Summary of the MeHg Panels of the 2004 CalFed Science Conference

San Francisco Estuary Institute (SFEI) | November 22nd, 2004

Mercury (Hg) can become an environmental problem when sulfate-reducing anaerobic bacteria, in the presence of organic substrates, form methylmercury (MeHg), a highly toxi

Mercury (Hg) can become an environmental problem when sulfate-reducing anaerobic bacteria, in the presence of organic substrates, form methylmercury (MeHg), a highly toxic compound that endangers wildlife and people by accumulating in their food. The spatial and temporal variation in MeHg production is mainly a function of the availability of inorganic mercury to methylating bacteria. Typically only a small percentage (e.g. < 5 %) of total inorganic mercury is available for methylation. The amount of MeHg that actually becomes available for bioaccumulation depends on many environmental factors operating at different spatial scales, from watersheds to microbes. Scientists are working to prioritize these factors for management actions.

Summary of the Proposed Northeastern Arizona Indian Water Rights Settlement Agreement for Public Discussion Purposes

Navajo Nation Water Rights Commission | May 22nd, 2024

Summary Report on the Transactions of the Smelt Working Group in Water Year 2014

Delta Stewardship Council (Delta Council) | August 29th, 2014

The Bay‐Delta Fish and Wildlife Office (BDFWO) has prepared this report to summarize the implementation the U.S. Fish and Wildlife Service’s (Service) biological opi

The Bay‐Delta Fish and Wildlife Office (BDFWO) has prepared this report to summarize the implementation the U.S. Fish and Wildlife Service’s (Service) biological opinion on the Central Valley Project (CVP) and State Water Project (SWP) Long‐term Operations (BiOp) in Water Year (WY) 2014. In addition to background information pertinent to implementation of the BiOp , this report provides a summary of the transactions of the Smelt Working Group (SWG), as well as water operations and during WY 2014. The SWG is a technical team that evaluates biological and technical issues regarding Delta Smelt (Hypomesus transpacificus) and develops recommendations for consideration by the Service during implementation of the BiOp’s Reasonable and Prudent Alternative (RPA) actions. During WY 2014 the SWG made no recommendations for more restrictive water operations and the Service issued no determinations to reduce water exports.

Summary Report on the Transactions of the Smelt Working Group in Water Year 2018

Delta Stewardship Council (Delta Council) | November 1st, 2018

Summary report: Green sturgeon, longfin smelt, and dredging operations in the San Francisco Estuary

San Francisco Estuary Institute (SFEI) | December 1st, 2009

In 2009, California Department of Fish and Game Commission listed longfin smelt (Spirinchus thaleichthys) as threatened, and NOAA formally adopted “take” provisions f

In 2009, California Department of Fish and Game Commission listed longfin smelt (Spirinchus thaleichthys) as threatened, and NOAA formally adopted “take” provisions for green sturgeon (Acipenser medirostris Ayres). These changes in the management status, and associated permitting issues, have prompted renewed interest among [long term management strategy] LTMS participants in the management of these native fish. In response, LTMS held symposia on December 2 and 3, 2009, to review and consider the science, management, and policy related to dredging activities and these species. A primary stressor to both species is reduction of appropriate habitat, due to water diversion activities and other basin-scale modifications in water flow. Local studies of dredging have shown little evidence of direct entrainment for either species, and the frequency of encounter with sites of dredging activity is likely to be very low. Nevertheless, spatial and temporal patterns of population movements and reproductive activity vary from year to year, making it difficult to employ an environmental work windows approach. Available information is limited on other direct effects of dredging, including sediment contamination, habitat modification, and underwater noise. Indirect effects due to maintenance of active navigation channels pose potential concerns. In particular, introduction of invasive species, and mortality due to propeller strikes, both warrant attention. As a follow up step to the symposia, we recommend that LTMS host a workshop targeted towards specific LTMS management needs for green sturgeon and longfin smelt. The workshop should include LTMS participants, the scientists that presented at the symposium, and dredging operators, and could focus on the integration of current research findings into tools that would be useful for managers. Appropriate tools for consideration include predictive or descriptive models of species distribution, and of potential impacts of various dredging activities. There should also be consideration of management approaches that broadly address the primary ecosystem-level stressors for green sturgeon and longfin smelt, rather than employing small scale project-level mitigation. In particular, an integrated regional restoration and monitoring program may be the most effective approach to improve the health of the species.

Supplement to the 2007 Colorado River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead

U.S. Bureau of Reclamation (USBR) | May 6th, 2024

This ROD revises the 2007 Interim Guidelines for the near-term operation of Glen Canyon and Hoover Dams to address the potential for continued low-runoff conditions in th

This ROD revises the 2007 Interim Guidelines for the near-term operation of Glen Canyon and Hoover Dams to address the potential for continued low-runoff conditions in the Basin. Reclamation has concluded that the potential impacts of low-runoff conditions pose unacceptable risks to routine operations of Glen Canyon and Hoover Dams during the remainder of the interim period (through the end of the 2026 operating year) and that modified operating guidelines need to be expeditiously developed.

