Colorado River

Mapping selected trace elements and major ions, 2000-2012, Mojave River and Morongo Groundwater Basins, Southwestern Mojave Desert, San Bernardino County, California

U.S. Geological Survey (USGS) | July 1st, 2015

The population of the Mojave River and Morongo groundwater basins has grown rapidly during the last several decades, increasing from an estimated population of almost 273

The population of the Mojave River and Morongo groundwater basins has grown rapidly during the last several decades, increasing from an estimated population of almost 273,000 in 1990 (Mojave Water Agency, 2004) to more than 453,000 in 2010 (Mojave Water Agency, 2014). Groundwater is the primary source of potable water in both basins (Mojave Water Agency, 2014). Previous studies noted elevated concentrations of several trace elements, nitrate, and total dissolved solids in groundwater in portions of the two basins (Christensen and Fields-Garland, 2001; Ball and Izbicki, 2004; Izbicki and others, 2008; Mathany and Belitz, 2009; Wright and Belitz, 2010; Dawson and Belitz, 2012; and Izbicki and others, 2012). Since 2000, the U.S. Geological Survey (USGS) has collected water-quality data annually from a network of wells and has provided quality-assurance for Mojave Water Agency (MWA) data that are stored in the USGS National Water Information System (NWIS) database. The new data and results from the joint State of California and USGS Groundwater Ambient Monitoring and Assessment (GAMA) program assessments of regional water quality (these data are also stored in NWIS), in combination with ongoing MWA/USGS groundwater-quality monitoring provide a timely opportunity for mapping of groundwater quality in the Mojave River and Morongo groundwater basins. The purpose of this report is to provide maps and time-series plots of concentrations of selected water-quality constituents (arsenic, boron, chromium-6, total chromium, dissolved oxygen, fluoride, iron, manganese, nitriate plus nitrite as nitrogen, total dissolved solids, uranium, and vanadium) in the Mojave River and Morongo groundwater basins using data collected by the USGS and MWA from 2000 to 2012. These maps and plots can be accessed on this website.

Maxey-Eakin Methods for Estimating Groundwater Recharge in the Fenner Watershed, Southeastern California

U.S. Department of Energy (DOE) | May 15th, 2000

Recent review comments by the U.S. Geological Survey, Water Resources Division on the Cadiz Groundwater Storage and Dry-Year Supply Program Draft Environmental Planning

Recent review comments by the U.S. Geological Survey, Water Resources Division on the Cadiz Groundwater Storage and Dry-Year Supply Program Draft Environmental Planning Report were accompanied by an independent recharge estimate to the Fenner Basin based on a Maxey-Eakin method. The following report has analyzed WRD's recharge estimates and concludes that those results greatly underestimate annual recharge and lack credibility. Among the reasons outlined are 1) WRDÕs lack of geographic scale and context when analyzing precipitation-elevation data, 2) WRD's use of an uncalibrated Maxey-Eakin model, and 3) WRD's lack of direct observational experience in the eastern Mojave-Fenner Basin region. This report presents a more exhaustive analysis of data, supported by direct field observations, and estimates recharge using a calibrated Maxey-Eakin model. This report concludes that the possible range in annual groundwater replenishment rates to the Fenner Basin are between 7864 acre-ft and 29,185 acre-ft. The lower limit is a worst-case-scenario. This range is consistent with original recharge estimates calculated and presented in the Cadiz Groundwater Storage and Dry-Year Supply Program Draft Environmental Planning Report.

Maximizing ENSO as a source of western US hydroclimate predictability

Climate Dynamics (Springer) | October 16th, 2019

Until recently, the El Niño–Southern Oscillation (ENSO) was considered a reliable source of winter precipitation predictability in the western US, with a historically

Until recently, the El Niño–Southern Oscillation (ENSO) was considered a reliable source of winter precipitation predictability in the western US, with a historically strong link between extreme El Niño events and extremely wet seasons. However, the 2015–2016 El Niño challenged our understanding of the ENSO-precipitation relationship. California precipitation was near-average during the 2015–2016 El Niño, which was characterized by warm sea surface temperature (SST) anomalies of similar magnitude compared to the extreme 1997–1998 and 1982–1983 El Niño events. We demonstrate that this precipitation response can be explained by El Niño’s spatial pattern, rather than internal atmospheric variability. In addition, observations and large-ensembles of regional and global climate model simulations indicate that extremes in seasonal and daily precipitation during strong El Niño events are better explained using the ENSO Longitude Index (ELI), which captures the diversity of ENSO’s spatial patterns in a single metric, compared to the traditional Niño3.4 index, which measures SST anomalies in a fixed region and therefore fails to capture ENSO diversity. The physically-based ELI better explains western US precipitation variability because it tracks the zonal shifts in tropical Pacific deep convection that drive teleconnections through the response in the extratropical wave-train, integrated vapor transport, and atmospheric rivers. This research provides evidence that ELI improves the value of ENSO as a predictor of California’s seasonal hydroclimate extremes compared to traditional ENSO indices, especially during strong El Niño events.

