The Development of Nutrient Criteria for Ecoregions within: California, Arizona, and Nevada

U.S. Environmental Protection Agency (EPA) | January 1st, 2002

Development of regional nutrient criteria is one component of a larger strategy to address water quality problems associated with nutrient over-enrichment and cul

Development of regional nutrient criteria is one component of a larger strategy to address water quality problems associated with nutrient over-enrichment and culturally-induced accelerated rates of eutrophication of waterbodies in the U.S. The U.S. Environmental Protection Agency (EPA) and Department of Agriculture have several active program initiatives to address the nutrient overenrichment problem. These programs address point and nonpoint sources of pollution, evaluate public health impacts from animal feeding operations, conduct research and monitoring to provide data and assessment techniques to better characterize the problem, and have offer nutrient management policies to provide practical support to agricultural operations to reduce the export of nutrients from their lands. The purpose of the regional nutrient criteria development process is to provide numeric targets for the various nutrient management programs that are regionally appropriate by reflecting geographic variations of waterbody response to nutrients. The current nutrient criteria development process for California and EPA Region IX (California, Nevada, Arizona, and Hawaii) started with the publication of the National Strategy for the Development of Regional Nutrient Criteria (EPA 1998) in June 1998.

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 Disposition of Mining Debris in California

Scientific American | July 18th, 1891

Among the reports submitted to the last Congress was one from the Secretary of War on the treatment of mining debris in California. The report contained the conclusion

Among the reports submitted to the last Congress was one from the Secretary of War on the treatment of mining debris in California. The report contained the conclusions of the Board of Engineer officers which was prepared in compliance with an act of Congress, approved October 1st, 1888, which directed that three officers from the Engineer Corps of the United States army be constituted a commission for the purpose of making a thorough examination of the mining debris question in California, and determining whether some plan cannot be devised whereby the present conflict between the mining and farming sections may be adjusted, and the mining industry rehabilitated.

The doctrine of reserved water rights. What are federal and tribal reserved water rights?

California Department of Water Resources (DWR) | January 1st, 2009

The doctrine of reserved water rights evolved to ensure that Indian reservations and public lands set aside by the federal government would have sufficient water to fulfi

The doctrine of reserved water rights evolved to ensure that Indian reservations and public lands set aside by the federal government would have sufficient water to fulfill the purposes for which they were established. Whereas most western water rights (state-based appropriative rights) have a priority date based on when water was first put to beneficial use, federal reserved water rights have a priority date that goes back at least as far as the date on which the lands were set aside. The reserved water rights doctrine is rooted in a number of judicial decisions, beginning with a U.S. Supreme Court decision that has come to be called the Winters Doctrine. The case of Winters vs United States involved a dispute between Native Americans of the Ft. Belknap Reservation and nonnative settlers over the use of the Milk River in Montana. When the water use of the settlers upstream from the reservation interfered with the Indians' water need for large Irrigation diversions, the U.S. government filed a lawsuit on the reservation's behalf. The Winters decision held that when Congress created the Ft. Belknap Reservation, sufficient water to make the Indians a "pastoral and civilized People" was implicitly set aside. Therefore, although the normative settlers had perfected their water rights under Montana state law, the water right of the Indians of Ft. Belknap was prior, or senior in use.

The Draft State Water Project Delivery Capability Report 2021

California Department of Water Resources (DWR) | December 31st, 2021

The California Department of Water Resources (DWR) has authority under state law to construct, operate, and maintain the State Water Project (SWP) to manage, store and de

