made large investments in wastewater recycling to replace applications that use potable water. It may be expected that the use of recycled water reduces potable water use, but such an equivalency is not assured. The addition of recycled water infrastructure in a large Californian water district creates a natural experiment where this work tests how recycled water usage affects primary potable water. This is done using econometric methods for causal inference in an observational setting that mirror a randomized control trial (RCT). From 2001 to 2014, a number of public parks were given recycled water infrastructure, while others in those regions remained exclusively on potable supply. A two-way fixed effects regression is used to produce a difference-in-differences estimate of the average treatment effect of recycled water on total and potable water usage. The results indicate that potable water usage is reduced significantly when a park is connected to the recycled water supply. The estimated rate of displacement in the study period is 81.7%, meaning each unit of recycled water use avoided 0.817 units of potable water usage, which implies the connection of parks to recycled water supply increases total water use. The analysis provides, to the best of our knowledge, the first empirical estimate of the water savings claimed by urban water recycling programs, and the first empirical estimate of displacement using quasi-experimental methods. The methodology can be utilized to evaluate the effectiveness of recycling programs around the world.