The cost of alternative urban water supply and efficiency options in California

Environmental Research Communications (IOP) | May 28th, 2019

Urban communities, farms, businesses, and natural ecosystems depend upon adequate, reliable, and affordable supplies of clean water. As populations and economies

Urban communities, farms, businesses, and natural ecosystems depend upon adequate, reliable, and affordable supplies of clean water. As populations and economies grow and as climatic changes alter both water supply and demand, traditional options for meeting freshwater needs are becoming less available, reliable, and effective. As we approach peak water constraints on traditional water supplies, more efforts needed to reduce water demands through a wide range of conservation and efficiency technologies and policies, and to develop alternative, non-traditional water sources. A key factor in the adoption of these strategies is their economic feasibility; yet, only limited and often confusing data are available on their relative costs. To fill this gap, this analysis evaluates the costs of four groups of alternatives for urban supply and demand based on data and analysis in the California context: stormwater capture; water recycling and reuse; brackish and seawater desalination; and a range of water conservation and efficiency measures. We also describe some important co-benefits or avoided costs, such as reducing water withdrawals from surface water bodies or polluted runoff in coastal waterways. While difficult to quantify, such benefits are economically relevant, and we highlight areas where further research and analysis are needed to improve estimates presented here. All of the water- use efficiency options are far less costly than traditional or alternative supply systems with the exception of some of the most expensive landscape water reduction options. The water treatment and reuse systems and the urban stormwater capture projects are more costly per unit of water produced but still less expensive than seawater desalination—the most expensive option evaluated.

The Cost of Alternative Water Supply and Efficiency Options in California

Pacific Institute | October 13th, 2016

The Cost of Alternative Water Supply and Efficiency Options in California is the first comprehensive analysis to examine the cost of various strategies throughout the sta

The Cost of Alternative Water Supply and Efficiency Options in California is the first comprehensive analysis to examine the cost of various strategies throughout the state to augment local water supplies and reduce water demand in urban areas. The study uses methods developed in the field of energy economics to determine the “levelized” costs of each supply and demand management option. The study finds that the cost of new supplies in California is highly varied. Large stormwater capture projects are among the least expensive of the water supplies examined, with a median cost of about $590 per acre-foot. By contrast, seawater desalination, with a median cost of $2,100 per acre-foot for large projects and $2,800 per acre-foot for smaller projects, is among the most expensive water supply option. Brackish water desalination is much less expensive due to lower energy and treatment costs. Generally, the cost of recycled water is in between that of stormwater capture and seawater desalination. Non-potable reuse – which treats water for irrigation and other non-drinking purposes – is typically less expensive than indirect potable reuse due to the lower treatment requirements; however, the cost of building or expanding a separate “purple pipe” distribution system to deliver non-potable water may be such that indirect potable reuse could be more cost effective. Nonetheless, the study finds that urban water conservation and efficiency are the most cost-effective ways to meet current and future water needs. Indeed, many residential and non-residential measures have a “negative cost,” which means that they save the customer more money over their lifetime than they cost to implement.

The Cost of Regulating Active Landfills for Water Quality

California State Water Resources Control Board (SWRCB) | January 3rd, 2016

This report to the legislature was prepared pursuant to Chapter 718, Statutes of 2010 (SB 855, Committee on Budget and Fiscal Review), which requires the State Water Reso