The California Department of Water Resources (DWR) has authority under state law to construct, operate, and maintain the State Water Project (SWP) to manage, store and deliver water for the benefit of the State. This report is intended to provide information about the key factors affecting the operation of the SWP in California, its long-term capability as a source of water for beneficial use, and an estimate of its current delivery capability. This report meets the requirements of Attachment B to the Monterey Plus Settlement Agreement of May 2003. Water provided by the SWP is a major source of the water supplies available to many SWP contractors. SWP contractors consist of 29 public entities that include cities, counties, urban water agencies, and agricultural irrigation districts. SWP contractors’ local/-regional water users have long-term contracts with the DWR for all, or a portion of their water supply needs. Thus, the delivery capability of water from the SWP system is an important component in the water supply planning of its recipients, and ultimately affects the amount of water available for beneficial use in California. The availability of these water supplies may be highly variable. A sequence of relatively wet water years1 may be followed by a varying sequence of dry or critically dry years. Having good and reliable estimates on how much water each contractor will receive each year —- whether it be a wet water year, a critical year, or somewhere in between -- gives contractors a better sense of the degree to which they may need to implement increased conservation measures, or plan for new facilities or back up sources of water to meet their needs. The geography of California and the infrastructure of water transfer from the source areas, located in the Sierra Mountain Range, to areas of demand for water, makes the Sacramento-San Joaquin Delta a key feature of the SWP’s ability to deliver water to its agricultural and urban contractors in the North Bay, the South Bay, California Central Valley, and Southern California. All but five of the 29 SWP contractors receive water deliveries by diversions from the Delta. These water diversions are pumped by either the Harvey O. Banks or Barker Slough pumping plants. DWR and the United States Bureau of Reclamation (USBR), the managing entities of the two statewide systems of water transfer in California, face numerous challenges in the operation of their diversion facilities in the Delta, and are regulated by several state and federal agencies to maintain, and enhance the Delta’s long-term sustainability. Maintaining suitable quality of water flowing in the channels of the Delta for the numerous in-basin beneficial uses, and the protection of endangered and threatened fish species are important factors of concern for the operators of the Delta export diversion facilities. Ongoing regulatory restrictions, such as those aimed at protecting the estuary’s resident and migratory fish species, are major challenges to a reliable and sustainable water delivery capability of both, SWP and the Central Valley Project (CVP) systems. Complications induced by climate change also pose the threat of increased variability in the frequency and magnitude of floods and droughts. The projected sea level rise caused by the increase in average temperature complicate efforts to manage salinity levels in the channels affected by tides. Additionally, higher ocean levels could result in more frequent water quality degradation in the Delta channels requiring additional Delta outflow to maintain water quality objectives. The 2021 Final Main Report (released at the end of March 2022) may include further information on climate change. Previously, the climate change scenario results were only discussed and presented in the Technical Addendum which is not published during the draft phase of the Delivery Capability Report (DCR). Other challenges include continued subsidence of Delta islands, many of which are already below sea level and supported by relatively unstable levee systems. Thus, the threat of a catastrophic levee failure becomes more significant as water pressure increases against the already fragile levees. The analyses in this report factor in all the current regulations governing SWP and CVP operations in the Delta and assumptions about water uses upstream in the Sacramento River and San Joaquin River watersheds. Analyses were conducted that determined the amounts of water that SWP contractors receive and the amounts of water they choose to hold for use in a subsequent year. SWP Delta exports have decreased since 2005, although the bulk of the change occurred between 2005 and 2009 and in 2019. The former reduction is due to the Delta regulations which constrained exports that culminated in the federal Biological Opinions (BiOps) which went into effect in 2008-2009. These BiOps restricted operations of the CVP and SWP diversion pumps. The later reduction is due to two main factors: 1) the amended Coordinated Operation Agreement (COA) with accompanying project operation changes which reduced SWP exports and increased CVP exports, and (2) a more conservative operation of Lake Oroville by the SWP. Many of the same assumptions on SWP operations described in the 2019 Report remains the same in this update for 2021, however, there were a few notable changes. These include the transition from CalSim II to CalSim 3 and CVP and SWP operational refinements. As a result, the differences between the 2019 and 2021 Reports can be attributed primarily to differences in hydrology, spatial and temporal expansion, more explicit groundwater and surface water interaction representation, and operational refinements. The most salient findings in this report are: Under existing conditions, the estimated average annual delivery of Table A water for this 2021 Report is 2,309 thousand acre-feet (TAF)/year, 105 TAF less than the 2,414 TAF/year estimated for the 2019 Report (Table 5-2). The likelihood of existing condition SWP Article 21 deliveries (supplemental deliveries to Table A water) being greater than 20 TAF/year has decreased by 20% relative to the likelihood presented in the 2019 Report (Figure 5-7).

