Colorado River

Salton Sea Restoration Fund The State Has Not Fully Funded a Restoration Plan and the State’s Future Mitigation Costs Are Uncertain

California State Auditor | November 1st, 2013

The Salton Sea, located in Riverside and Imperial counties in Southern California, is the State’s largest inland lake. The Salton Sea was formed in 1905 when Colorado

The Salton Sea, located in Riverside and Imperial counties in Southern California, is the State’s largest inland lake. The Salton Sea was formed in 1905 when Colorado River floodwater breached an irrigation canal being constructed in the Imperial Valley; it has since been primarily fed by agricultural drain water. According to experts, the Salton Sea serves as an important fishery and wildlife habitat and is a major stopping point for migratory birds along the Pacific flyway. However, beginning in 2003, a series of agreements know collectively as the Quantification Settlement Agreement (QSA), between the State, local water agencies, and other entities have required, among other things, a water transfer that has reduced the amount of water that flows into the Salton Sea (water transfer). To mitigate the effects of the water transfer, the QSA requires one of the local water agencies that is a party to the agreement to provide additional water (mitigation water) to the Salton Sea for 15 years, from 2003 to 2017. Experts anticipate that when the Salton Sea stops receiving this mitigation water, the water transfer will cause profound negative environmental impacts, including the loss of fishery habitat, exposure of soils to wind erosion, and declines in bird species because of the loss of food.

Salton Sea Study Status Report

U.S. Bureau of Reclamation (USBR) | January 9th, 2003

The Salton Sea is located in a closed basin in Riverside and Imperial Counties in southern California, south of Indio and north of El Centro. The Sea is situated

The Salton Sea is located in a closed basin in Riverside and Imperial Counties in southern California, south of Indio and north of El Centro. The Sea is situated in a closed basin, more than 200 feet below sea level and has no natural outlet. Although lakes have existed in this basin in the past, the current body of water formed in 1905 when a levee break along the Colorado River caused flows from the Colorado River to enter the basin for about 18 months. Since 1905, the Sea has fluctuated in size with varying inflow, and it recently has had a surface area of 365 square miles. A balance between inflowing water and evaporation sustains the Sea. With no outlet, any salts that are dissolved in the inflow are trapped, although some do precipitate. Salt concentrations are currently about 44,000 milligrams per liter (mg/L), or about 25 percent higher than ocean water. Salinity will continue to rise under current conditions. It is highly likely that in the future, the inflow to the Sea will be less than it has been in the past. A reduction in inflow would cause the Sea to shrink and cause salinity to rise faster than it would have without a reduction in inflow. A gradual increase in salinity and its consequences was recognized soon after the Sea was formed. Formulation of salinity control measures was reported as early as the mid-1950s. Since then, many alternatives have been proposed and analyzed. The alternatives presented in this report were developed to address the goals contained in the Salton Sea Reclamation Act of 1998. The Act directs the Secretary of the Interior to study options for managing the salinity and elevation of the Sea in order to preserve fish and wildlife health and enhance opportunities for recreation use and economic development while continuing the Sea’s use as a reservoir for irrigation drainage. The Act required that certain options be analyzed and required consideration of reduced inflows down to 800,000 acre-feet or less per year. Consideration of any option that included importation of water from the Colorado River was prohibited. Reporting requirements of the Act were met on January 27, 2000, when Secretary Babbit forwarded a draft EIS/EIR and several other reports to Congress. Since then, analyses have continued on options presented in those reports and on new options. The development and transmission of this report is not required by law. This report provides a summary of the current status of the evaluation of alternatives currently under consideration. The primary purpose of the planning study was to evaluate possible methods of controlling the salinity and elevation of the Sea. The study also includes elements that address other issues at the Sea, such as high levels of nutrients. Fourteen alternatives providing a range of salinity and elevation control benefits and costs are presented in this report. For ease of presentation and understanding, alternatives were divided into the following categories: Salinity control alternatives Salinity and elevation control alternatives Causeway/barrier alternatives (the terms causeway and barrier are interchangeable in this report) Specialized diking alternatives Methods to control salinity and elevation include pumping water out of the Sea with discharge to some remote location; pumping water out of the Sea with discharge to local desalting plants or evaporation ponds, possibly in combination with enhanced evaporation systems that would require disposal of salt residues near or within the Sea; and dividing the Sea through the construction of dikes so that one portion serves to concentrate and isolate salts from the remainder of the Sea. Each alternative is discussed briefly below. The present value cost estimates for each alternative are also mentioned below. Present value cost includes the initial construction cost plus funds that would need to be set aside today to fund operation, maintenance, and energy over a 30-year period. This status report makes no recommendation regarding future action relating to restoration of the Salton Sea. In fact, given that all of the alternatives identified to date are extremely expensive, it is difficult, if not impossible, to make any recommendation without a decision by Congress regarding the relative importance of the Sea in light of other pressing national priorities.