This report to the legislature was prepared pursuant to Chapter 718, Statutes of 2010 (SB 855, Committee on Budget and Fiscal Review), which requires the State Water Resources Control Board (State Water Board) to submit to the budget committees in each house of the legislature a report on the costs of regulating water quality at active landfills. The State Water Board and Regional Water Quality Control Boards (Regional Boards, collectively, the Water Boards) analyzed the cost of resources required to implement State and Federal statutes, regulations, and policies at these facilities. This report provides an overview of the Water Boards’ Land Disposal Program, followed by a cost analysis. The Water Boards’ Land Disposal Program provides regulatory oversight to 439 active landfills and 235 other waste management facilities in the State. Active landfills are all landfills that still pose a threat to the environment, even if they have stopped accepting waste. Active landfills are classified as operating or non-operating, with non-operating landfills including proposed, closing, and closed landfills. There are an estimated 1600 legacy landfills that were not included in the cost analysis for this report. Legacy landfills are waste management units that were closed, abandoned, or inactive prior to the adoption of revised State Water Board regulations in November 1984. In response to the legislative requirements, the results of this analysis show the cost of regulating the 439 active landfills to be approximately $18.1 million. The Land Disposal Program also regulates other waste management facilities as an integral part of the program, and tracks these facilities along with active landfills. Based on this analysis, the cost of regulating the 235 other waste management facilities is approximately $7.6 million. In total, implementation of the Land Disposal Program would cost approximately $25.7 million (not including legacy landfills). In Fiscal Year 2011-2012, the total expenditures incurred by the Land Disposal Program were approximately $10.6 million. As this presents an approximately $15.2 million shortfall in funding, the program prioritizes work based on threat to water quality, complexity, and level of activity at the facility. Working within existing resource constraints, the Land Disposal Program is currently implementing a series of efficiency measures to improve program effectiveness. A discussion of these efforts concludes this report.

The Cost of Rehabilitating Dams in the U.S.

Association of State Dam Safety Officials (ASDSO) | August 7th, 2025

In 2022, the ASDSO Board of Directors established a task force to review and update the methodology and processes that were developed several years earlier by ASDSO to es

In 2022, the ASDSO Board of Directors established a task force to review and update the methodology and processes that were developed several years earlier by ASDSO to estimate the costs to rehabilitate non-federal dams in the United States (U.S.). This was a one-year project financed by ASDSO. The updated methodology and processes used readily available data to estimate the number of dams in need of rehabilitation based on dam height, age, and Condition Assessment rating. Data from more than 500 dam rehabilitation projects nationwide, ranging from $10,000 to more than $500 million, was used in determining the total amount of funding needed for dam rehabilitation at a national level. The purpose of this report is to inform national and state policy decisions and provide the public and the media with a high-level understanding of the national dam rehabilitation need in terms of estimated costs. The findings and methodologies are not meant to be used to estimate a specific dam rehabilitation cost.

The critical role of humidity in modeling summer electricity demand across the United States

Nature Portfolio (Springer Nature) | April 3rd, 2020

Cooling demand is projected to increase under climate change. However, most of the existing projections are based on rising air temperatures alone, ignoring that

Cooling demand is projected to increase under climate change. However, most of the existing projections are based on rising air temperatures alone, ignoring that rising temperatures are associated with increased humidity; a lethal combination that could significantly increase morbidity and mortality rates during extreme heat events. We bridge this gap by identifying the key measures of heat stress, considering both air temperature and near-surface humidity, in characterizing the climate sensitivity of electricity demand at a national scale. Here we show that in many of the high energy consuming states, such as California and Texas, projections based on air temperature alone underestimates cooling demand by as much as 10–15% under both present and future climate scenarios. Our results establish that air temperature is a necessary but not sufficient variable for adequately characterizing the climate sensitivity of cooling load, and that near-surface humidity plays an equally important role.

The Decline of Striped Bass in the Sacramento-San Joaquin Estuary, California

American Fisheries Society (AFS) | July 1st, 1985

The abundance of young striped bass Morone saxatilis in the Sacramento-San Joaquin Estuary has suffered an unsteady but persistent decline from population levels that wer