The drivers and the implications of marine heatwaves

National Academy of Sciences (NAS) | June 24th, 2022

The Ecological Significance of the Submarine Discharge of Groundwater

Commonwealth Scientific and Industrial Research Organisation (CSIRO Publishing) | December 15th, 1980

Discharge of groundwater into the sea is widespread. Overlooking it may lead to serious misinterpretations of ecological data in studies of coastal pollution, of benthic

Discharge of groundwater into the sea is widespread. Overlooking it may lead to serious misinterpretations of ecological data in studies of coastal pollution, of benthic zonation and productivity, and of the flux of dissolved substances within and between bottom sediments and overlying water. Data are presented indicating that in the Perth region of Western Australia, submarine groundwater discharge delivers several times as much nitrate to coastal waters as does river runoff.

The Economic Impact of the Westlands Water District on the Local and Regional Economy

Westlands Water District | October 11th, 2016

To anyone who visits the Westlands Water District (the District), the one reality that is most obvious to the observer is that agriculture IS the economy in the communiti

To anyone who visits the Westlands Water District (the District), the one reality that is most obvious to the observer is that agriculture IS the economy in the communities within and immediately surrounding the Westlands Water District. It is an area characterized by wide open fields-often populated with crops and occasional small pockets of residential and (rarer) retail-usually at the intersections of roads. Not only is agriculture the primary employer, but government, agricultural support industries and the limited general retail sector comprise the full course of jobs within the district and its immediate environs. Nearly every business in the district is related to agriculture or supporting the needs of the workers who support those working in agriculture. Westlands Water District is perched on the eastern side of Interstate 5 in the Central Valley covering the geography between roughly Kettleman City in the south and Firebaugh in the north. As the largest agricultural water district in the nation, it plays a central role in the economies of both Fresno and Kings Counties. This analysis unravels the story of Westlands' contributions to the local economy, exploring the demographics and economy of the region, agriculture's major role in that economy, estimating the economic contributions of growers within the District's boundaries, and providing a preliminary assessment of the consequences of current water policies on crop production, and giving a preview of what some of the implications of those changes may be.

The Economic Impact on the Local Economy of Irrigated Agriculture in the Paso Robles Area and Potential Impacts of the Sustainable Groundwater Management Act

California Polytechnic State University, San Luis Obispo (CSU) | August 26th, 2020

The purpose of this study is to analyze the economic impact of the agricultural and wine industry within the Paso Robles Subbasin and AVA and San Luis Obispo County and t

The purpose of this study is to analyze the economic impact of the agricultural and wine industry within the Paso Robles Subbasin and AVA and San Luis Obispo County and to assess the economic impact of potential changes in the agricultural industry as a result of the Paso Robles Subbasin Groundwater Sustainability Plan that will reduce water allocations and/or increase the cost of water in the basin from 2020 – 2040 and beyond.

The Economic Impacts of Central Valley Salinity

California State Water Resources Control Board (SWRCB) | March 20th, 2009

The study team was charged with measuring the economic impacts of increasing salinity in the Central Valley to the year 2030. The study was conducted assuming that there

The study team was charged with measuring the economic impacts of increasing salinity in the Central Valley to the year 2030. The study was conducted assuming that there is no change in current policy and, as such, represents the economic impacts associated with taking no action. Additionally, the study was conducted on an aggregate valley-wide basis that required averaging the effects of salinity and, in some cases, costs. The growth in salinity in the Central Valley was based on two factors. The first factor was the growth of the areas of shallow saline groundwater based on 30 years of historical records. The second factor was increased levels of salts that result indirectly from imported water. Based on increasing salinity stemming from these factors, the direct economic effects on industry, residential, food processing, confined animal operations, and irrigated agricultural production in the Central Valley were measured. Economic and physical effects were quantified using different physical and economic models. In addition, the team undertook a substantial survey of the population in the Central Valley to establish non-market values for increased salinity and its effect on non-market activities. The study results showed that if salinity increases at the current rate until 2030, the direct annual costs will range from $1 billion to $1.5 billion. Total annual income impacts to California will range between $1.7 billion to $3 billion by 2030. The income impacts to the Central Valley will range between $1.2 billion and $2.2 billion.  The production of goods and services in California could be reduced from $5 billion to $8.7 billion a year. The Central Valley output reduction would range between $2.8 billion to $5.3 billion. Furthermore, there is $145 million per year of non-market costs. In terms of job losses the increase in salinity by 2030 could cost the Central Valley economy 27,000 to 53,000 jobs. California could lose 34,000 to 64,000 jobs. In short, the problem is substantial and growing steadily. The magnitude of the economic and employment losses justifies a more detailed study of remedial action and correction policies.