The Colorado River Aqueduct

Metropolitan Water District of Southern California (MWD) | July 5th, 2021

The Complete Story of the Project: Its Purposes, Plans, and Progress of Construction

Scientific American | September 1st, 1932

IN THE Black Canyon of the Colorado, where the river forms the boundary between the states of Arizona and Nevada, the Government of the United States through the Depa

IN THE Black Canyon of the Colorado, where the river forms the boundary between the states of Arizona and Nevada, the Government of the United States through the Department of the Interior and directly by the Bureau of Reclamation has started construction of Hoover Dam. On September 17, 1930, constructional activities were formally inaugurated by Secretary of the Interior Ray Lyman Wilbur, and since that date, under the supervision and control of the Bureau of Reclamation, headed by Commissioner Elwood Mead, the building of the dam has progressed rapidly. Construction operations are carried out under the direction of R. F. Walter, Chief Engineer of the Bureau of Reclamation, represented in the field by the writer.

The disappearing Salton Sea: A critical reflection on the emerging environmental threat of disappearing saline lakes and potential impacts on children's health

Science of the Total Environment (Elsevier) | February 6th, 2019

Changing weather patterns, droughts and competing water demands are dramatically altering the landscape and creating conditions conducive to the production of wind-blown

Changing weather patterns, droughts and competing water demands are dramatically altering the landscape and creating conditions conducive to the production of wind-blown dust and dust storms. In California, such factors are leading to the rapid shrinking of the Salton Sea, a 345 mile2 land-locked “sea” situated near the southeastern rural border region known as the Imperial Valley. The region is anticipated to experience a dramatic increase in wind-blown dust and existing studies suggest a significant impact on the health and quality of life for nearby residents of this predominantly low-income, Mexican-American community. The discussion calls attention to the public health dimensions of the Salton Sea crisis. We know little about the possible long-term health effects of exposure to mobilized lakebed sediments or the numerous toxic contaminants that may become respirable on entrained particles. We draw on existing epidemiological literature of other known sources of wind-blown dust, such as desert dust storms, and related health effects to begin to understand the potential public health impact of wind-blown dust exposure. The increased production of wind-blown dust and environmental exposures to such non-combustion related sources of particulate matter are a growing health threat, due in part to drought coupled with increasing pressures on limited water resources. Recent population-based studies have linked dust storms with cardiovascular mortality, asthma hospitalization and decrease in pulmonary function in both adults and children. A growing number of studies provide evidence of the acute health effects of wind-blown dust exposures among children, which with repeated insults have the potential to influence respiratory health over time. The shrinking of the Salton Sea illustrates a public health and environmental justice crisis that requires action and attention to protect the health and well-being of local communities.

The Effect of a Receding Saline Lake (The Salton Sea) on Airborne Particulate Matter Composition

American Chemical Society (ACS) | July 12th, 2017

The composition of ambient particulate matter (PM) and its sources were investigated at the Salton Sea, a shrinking saline lake in California. To investigate the influenc

The composition of ambient particulate matter (PM) and its sources were investigated at the Salton Sea, a shrinking saline lake in California. To investigate the influence of playa exposure on PM composition, PM samples were collected during two seasons and at two sites around the Salton Sea. To characterize source composition, soil samples were collected from local playa and desert surfaces. PM and soil samples were analyzed for 15 elements using mass spectrometry and X-ray diffraction. The contribution of sources to PM mass and composition was investigated using Al-referenced enrichment factors (EFs) and source factors resolved from positive matrix factorization (PMF). Playa soils were found to be significantly enriched in Ca, Na, and Se relative to desert soils. PMF analysis resolved the PM10 data with four source factors, identified as Playa-like, Desert-like, Ca-rich, and Se. Playa-like and desert-like sources were estimated to contribute to a daily average of 8.9% and 45% of PM10 mass, respectively. Additionally, playa sources were estimated to contribute to 38–68% of PM10 Na. PM10 Se concentrations showed strong seasonal variations, suggesting a seasonal cycle of Se volatilization and recondensation. These results support the importance of playas as a source of PM mass and a controlling factor of PM composition.

The Enduring Role of Tribes in the Colorado River Basin

Water and Tribes Initiative | July 1st, 2019

The purpose of this policy brief is to explain the origin, rationale, and purpose of the Water & Tribes Initiative in the Colorado River Basin. As explained more fully be

The purpose of this policy brief is to explain the origin, rationale, and purpose of the Water & Tribes Initiative in the Colorado River Basin. As explained more fully below, the long-term objectives of this Initiative are to: • Enhance the capacity of tribes to advance their needs and interests with respect to water management in the basin; and • Advance sustainable water management through collaborative decision-making.

The Evolution of Metropolitan’s Agricultural Partnerships

Metropolitan Water District of Southern California (MWD) | August 5th, 2022

The Future Hydrology of the Colorado River Basin

Utah State University | August 31st, 2020

Long-range planning of the water supply provided by the Colorado River requires realistic assessments of the impact of a continuation of the current drought that began in

Long-range planning of the water supply provided by the Colorado River requires realistic assessments of the impact of a continuation of the current drought that began in 2000, the impact of potentially extreme future droughts, and the long-term and progressive decline in watershed runoff that is caused by a warming climate. Water-supply managers want to know the maximum plausible stresses to water users so that plans for conservation, reservoir operations, and/or construction of new infrastructure can be properly developed. River managers want to know the implications of various water-supply plans on the flow-regime and water-quality characteristics of the Colorado River and its headwater branches in order to develop natural resource management plans that maintain desired attributes of river ecosystems. Although it is relatively easy to qualitatively describe scenarios of drought or water abundance, it is much harder to quantitatively estimate likely future conditions. In the white paper, we developed methods to make such quantitative estimates, thereby providing an approximate answer to the question, “How dry might future conditions in the Colorado River watershed become?” It is difficult to assign a probability to this assessment, and our analysis is guided by the principle that what has happened in the past might happen again in the future.

The Inundation of the Salton Basin by the Colorado River and How It Was Caused

Scientific American | April 14th, 1906

If the Colorado River continues to flow through the channel which it has been occupying during the last six months, the geography of the Southwest must be radically ch

If the Colorado River continues to flow through the channel which it has been occupying during the last six months, the geography of the Southwest must be radically changed, for at the present time but little water from the river reaches the Gulf of California, which until recently has formed its main estuary. Except when the river is in flood, the bulk of the water flows into what is known as the Salton Sink in southern California-a distance of fully 160 miles from the gulf.  The new channel of the Colorado takes a northwesterly course, while the channeI it formerly occupied is nearly south. It is perhaps needless to say that this watercourse is not only one of the most important in the Southwest, but is notable for the immense volume of water which it carries, especially during the flood seasons. But the quantity of detritus which it holds in solution is enormous, and is nearly equal to that carried down by the Mississippi at certain seasons of the year, owing to the topography of the region which drains into it. An idea of the quantity of water carried by the Colorado at different times of the year can be gained, when it is stated that actual measurements indicate a flow ranging as high as 30,000 cubic feet per second. It is estimated that if the silt and other material brought down the river in the course of a year were spread evenly over a given 'surface, it would cover no less than 35,000 acres to a minimum depth of one foot. Consequently, the Colorado is almost as much of a "land maker" as the Mississippi, acting like a gigantic suction dredge in carrying away the material in its vicinity and depositing it upon the lowlands near its mouth and in the Gulf of California.

The Ives Expedition of 1858

Imperial Irrigation District (IID) | October 1st, 1956

The Lower Colorado Basin Fiscal Years 2019 & 2020

U.S. Bureau of Reclamation (USBR) | January 4th, 2021