Californians Without Safe Water and Sanitation: California Water Plan Update 2013

California Department of Water Resources (DWR) | February 20th, 2015

This report was prepared as part of the California Water Plan Update 2013 process and is an update to the 2005 Californians without Safe Water report. It continues the d

This report was prepared as part of the California Water Plan Update 2013 process and is an update to the 2005 Californians without Safe Water report. It continues the dialogue regarding Californians without safe drinking water and/or adequate sanitation facilities and includes 14 recommendations towards ensuring that all Californians have safe drinking water and adequate sanitation facilities. The report also highlights Governor Brown’s goal of ensuring that all Californians have access to safe drinking water, as specified by his signing of Assembly Bill (AB) 685 and the release of the California Water Action Plan that includes Action 7, “Provide Safe Water for All Communities.”

Can Los Osos Valley Groundwater Basin Provide a Sustainable Water Supply?

California State University, Monterey Bay (CSUMB) | September 16th, 2010

The aquifers underlying the community of Los Osos in California are impaired by nitrate pollution from septic systems (shallow aquifers) and saltwater intrusion f

The aquifers underlying the community of Los Osos in California are impaired by nitrate pollution from septic systems (shallow aquifers) and saltwater intrusion from overdraft (lower aquifers). The development of a centralized waste water system, now in the final pre- construction stages, is proceeding concurrently with an adjudicated basin planning process involving local water purveyors in an effort to develop a management plan for a sustainable basin and water supply. Development of the wastewater system aimed at protecting the shallow aquifer has highlighted the need for a comprehensive groundwater basin management plan that focuses the County, the local water purveyors, the residents, and resource agencies on a common set of actions to stop seawater intrusion and protect the entire basin. The final basin management plan will be scrutinized and critiqued as a potential model for myriad other hydrologically independent communities that are, or will soon be, undergoing the similar quest for reliable water. Stakeholders in the Los Osos Valley Water Basin have the opportunity to lead coastal California on the difficult path toward sustainable water supply through creative local solutions that do not presume the long-term viability of imported water or desalination. While there are a number of detailed analyses and suggested actions in this report, the overarching conclusions/recommendations include: The saltwater intrusion models used in the draft EIR and technical memoranda (TMs) recently developed for the purveyor basin planning process attempt to balance saltwater intrusion against inputs and outputs to and from the aquifers. The net groundwater extraction amounts simulated in the models (corresponding to the purported safe yields) are considered aggressive (too much extraction) because they do not stabilize, or result in seaward migration, of the saltwater/freshwater interface (toward the northwest). In fact, the TM safe yield may allow the saltwater to move inland, especially if California climate becomes drier, as projected by State Government. Modeling results presented in our report indicate that if rainfall patterns persist as they have in the past, there is a reasonable chance that saltwater intrusion will progress farther, rather than remain stable, under anticipated pumping conditions. Further investigation is recommended to resolve uncertainties associated with the TM safe yields, including permeability of the regional (AT2) aquitard, how the AT2 affects lower aquifer recharge, and whether sufficient recharge will occur to prevent seawater intrusion in the upper aquifer. These uncertainties are under- appreciated in the EIR and TMs. We recommend the development of a “contingency plan” that allows flexible adaptive management to address unintended consequences that may occur following the implementation of the Los Osos Valley Wastewater Plan. Contingency plans identify mission-critical sections of the plan that have uncertainties, recommend monitoring to ascertain progress of the plan, and define remedial actions that will mitigate various unintended consequences, including divergence from, or failure of the plan. Several mission-critical arenas are discussed in the report. Rooftop rainwater harvesting and low impact development (LID) options could produce a substantial amount of water for local irrigation, reducing potable water use, while also augmenting groundwater recharge. Some LID alternatives, e.g., rain gardens and vegetated swales, can also provide attractive low-water using landscape features that may also help Los Osos residents adapt to the potential changes in groundwater levels and soil moisture content resulting from project implementation that may affect landscaping. Both on-site and community LID features will also reduce pollution of surface waters in the area. While the method used to calculate potential basin recharge from rainwater and LID features in this report is inconclusive, it suggests that the benefits of these measures may be considerable. Rainwater harvesting and LID are proven technologies that should be considered on a broad basis in the Los Osos Valley to help balance the basin and adapt to potential impacts from the project. Treatment wetlands can provide economical, efficient waste water treatment systems and/or the means to provide additional treatment, storage, and recharge of the groundwater basin. They also provide habitat and quality of life benefits (open space and passive recreational opportunities, such as hiking trails). Nitrate removal in wetlands has been studied in small scale experiments in Monterey County, has been implemented in large scale applications with positive success. Wetlands to treat surface water and wastewater have been used successfully in many communities around the world. We recommend an emphasis on agricultural exchange to maximize its benefits on seawater intrusion and help balance the basin. Tertiary-treated waste water is safe for irrigation and can reduce groundwater pumping, as well as energy and fertilizer use for farmers, with related costs savings. When well water from farms is exchanged for recycled water, potable water can be used to offset pumping causing seawater intrusion. While it is best to balance the hydrologic budget using resources within the basin, there is also an option to trade agricultural-grade treated water to regional farms in exchange for drinking grade water from wells outside the basin if ample water reserves are developed in the future. The draft Los Osos Valley sustainable water basin management plan, “Achieving a sustainable Los Osos Valley Water Basin: Framework for a 21st century basin management plan” (Wimer 2009) presents realistic, well-supported solutions for addressing the water needs of the Los Osos Community using sustainable, water saving and LID methods while preserving the basin for future use. The plan integrates methods reviewed in this report (rainwater harvesting, LID, and agriculture exchange), with urban reuse and intensive indoor and outdoor conservation to balance the basin and provide flows to sensitive ecosystems, with margins of safety that also address current and future uncertainties. We recommend that the plan is further developed, possibly with the help of water use efficiency expert, and considered for implementation. To answer the question posed by the title--yes, Los Osos can become a model of sustainable water use for coastal California if stakeholders implement reasonable conservation measures to complement an appropriate waste water treatment strategy and an adaptive management plan. The great number of uncertainties in the system makes any plan “experimental.” Given the uncertainties, due diligence will include erring on the side of caution (being conservative, not aggressive, in planned groundwater production), and devising a realistic contingency plan that includes adaptive management strategies. The Advanced Watershed Science and Policy (ENVS 660) graduate course at California State University Monterey Bay produced this report. It presents the results of extensive literature review, synthesis, and new analyses. The breadth of the report spans many of the key water supply issues facing the people of the Los Osos Valley. It provides information that can help this region move toward a sustainable water supply through innovative waste water management and sound conservation measures.