Measuring Progress Toward Universal Access to Water and Sanitation in California: Defining Goals, Indicators, and Performance Measures

Pacific Institute | September 15th, 2018

In January 2018, over half a million Californians were served by water utilities that were out of compliance with the Safe Drinking Water Act (SDWA). The worst outbreak o

In January 2018, over half a million Californians were served by water utilities that were out of compliance with the Safe Drinking Water Act (SDWA). The worst outbreak of Hepatitis A in recent memory occurred in 2016-2018 due to open defecation and lack of handwashing facilities for persons experiencing homelessness. California’s tribes continue to face problems of poor housing and water and sanitation service, with two-thirds of tribal communities reporting inadequate home plumbing in 2015.1 And the cost of water has increased for many, particularly among small and medium size systems, with 39 community water systems in the state charging more than $100 a month for 12 CCF of water. In response to the problem, California enacted the Human Right to Water in 2012, declaring that “Every human being has the right to safe, clean, affordable, and accessible water adequate for human consumption, cooking, and sanitary purposes.”

Microplastics in Lake Mead National Recreation Area, USA: Occurrence and biological uptake

PLOS | May 4th, 2020

Microplastics are an environmental contaminant of growing concern, but there is a lack of information about microplastic distribution, persistence, availability, and bio

Microplastics are an environmental contaminant of growing concern, but there is a lack of information about microplastic distribution, persistence, availability, and biological uptake in freshwater systems. This is especially true for large river systems like the Colorado River that spans multiple states through mostly rural and agricultural land use. This study characterized the quantity and morphology of microplastics in different environmental compartments in two large reservoirs along the Colorado River: Lakes Mead and Mohave, within Lake Mead National Recreation Area. To assess microplastic occurrence, surface water and surficial sediment were sampled at a total of nine locations. Sampling locations targeted different sub-basins with varying levels of anthropogenic impact. Las Vegas Wash, a tributary which delivers treated wastewater to Lake Mead, was also sampled. A sediment core (33 cm long, representing approximately 19 years) was extracted from Las Vegas Bay to assess changes in microplastic deposition over time. Striped bass (Morone saxatilis), common carp (Cyprinus carpio), quagga mussels (Dreissena bugensis), and Asian clams (Corbicula fluminea) were sampled at a subset of locations to assess biological uptake of microplastics. Microplastic concentrations were 0.44–9.7 particles/cubic meter at the water surface and 87.5–1,010 particles/kilogram dry weight (kg dw) at the sediment surface. Sediment core concentrations were 220–2,040 particles/kg dw, with no clear increasing or decreasing trend over time. Shellfish microplastic concentrations ranged from 2.7–105 particles/organism, and fish concentrations ranged from 0–19 particles/organism. Fibers were the most abundant particle type found in all sample types. Although sample numbers are small, microplastic concentrations appear to be higher in areas of greater anthropogenic impact. Results from this study improve our understanding of the occurrence and biological uptake of microplastics in Lake Mead National Recreation Area, and help fill existing knowledge gaps on microplastics in freshwater environments in the southwestern U.S.

Mineral Resources of the Jacumba (In-ko-pah) Wilderness Study Area, Imperial County, California

U.S. Geological Survey (USGS) | January 1st, 1987

This report presents the results of a mineral survey of part of the Jacumba (In-ko-pah) Wilderness Study Area (CDCA-368) that was designated by the Bureau of Land Mana

This report presents the results of a mineral survey of part of the Jacumba (In-ko-pah) Wilderness Study Area (CDCA-368) that was designated by the Bureau of Land Management as suitable for mineral surveys. In this report, the area studied is referred to as the "wilderness study area", or simply "the study area." The study area encompasses approximately 28,443 acres in southwestern Imperial County, Calif. Field work for this report was carried out between 1983 and 1985. Numerous mines, prospects, and claims are present in the study area, but none are being actively mined or prospected. Three sites inside the study area have identified limestone resources that total about 1.8 million tons. Four areas in the northwestern, northern, and eastern parts of the study area have high potential for undiscovered limestone resources. Two north-trending belts in the western and eastern parts of the study area have low resource potential for tungsten.

