Los Angeles Waterkeeper v. State Water Resources Control Board

Second Appellate District, Court of Appeal of the State of California | February 27th, 2023

Los Osos Community Services District v. Golden State Water Company

Superior Court of California, County of San Luis Obispo | October 14th, 2015

This Stipulated Judgment concerns the Los Osos Groundwater Basin, as it is more particularly described in Sections 1.4.2 and 2.1 of this Stipulated Judgment, which underl

This Stipulated Judgment concerns the Los Osos Groundwater Basin, as it is more particularly described in Sections 1.4.2 and 2.1 of this Stipulated Judgment, which underlies the unincorporated communities of Los Osos, Baywood Park and Cuesta-by-the-Sea in San Luis Obispo County, California (“Basin”). The Basin is the only source of water for residential, commercial, institutional and agricul-tural development on properties overlying the Basin. This litigation (the “Action”) relates to efforts by the parties to sustainably manage the water resources of the Basin and to protect and promote the economic, environmental and social health of the community.

Los Osos Valley Groundwater Basin Fringe Areas Characterization

San Luis Obispo County Flood Control and Water Conservation District | May 22nd, 2018

The Sustainable Groundwater Management Act (SGMA) took effect on January 1, 2015, and requires that certain actions be taken in groundwater basins designated as either hi

The Sustainable Groundwater Management Act (SGMA) took effect on January 1, 2015, and requires that certain actions be taken in groundwater basins designated as either high or medium priority by the California Department of Water Resources (DWR), including Los Osos Basin. DWR identified the Los Osos Basin as a high priority basin subject to critical conditions of overdraft due to seawater intrusion and nitrate impairment (DWR, 2014, 2016). SGMA does not apply to the Los Osos Basin area that is at issue in Los Osos Community Services District v. Southern California Water Company [Golden State Water Company], et al.1 (Adjudicated Plan Area), for which a Stipulated Judgment was approved in San Luis Obispo Superior Court on October 14, 2015. The boundaries of the Adjudicated Plan Area do not coincide with the Basin boundaries as documented in DWR’s Interim Update to Bulletin 118 (2016). The groundwater basin areas between the Bulletin 118 Basin boundaries (Basin 3‐8) and the Adjudicated Plan Area boundary are referred to as “Fringe Areas” (Figure 1). In order to comply with SGMA, the County of San Luis Obispo (County) formed the Groundwater Sustainability Agency (GSA) over these Fringe Areas on April 4, 2017. The results of this basin characterization study are intended to produce a basis of knowledge for use in boundary modification requests and potential future use in development of a Groundwater Sustainability Plan (GSP). Decades of technical studies on the basin have focused primarily on aquifers within the Adjudicated Plan Area. This technical memorandum supplements prior work, which together provide a comprehensive hydrogeologic characterization and conceptual model of the Fringe Areas.

Losses of Sacramento River Chinook Salmon and Delta Smelt to Entrainment in Water Diversions in the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | June 30th, 2008

Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of

Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of salvage counts with population indices have failed to provide quantitative estimates of the magnitude of this mortality. I estimated the proportional losses of Sacramento River Chinook salmon (Oncorhynchus tshawytscha) and delta smelt (Hypomesus transpacificus) to place these losses in a population context. The estimate for salmon was based on recoveries of tagged smolts released in the upper Sacramento River basin, and recovered at the fish-salvage facilities in the south Delta and in a trawling program in the western Delta. The proportion of fish salvaged increased with export flow, with a mean value around 10% at the highest export flows recorded. Mortality was around 10% if pre-salvage losses were about 80%, but this value is nearly unconstrained. Losses of adult delta smelt in winter and young delta smelt in spring were estimated from salvage data (adults) corrected for estimated pre-salvage survival, or from trawl data in the southern Delta (young). These losses were divided by population size and accumulated over the respective seasons. Losses of adult delta smelt were 1–50% (median 15%) although the highest value may have been biased upward. Daily losses of larvae and juveniles were 0–8%, and seasonal losses accumulated were 0–25% (median 13%). The effect of these losses on population abundance was obscured by subsequent 50-fold variability in survival from summer to fall.

Lower Basin Alternative for the Post-2026 Coordinated Operation of the Colorado River Basin

Southern Nevada Water Authority (SNWA) | March 6th, 2024

Lower Colorado River Basin Plan letter to the U.S. Bureau of Reclamation, 5/22/23

U.S. Bureau of Reclamation (USBR) | May 22nd, 2023

Lower Colorado River Mainstream Evaporation and Riparian Evapotranspiration Losses Report

U.S. Department of the Interior (DOI) | February 8th, 2024

On August 16, 2022, the Bureau of Reclamation (Reclamation) and Department of the Interior announced several administrative actions for consideration to improve and prote