The abundance of young striped bass Morone saxatilis in the Sacramento-San Joaquin Estuary has suffered an unsteady but persistent decline from population levels that were high in the middle 1960s. The decline was particularly severe in 1977 and abundance of young striped bass has been low every subsequent year. The adult striped bass population also has fallen during the past 20 years, but the exact period over which the decline occurred and the rate of decline are not clear. The adult population is now about one-quarter of its former size and there is little sign of recovery. We believe the Sacramento-San Joaquin striped bass population and the fishery that it supports are in serious danger. The cause is most likely one or more of four factors. (1) The adult population is now so low that egg production may be inadequate. (2) The plankton food supply of young striped bass in the western Sacramento-San Joaquin Delta and Suisun Bay has been greatly reduced each spring. Diversion of water from the delta for agricultural purposes is a prime suspect for the decrease in food production. (3) Large numbers of young fish are lost by entrainment in water diversions. (4) The population is stressed by toxic substances such as petrochemicals and pesticides. Additional studies are underway to help determine the principal cause(s) of the striped bass decline.

The Definition of Environmental Justice and the Designation of the California Office of Planning and Research as Coordinating Agency for Environmental Justice

State of California | November 18th, 2019

The Delta as Changing Landscapes

University of California, Davis (UC Davis) | July 1st, 2016

What happens at one place in a landscape influences and is influenced by what happens in other places. Consequently, management and restoration that focus on individual p

What happens at one place in a landscape influences and is influenced by what happens in other places. Consequently, management and restoration that focus on individual places may fail to recognize and incorporate interactions across entire landscapes. The science of landscape ecology, which emphasizes the interplay of landscape structure, function, and change at multiple scales, offers a perspective that can integrate the spatial relationships of ecological processes and the functional interconnections of land and water in the Delta. Although the Delta is one of the most studied estuaries in the world, applications of landscape science have been limited. We describe why it is important to incorporate landscape science into management and restoration, emphasizing how Delta landscapes have changed over the past centuries. The land–water linkages of the past have been broken, waterways have been over-connected, and hard boundaries have replaced the gradual and dynamic transitions among landscape patches. The contemporary landscape also has new, novel assemblages of species and stressors that were not there in the past. This historical perspective indicates how knowledge of past landscape functions can contribute to the restoration and management of contemporary landscapes. We illustrate these points with case studies of inundation dynamics and riparian woodlands, and use a third example to describe a landscape approach to restoration. We propose that science that encompasses the multiple, interacting components of functional landscapes in the Delta will foster resilient and enduring restoration and management outcomes that benefit both people and wildlife. We suggest several ways of moving landscape science to the forefront of management and restoration in the Delta.

The Delta on Fast Forward - Thinking Beyond the Next Crisis (Summary for Policymakers of the State of Bay Delta Science 2016)

University of California, Davis (UC Davis) | December 1st, 2016

Delta science needs to push beyond its tendency to focus on short-term policy mandates and near-term crises. Taking a longer, 50- to 100-year viewpoint has been part of v

Delta science needs to push beyond its tendency to focus on short-term policy mandates and near-term crises. Taking a longer, 50- to 100-year viewpoint has been part of various planning exercises including Delta Vision. That kind of long-range thinking now needs to be more strongly incorporated into the whole Delta science and management endeavor. An appreciation of the changes that are coming, particularly those associated with climate change, needs to inform all our research and planning. In the meantime, despite management actions that in some instances appear heroic, native fish continue to decline in the Delta. The food web has changed dramatically, new stressors are added daily to existing ones, and several native species are virtually extinct. While we must continue to try to shore up the delta smelt, for example, it is time for serious debate about more radical alternatives to habitat restoration, including assisted relocation, assisted evolution, even perhaps cryopreservation (freezing of genetic materials). Agency mandates based on the past should not prevent us from taking actions that prepare us for a very different future. The capacity of the Delta to absorb extremes of all kinds is declining. In the future, water managers will have to adjust to reduced and more variable inflows to the Delta and to less predictable sources of water supply. Sustaining a Delta ecosystem hospitable to native species will be much more difficult. In that case, it may become necessary to refocus on managing for novel plant and animal communities that provide desirable ecosystem services. Delaying action until the next crisis is upon us will greatly increase the risk and costs of failure.

The Delta on Fast Forward: Thinking Beyond the Next Crisis

CALFED | September 1st, 2016