Support for Sediment Bioaccumulation Evaluation: Toxicity Reference Values for San Francisco Bay

San Francisco Estuary Institute (SFEI) | December 3rd, 2018

This special study of the Regional Monitoring Program for Water Quality in San Francisco Bay was conducted to support the Dredged Material Management Office (DMMO) proces

This special study of the Regional Monitoring Program for Water Quality in San Francisco Bay was conducted to support the Dredged Material Management Office (DMMO) process of evaluating results from bioaccumulation testing performed for routine dredging projects. The goal was to use the current DMMO methodology for selecting Toxicity Reference Values (TRVs) from the US Army Corps of Engineers Environmental Residue-Effects Database (ERED), in order to develop a standard list of TRVs for San Francisco Bay. TRVs are used as a conservative screening tool to efficiently evaluate whether observed invertebrate test organism body burdens could indicate adverse ecological effects on benthic organisms in situ. Currently, there are no published standard TRVs for the Bay, and TRV selection is presently performed on a case-by-case basis during the evaluation of bioaccumulation testing results submitted by individual dredgers. A standard list would promote consistent application of the methodology and improve the efficiency of dredging project evaluations. 

Supporting sustainable groundwater management

California Agriculture (UCANR) | March 13th, 2018

Implementation of the 2014 Sustainable Groundwater Management Act is on schedule. The first phase, completed in 2017, created a new layer of local government —

Implementation of the 2014 Sustainable Groundwater Management Act is on schedule. The first phase, completed in 2017, created a new layer of local government — groundwater sustainability agencies. Now, these new agencies must prepare groundwater sustainability plans. These plans will lay out a basic reckoning for every overdrafted basin: without additional water to replace groundwater pumping or to recharge aquifers, there will be less available to produce food, supply homes and businesses, and ensure there is enough water for the environment.

Supreme Court Declines to Review Ninth Circuit Decision Applying Federal Reserved Water Rights Doctrine to Groundwater

Congressional Research Service (CRS) | December 21st, 2017

The 2012-2016 drought in California and parts of other western states may have ended, but availability of water will continue to present issues for Cong

The 2012-2016 drought in California and parts of other western states may have ended, but availability of water will continue to present issues for Congress to consider. While state, rather than federal , law typically governs allocations of water resources within a state , there are exceptions where federal law does affect water allocation. Thefederal reserved water rights doctrine, for example, holds that when the federal government reserves federal lands for a particular purpose (such as for a tribal reservation or national monument ) , it impliedly reserves a right to water necessary to accomplish the purposes for which the reservation was created . Si nce 1908, when the Supreme Court established the doctrine in Winters v. United States, courts have applied it to surface waters; a March 2017 decision of the U.S. Court of Appeals for the Ninth Circuit (Ninth Circuit) held, apparently for the first time, that the doctrine can encompass groundwater as well. On November 27, 2017, the Supreme Court declined to review this decision, which thus, for now, sets a potentially important precedent within the Ninth Circuit for other groundwater resource issues and disputes. The case Agua Caliente Band of Cahuilla Indians v. Coachella Valley Water District originated w hen a tribe sued local water agencies in 2013 in federal district court in California, alleging that the water agencies were adversely affecting the quantity and quality of water available to them by over-drafting an aquifer. Among other claims, the tribe sought a declaration that it had a federally reserved right to the groundwater underlying the reservation , which was established in the 1870s. The United States intervened to defend its ownership, tribal trust, and sovereign interests in the water rights and the tribe’s reservation. In 2015, t he district court ruled in favor of the tribe and the United States on the threshold claim that the government impliedly reserved appurtenant water sources — including underlying groundwater — when it created the tribe’ s reservation . (Subsequent phases of the Agua Caliente Band case are still being litigated. They involve whether the tribe owns the “pore space” or “storage space” of the groundwater basin.

Surface Storage - CalFed (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

California remains significantly dependent upon surface water. A review of the California Water Balance Summary, 2001-2010 (California Water Plan Update 2013, Volume 1, C

California remains significantly dependent upon surface water. A review of the California Water Balance Summary, 2001-2010 (California Water Plan Update 2013, Volume 1, Chapter 3, Table 3-2), indicates that in an average year like 2010, about 65 maf (million acre-feet) (more than 80 percent) of 80 maf total dedicated and developed water supply is associated with surface water. Surface storage is an essential element of managing the state’s surface water resources. The naturally arid conditions found in much of California, coupled with seasonal variations of too much or too little water prompted water planners of the past to implement conveyance and storage projects to support land development, population, and economic growth. After construction, these dams captured seasonal runoff and stored it for beneficial uses during drier times. Today, these projects facilitate a larger set of water management objectives including reliable water supplies, water quality and ecosystem maintenance, flood management, and hydropower generation. In many areas of the state, surface water and groundwater are used conjunctively. Coordinated surface water and groundwater management can be either formal or informal. For example, a managed groundwater recharge program where surface water is infiltrated to an aquifer for later use is formal; excess applied surface water in agricultural areas during wetter years that increases the availability of groundwater in drier years is often more informal. Dams and surface water storage continue to be a critical tool for providing water management flexibility in California. The amount of surface water in California, as noted above, often make it a foundational integration element of more diverse local and regional water management portfolios. In addition to storing water for use by residents, businesses, and industries, these facilities provide vital supplies during warm and dry periods for growing crops and maintaining the state’s managed wildlife refuges.