San Gorgonio Pass Subbasin Groundwater Sustainability Plan

San Gorgonio Pass Groundwater Sustainability Agency | January 28th, 2022

Satellite observations indicate that chia uses less water than other crops in warm climates

Nature Portfolio (Springer Nature) | September 30th, 2024

SB-72 The California Water Plan: long-term supply targets

State of California | September 8th, 2025

Existing law requires the Department of Water Resources to update every 5 years the plan for the orderly and coordinated control, protection, conservation, development, a

Existing law requires the Department of Water Resources to update every 5 years the plan for the orderly and coordinated control, protection, conservation, development, and use of the water resources of the state, which is known as “The California Water Plan.” Existing law requires the department to include a discussion of various strategies in the plan update, including, but not limited to, strategies relating to the development of new water storage facilities, water conservation, water recycling, desalination, conjunctive use, and water transfers, that may be pursued in order to meet the future needs of the state. Existing law requires the department to establish an advisory committee to assist the department in updating the plan. This bill would revise and recast certain provisions regarding The California Water Plan to, among other things, require the department to expand the membership of the advisory committee to include, among others, tribes, labor, and environmental justice interests. The bill would require the department, as part of the 2033 update to the plan, to update the interim planning target for 2050, as provided. The bill would require the target to consider the identified and future water needs for all beneficial uses, including, but not limited to, urban uses, agricultural uses, tribal uses, and the environment, and ensure safe drinking water for all Californians, among other things. The bill would require the plan to include specified components, including a discussion of the estimated costs, benefits, and impacts of any project type or action that is recommended by the department within the plan that could help achieve the water supply targets. The bill would require the department to report to the Legislature the amendments, supplements, and additions included in the updates of the plan, together with a summary of the department’s conclusions and recommendations, in the session in which the updated plan is issued. The bill would also require the department to conduct public workshops to give interested parties an opportunity to comment on the plan.

Seasonal variation in total water storage in California inferred from GPS observations of vertical land motion

American Geophysical Union (AGU) | March 12th, 2014

GPS is accurately recording vertical motion of Earth's surface in elastic response to seasonal changes in surface water storage in California. California's mountains subs

GPS is accurately recording vertical motion of Earth's surface in elastic response to seasonal changes in surface water storage in California. California's mountains subside up to 12 mm in the fall and winter due to the load of snow and rain and then rise an identical amount in the spring and summer when the snow melts, the rain runs off, and soil moisture evaporates. We invert the GPS observations of seasonal vertical motions to infer changes in equivalent water thickness. GPS resolves the distribution of change in total water across California's physiographic provinces at a resolution of 50 km, compared to 200 km resolution from the Gravity Recovery and Climate Experiment. The seasonal surface water thickness change is 0.6 m in the Sierra Nevada, Klamath, and southern Cascade Mountains and decreases sharply to about 0.1 m east into the Great Basin and west toward the Pacific coast. GPS provides an independent inference of change in total surface water, indicating water storage to be on average 50% larger than in the NLDAS‐Noah hydrology model, likely due to larger changes in snow and reservoir water than in the model.

Securing Color River Supplies - An Urban-Agriculture Partnership in the Palo Verde Valley

Metropolitan Water District of Southern California (MWD) | March 16th, 2022

Selected trace-elements in alluvium and rocks, western Mojave Desert, southern California

Journal of Geochemical Exploration (Elsevier) | September 3rd, 2018

Concentrations of twenty-seven elements, including naturally-occurring water-quality contaminants arsenic, chromium, and uranium, were measured in 217 samples of alluviu

Concentrations of twenty-seven elements, including naturally-occurring water-quality contaminants arsenic, chromium, and uranium, were measured in 217 samples of alluvium and rock from the western Mojave Desert, southern California, using portable (pXRF) and laboratory (LXRF) X-ray fluorescence. Comparison of measurements with NIST-traceable standards was good, although pXRF overestimated iron compared to LXRF. Results suggest pXRF survey data are sufficiently accurate to assess regional geochemical differences in geologic-source terrains. Principal component analysis showed rubidium and potassium were associated with alluvium eroded from felsic terrain, while iron, copper, chromium, and to a lesser extent titanium, manganese, and nickel were associated with alluvium eroded from mafic terrain. Zinc, vanadium, and arsenic were associated with alluvium eroded from hydrothermal terrain. Elemental assemblages associated with different source terrains were traced spatially to identify the source and composition of alluvium composing aquifers pumped for water supply. Changes in geologic source terrain to the Mojave River, associated with movement along the San Andreas Fault over the past one to five million years, reduced the mafic fraction and increased the felsic fraction of alluvium deposited to the regionally important floodplain aquifer along the Mojave River—lowering chromium concentrations in alluvium through geologic time. Comparison of pXRF and sequential extraction data from 40samples showed arsenic and uranium were more abundant on the surfaces of mineral grains, while chromium and vanadium remained mostly within unweathered mineral grains—suggesting arsenic and uranium may be more readily mobilized into groundwater with changes in pH, redox, or ionic strength than chromium or vanadium.

Selenium Hazards in the Salton Sea Environment— Summary of Current Knowledge to Inform Future Wetland Management

U.S. Geological Survey (USGS) | July 20th, 2023

Quaternary marine and continental shales in the western United States are sources of selenium that can be loaded into the aquatic environment through mining, agricultural

Quaternary marine and continental shales in the western United States are sources of selenium that can be loaded into the aquatic environment through mining, agricultural, and energy production processes. The mobilization of selenium from shales through agricultural irrigation has been recognized since the 1930s; however, discovery of deformities in birds and other wildlife using agricultural habitats during the 1980s spurred studies to determine the extent and effects of the contamination. Through these early studies, researchers determined that biota in the Salton Sea drainage basin was at risk from legacy selenium contamination in the Colorado River watershed.

Senate Bill No. 1157

State of California | September 28th, 2022