Can water reuse save the Colorado?

University of California, Los Angeles (UCLA) | April 2nd, 2025

To assess the current state of water recycling across the Colorado River Basin and its affected states, UCLA Institute of the Environment and Sustainability, in partnersh

To assess the current state of water recycling across the Colorado River Basin and its affected states, UCLA Institute of the Environment and Sustainability, in partnership with Natural Resources Defense Council, has investigated water recycling progress and policy development across the seven states in the basin.

CASGEM Alternative Monitoring Plan Fact Sheet

California Department of Water Resources (DWR) | August 15th, 2023

Causes of the Extreme Dry Conditions over California During Early 2013

American Meteorological Society (AMS) | September 30th, 2014

The state of California experienced extreme dry conditions during early 2013. In particular, January and February received 28% and 15%, respectively, of their nor

The state of California experienced extreme dry conditions during early 2013. In particular, January and February received 28% and 15%, respectively, of their normal monthly rainfall. When January and February are combined, January/ February 2013 is ranked as the driest of the period 1895–2014. Such large precipitation deficits exerted enormous stress on water resources in an already high water-demand region. Thus, it is of practical importance to investigate the causes of this extreme climate event so as to assess its predictability. *Chapter 3, Explaining Extreme Events of 2013 from a Climate Perspective, Bull. Amer. Meteor. Soc., 95 (9)

Center for Biological Diversity vs. Lincoln County Water District

Nevada Appellate Courts | January 25th, 2024

This case examines whether the State Engineer has the authority to redesignate multiple existing hydrographic basins as one "superbasin" based on a shared source of water

This case examines whether the State Engineer has the authority to redesignate multiple existing hydrographic basins as one "superbasin" based on a shared source of water for purposes of the water's administration and management. We also look at whether the State Engineer complied with due process in creating the superbasin at issue here.