Minerals of California Bulletin No. 113

State of California | February 15th, 1938

Missing Water: The Uses and Flows of Water in the Colorado River Delta Region

Pacific Institute | September 1st, 2001

The Pacific Institute for Studies in Development, Environment, and Security is pleased to announce the release of Missing Water: The Uses and Flows of Water in the Color

The Pacific Institute for Studies in Development, Environment, and Security is pleased to announce the release of Missing Water: The Uses and Flows of Water in the Colorado River Delta Region. This new study describes the fate of the millions of acre-feet of water diverted from the Colorado River at and below Imperial Dam, and the total inflows to and outflows from the Colorado River delta region more generally. This study uses the classic hydrologic boundaries of the delta region described by Godfrey Sykes in 1937, encompassing some 3,325 square miles (8,611 square kilometers) in the states of Arizona, Baja California, California, and Sonora, including the Imperial, Mexicali, and San Luis valleys, Yuma Project lands, and the lower Coachella Valley. The study period examines the flows and uses of water in the years 1991-1998, divided into Flood and Non-Flood years to reflect the tremendous variability of mainstem Colorado River flows. Missing Water compiles flow data along the mainstem and along diversions within the delta region, the first time such data has been compiled for the region as a whole. The study also report consumptive uses of water in the agricultural and urban sectors, and estimates such use by the environment. Agricultural use is also reported for the major crops in the region, both by acreage and by water use.

Mitigating land subsidence in the Coachella Valley, California, USA: An emerging success story

International Association of Hydrological Sciences (IAHS) | April 22nd, 2020

Groundwater has been a major source of agricultural, municipal, and domestic water supply since the early 1920s in the Coachella Valley, California, USA. Land s

Groundwater has been a major source of agricultural, municipal, and domestic water supply since the early 1920s in the Coachella Valley, California, USA. Land subsidence, resulting from aquifer-system com- paction and groundwater-level declines, has been a concern of the Coachella Valley Water District (CVWD) since the mid-1990s. As a result, the CVWD has implemented several projects to address groundwater overdraft that fall under three categories – groundwater substitution, conservation, and managed aquifer-recharge (MAR). The implementation of three projects in particular – replacing groundwater extraction with surface water from the Colorado River and recycled water (Mid-Valley Pipeline project), reducing water usage by tiered-rate costs, and increasing groundwater recharge at the Thomas E. Levy Groundwater Replenishment Facility – are potentially linked to markedly improved groundwater levels and subsidence conditions, including in some of the historically most overdrafted areas in the southern Coachella Valley. Groundwater-level and subsidence monitoring have tracked the effect these projects have had on the aquifer system. Prior to about 2010, water levels persistently declined, and some had reached historically low levels by 2010. Since about 2010, however, groundwater levels have stabilized or partially recovered, and subsidence has stopped or slowed substantially almost every- where it previously had been observed; uplift was observed in some areas. Furthermore, results of Interferometric Synthetic Aperture Radar analyses for 1995–2017 indicate that as much as about 0.6 m of subsidence occurred; nearly all of which occurred prior to 2010. Continued monitoring of water levels and subsidence is necessary to inform the CVWD about future mitigation measures. The water management strategies implemented by the CVWD can inform managers of other overdrafted and subsidence-prone basins as they seek solutions to reduce overdraft and subsidence.

Mojave Region Functionally Equivalent Storm Water Resources Plan

Mojave Water Agency (MWA) | October 4th, 2017

The State of California now recognizes the importance of incorporating storm water as a potential resource in a region’s water portfolio. Historically, storm water was

The State of California now recognizes the importance of incorporating storm water as a potential resource in a region’s water portfolio. Historically, storm water was thought of as a public risk (e.g., flooding) and a source of water quality impairment. Traditional approaches for storm water focused on diverting storm water into the storm drain system which ultimately and efficiently moved said water away from populated areas; the State is now supporting watershed-based approaches where storm water and dry weather runoff can yield benefits beyond flood control, such as water supply, water quality improvement, and habitat enhancement. To incentivize use of storm water, the State of California has linked storm water resources planning to state funding. Storm water and dry weather runoff capture projects seeking funding from any California bond act approved by voters after January 1, 2014 must be included in a Storm Water Resources Plan, which meets California Water Code. Regional water planning has a long history in the Mojave region. In 2005, agencies in the Mojave service area, that share a common concern for the area’s water resources, met and agreed to develop an Integrated Regional Water Management Plan (IRWMP). The Region’s first IRWMP identified, defined, and established strategies to capitalize on all water management opportunities that were present at that time or would become possible in the Mojave Region in the future. Since that time the IRWMP has acted as a forum for regular collaboration. The IRWMP is a living document and the regional objectives as well as strategies to improvement water management are regularly updated. The IRWMP was last updated in 2014. This Mojave Region Storm Water Resource Plan (SWRP) is an extension of the IRWMP process and is meant to bring an integrated and watershed-based approach to managing and creating benefits from storm water. This SWRP is regional and multi-agency. This SWRP includes all components required by the Water Code and will be submitted to the IRWM group. This SWRP will help entities in the Mojave Region identify, prioritize, and implement storm water projects.