Colorado River

Water from the Colorado River

Metropolitan Water District of Southern California (MWD) | July 1st, 1931

It is the purpose of this booklet to outline the Boulder Canyon Dam project on the Colorado River and the Metropolitan Aqueduct. Furthermore, it seems pertinent to indica

It is the purpose of this booklet to outline the Boulder Canyon Dam project on the Colorado River and the Metropolitan Aqueduct. Furthermore, it seems pertinent to indicate the extent of the population, industrial and agricultural resources of the Metropolitan area, which stand behind and urgently require Colorado River development.

Water Quality Control Plan for the Colorado River region (CA)

Colorado River Regional Water Quality Control Board (CRRWQCB) | August 16th, 2017

This Water Quality Control Plan (herein referred to as the Basin Plan) for the Colorado River Basin Region was prepared by the California Regional Water Quality Control B

This Water Quality Control Plan (herein referred to as the Basin Plan) for the Colorado River Basin Region was prepared by the California Regional Water Quality Control Board, Colorado River Basin Region, in accordance with criteria contained in the California Porter-Cologne Water Quality Control Act, the Federal Clean Water Act, and other pertinent state and federal rules and regulations. The intent of the Basin Plan is to provide definitive guidelines, and give direction to the full scope of Regional Board activities that serve to optimize the beneficial uses of the state waters within the Colorado River Basin Region of California by preserving and protecting the quality of these waters. Water uses and water benefits vary. Water quality is an important factor in determining use and benefit. For example, drinking water has to be of higher quality than the water used to irrigate pastures. Both of these are beneficial water uses, but the quality requirements for irrigation water are different from those for drinking water. The Basin Plan recognizes the variations of water quality and water uses. This Basin Plan lists and defines the various beneficial water uses  (Chapter 2). It describes the water quality which must be maintained to support such uses (Water Quality Objectives, Chapter 3). The section on implementation (Chapter 4) describes the programs, projects and other actions which are necessary to achieve the standards established in this Plan. Plans, Policies and Issues (Chapter 5), summarize the various plans and policies which protect water quality. This chapter also describes water quality issues which require special attention. Surveillance and Monitoring (Chapter 6), describes activities within the Colorado River Basin Region which are related to surveillance, monitoring, assessment, lab support, quality assurance and quality control. The Regional Board implements the Basin Plan by issuing and enforcing waste discharge requirements to persons; which can include individuals, communities, or businesses whose waste discharges may affect water quality. These requirements can be either state Waste Discharge Requirements for discharge to land, or federally delegated National Pollutant Discharge Elimination System permits for discharges to surface water. Dischargers are required to meet water quality objectives and thus protect beneficial uses. This Basin Plan also encourages water users to improve the quality of their water supplies, particularly where the wastewater they discharge is likely to be reused. Public works and other projects, which can affect water quality, are reviewed and their impacts are identified. Proposals, which implement or help achieve the goals of the Basin Plan, are supported. This Basin Plan is subject to review by the State Water Resources Control Board (State Board) and the United States Environmental Protection Agency (USEPA). The Basin Plan is, in itself, not a final statement on regional water quality planning, but is subject to continuous review and update as necessary. Updated sections of the plan may appear as periodic amendments, which are also subject to approval by the State Board and USEPA.

Water quality for agriculture

Food and Agriculture Organization of the United Nations (FAO) | July 15th, 1985

Water Quality in Basin-Fill Aquifers of the Southwestern United States: Arizona, California, Colorado, Nevada, New Mexico, and Utah, 1993–2009

U.S. Geological Survey (USGS) | July 15th, 2014

Water Quality in California

Public Policy Institute of California (PPIC) | February 23rd, 2026

Water Quality of Groundwater Used for Public Supply in Principal Aquifers of the Western United States

U.S. Geological Survey (USGS) | September 8th, 2020

Water Right Exactions

Social Science Research Network (SSRN) | May 15th, 2023

Water shortages worsened by reservoir effects

Nature Portfolio (Springer Nature) | November 13th, 2018

The expansion of reservoirs to cope with droughts and water shortages is hotly debated in many places around the world. We argue that there are two counterintuiti

The expansion of reservoirs to cope with droughts and water shortages is hotly debated in many places around the world. We argue that there are two counterintuitive dynamics that should be considered in this debate: supply–demand cycles and reservoir effects. Supply–demand cycles describe instances where increasing water supply enables higher water demand, which can quickly offset the initial benefits of reservoirs. Reservoir effects refer to cases where over-reliance on reservoirs increases vulnerability, and therefore increases the potential damage caused by droughts. Here we illustrate these counterintuitive dynamics with global and local examples, and discuss policy and research implications.

Water Supply Conditions in Southern California during 1958-1959, Volume II, Water Level Data, Central Coastal and Los Angeles Regions

California Department of Water Resources (DWR) | May 1st, 1961

Water to Supply the Land: Irrigated Agriculture in the Colorado River Basin

Pacific Institute | May 9th, 2013

The Colorado River, recently named America’s most endangered river, supports millions of people in the American Southwest and northwest Mexico and helps irrigate millio

The Colorado River, recently named America’s most endangered river, supports millions of people in the American Southwest and northwest Mexico and helps irrigate millions of acres of land. Yet demands on the river already exceed the river’s average supply, a situation that is projected to get worse in coming years as climate change reduces runoff at the same time that fast-growing southwest cities demand more water. Irrigated agriculture currently consumes more than 70% of the water supply within the Colorado River basin, making it critical for more efficient water use. For the first time, new research from the Pacific Institute describes the extent of irrigated agriculture throughout the seven Colorado River basin states and two additional states in Mexico, the types of crops grown, and the amount of water used to grow these crops. In addition, the new report – Water to Supply the Land: Irrigated Agriculture in the Colorado River Basin – compares several agricultural management scenarios and the potential water savings and costs associated with each. Importantly, none of the scenarios remove agricultural land from production. More than 90% of pasture and cropland in the 256,000-square-mile Colorado River Basin requires irrigation, with about 60% of the irrigated acreage devoted to pasture, alfalfa, and other forage crops used to feed cattle and horses. These forage crops consume about 5 million acre-feet per year, equivalent to a third of the river’s annual flow. Employing innovative irrigation techniques more strategically and in more places – techniques that many farmers are already using – can help ensure agriculture in the basin states continues in the face of rising demand and climate change’s projected impact on supply. Modeling a series of agricultural water management conservation strategies – including regulated deficit irrigation, crop shifting, and advanced irrigation technologies – the Pacific Institute compared potential water savings and costs associated with individual scenarios. The analysis shows considerable water savings are possible. For example, almost a million acre-feet of water may be generated by irrigating alfalfa less often (a practice known as “regulated deficit irrigation”) throughout the basin in the U.S., at an estimated base cost of approximately $81 per acre-foot. Other scenarios, such as shifting to less water-intensive crops, also yield impressive water savings with relatively low costs and without reducing the total amount of irrigated acreage in the basin. For example, replacing about 10% of the basin’s irrigated alfalfa acreage with cotton and wheat could save about 250,000 acre-feet of consumptive water use each year, with estimated base costs of less than $40 per acre-foot. Total reductions in water withdrawals and applied water would be even greater.