Central Kings Groundwater Sustainability Agency Groundwater Sustainability Plan

Central Kings Groundwater Sustainability Agency (CKGSA) | December 11th, 2019

Central Kings Groundwater Sustainability Agency Groundwater Sustainability Plan (Revised)

Central Kings Groundwater Sustainability Agency (CKGSA) | July 13th, 2022

Central Valley Project (CVP) Water Transfer Program Fact Sheet

U.S. Bureau of Reclamation (USBR) | February 1st, 2015

Water transfers and exchanges are an integral part of CVP water operations, particularly in drought years, as long as transfers can occur consistent with stat

Water transfers and exchanges are an integral part of CVP water operations, particularly in drought years, as long as transfers can occur consistent with state and federal laws governing water transfers. In 2014, Reclamation facilitated the transfer of over 257,000 acre-feet of water. Of the 257,000 acre-feet, 213,220 acre-feet was considered “new water” to the system, meaning specific actions (such as reservoir reoperation, crop idling/shifting, groundwater substitution, or Yuba Accord purchases) were taken to make the water available. The remaining quantity was considered an in-basin transfer or a reallocation of contract supply. • §3405(a) of the Central Valley Project Improvement Act of 1992 (CVPIA) authorizes the transfer of all or a portion of a CVP contractors contracted water supply to any other California water user or water agency, State or Federal agency, Indian Tribe, or private non-profit organization for project purposes or any purpose recognized as beneficial under State law. • CVP water transfers are subject to the conditions prescribed in §3405(a), 1993 Interim Guidelines for Implementation of Water Transfers, and the Department of the Interior Final CVPIA Administrative Proposal on Water Transfers (1998). • Water transfer provisions of CVPIA do not apply to permanent contract assignments under which a CVP contractor relinquishes their contractual right to Project water; water banking and recharge actions outside of the contractors boundaries; water for water exchanges; forbearance actions whereby CVP contractors are paid not to exercise their right to water; and transfers of base supply water under settlement contracts which are carried out in accordance with State law. • Since 1992, the Region and the State of California Department of Water Resources, owners and operators of the two largest water projects in California, have collaborated to develop criteria to facilitate water transfers. • The Region facilitates both short and long-term transfers of CVP water. Long-term transfer approvals are accomplished through programmatic environmental documentation, with annual approvals of physical water transfers.

Changes in Winter Atmospheric Rivers along the North American West Coast in CMIP5 Climate Models

American Meteorological Society (AMS) | April 1st, 2014

Most extreme precipitation events that occur along the North American west coast are associated with winter atmospheric river (AR) events. Global climate models h

Most extreme precipitation events that occur along the North American west coast are associated with winter atmospheric river (AR) events. Global climate models have sufficient resolution to simulate synoptic features associated with AR events, such as high values of vertically integrated water vapor transport (IVT) approaching the coast. From phase 5 of the Coupled Model Intercomparison Project (CMIP5), 10 simulations are used to identify changes in ARs impacting the west coast of North America between historical (1970–99) and end-of-century (2070–99) runs, using representative concentration pathway (RCP) 8.5. The most extreme ARs are identified in both time periods by the 99th percentile of IVT days along a north–south transect offshore of the coast. Integrated water vapor (IWV) and IVT are predicted to increase, while lower- tropospheric winds change little. Winter mean precipitation along the west coast increases by 11%–18% [from 4% to 6% (8C)21], while precipitation on extreme IVT days increases by 15%–39% [from 5% to 19% (8C)21]. The frequency of IVT days above the historical 99th percentile threshold increases as much as 290% by the end of this century.