On August 16, 2022, the Bureau of Reclamation (Reclamation) and Department of the Interior announced several administrative actions for consideration to improve and protect the long-term sustainability of the Colorado River System. The System is currently experiencing prolonged drought and low runoff conditions accelerated by climate change that have led to historically low water levels in Lakes Powell and Mead (Reclamation, 2021). One of the actions included reviewing and prioritizing additional administrative initiatives to address system losses in the lower Colorado River mainstream. As part of that action, this report provides an overview of historical mainstream evaporation and riparian evapotranspiration (ET) losses along the lower Colorado River and presents methodologies used to develop those datasets. This report does not make recommendations on how to account for system losses in the lower Colorado River mainstream. Supplemental documents: Appendix 1 – Reaches Identified in the Lower Colorado River Mainstream Evaporation and Riparian Evapotranspiration Losses Report Appendix 2 – LCRAS Open Water Monthly Evaporative Losses Appendix 3 – Lake Mead, Lake Mohave, and Lake Havasu Evaporation from Reclamation’s Hydrologic Database (HDB) Appendix 4 – LCRAS Riparian Monthly Evapotranspiration Losses by Vegetation Appendix 5 – Evaporation and Riparian Evapotranspiration (ET) Coefficients Appendix 6 – Evaporation and Riparian Evapotranspiration (ET) Rates

Lower Mill Creek Watershed Conjunctive Use Project: Tehama County, California

California Department of Water Resources (DWR) | November 18th, 2008

In 1920, the Tehama County Superior Court of the State of California adjudicated entitlements to all Mill Creek flow below 203 cubic feet per second (cfs). As such, water

In 1920, the Tehama County Superior Court of the State of California adjudicated entitlements to all Mill Creek flow below 203 cubic feet per second (cfs). As such, water right holders on Mill Creek legally divert a significant portion of the surface water flow for agricultural beneficial use. During certain times of the year, especially during dry or critically dry years, the agricultural demand for surface water can reduce Mill Creek flow and expose in-stream barriers to fish migration. Fishery experts recognize Mill Creek as a high priority stream for the protection and enhancement of Chinook salmon spawning habitat. Mill Creek surface water diverters currently participate in a long-term cooperative management plan to help provide sufficient flow for fish migration while also maintaining irrigation supplies and the recognition of surface water rights. As part of these efforts, Mill Creek water users participate in water lease and groundwater exchange programs designed to increase in-stream flow during critical spring and fall fish migration periods. Along with other entities, the Department of Water Resources (DWR) plans to establish methods of monitoring and studying fish passage, assessing agricultural water use efficiency, and examining the potential for additional use of groundwater as opposed to use of surface water diversions in the Lower Mill Creek watershed. This report provides a background of the geology and hydrogeology in the Lower Mill Creek watershed area, a detailed discussion of the groundwater resources, and an overview of the potential for conjunctive use of surface water and groundwater resources. It also provides recommendations for additional groundwater monitoring and potentially favorable locations for production well installation associated with possible future conjunctive use programs.

Lower Peninsula Watershed Condition Assessment 2016: Southwest San Francisco Bay, Santa Clara County, San Francisquito to Stevens Creeks. Technical memorandum prepared for the Santa Clara Valley Water District

San Francisco Estuary Institute (SFEI) | October 2nd, 2017

This report describes baseline information about the amount and distribution of aquatic resources, and evaluates that overall ecological conditions of streams using the C

This report describes baseline information about the amount and distribution of aquatic resources, and evaluates that overall ecological conditions of streams using the California Rapid Assessment Method (CRAM), for the Lower Peninsula watershed in Santa Clara County; consisting of Stevens-Permanente Creek, Adobe Creek, southern extent of San Francisquito Creek, and their tributaries. The Lower Peninsula watershed covers approximately 98 square-miles with creeks flowing from the Santa Cruz Mountains into southwest San Francisco Bay and its tidal wetlands.  The Santa Clara Valley Water District’s (District) Safe, Clean Water and Natural Flood Protection Program has many priorities, including Priority D for restoring and protecting vital wildlife habitat, and providing opportunities for increased access to trails and open space. The D5 Project focuses on ecological data collection and analysis at a watershed scale to support the District, other County agencies and organizations in making informed ecological asset management decisions. The key performance indicators (KPIs) for D5 are to:  1. Establish new or track existing ecological levels of service for streams in 5 watersheds.  2. Reassess streams in 5 watersheds to determine if ecological levels of service are maintained or improved. 

Lower Peninsula Watershed Condition Assessment 2016. Technical memorandum prepared for the Santa Clara Valley Water District - Priority D5 Project

San Francisco Estuary Institute (SFEI) | October 2nd, 2017

This report describes baseline information about the amount and distribution of aquatic resources, and evaluates that overall ecological conditions of streams using the C

This report describes baseline information about the amount and distribution of aquatic resources, and evaluates that overall ecological conditions of streams using the California Rapid Assessment Method (CRAM), for the Lower Peninsula watershed in Santa Clara County; consisting of Stevens-Permanente Creek, Adobe Creek, southern extent of San Francisquito Creek, and their tributaries. The Lower Peninsula watershed covers approximately 98 square-miles with creeks flowing from the Santa Cruz Mountains into southwest San Francisco Bay and its tidal wetlands.