Ridging associated with drought in western and southwestern United States: characteristics, trends and predictability

American Meteorological Society (AMS) | April 1st, 2020

Persistent winter ridging events are a consistent feature of meteorological drought across the western and southwestern United States. In this study, a ridge detection al

Persistent winter ridging events are a consistent feature of meteorological drought across the western and southwestern United States. In this study, a ridge detection algorithm is developed and applied on daily geopotential height anomalies to track and quantify the diversity of individual ridge characteristics (e.g., position, frequency, magnitude, extent, and persistence). Three dominant ridge types are shown to play important, but differing, roles for influencing the location of landfalling atmospheric rivers (ARs), precipitation, and subsequently meteorological drought. For California, a combination of these ridge types is important for influencing precipitation deficits on daily through seasonal time scales, indicating the various pathways by which ridging can induce drought. Furthermore, both the frequency of ridge types and reduced AR activity are necessary features for explaining drought variability on seasonal time scales across the western and southwestern regions. The three ridge types are found to be associated in different ways with various remote drivers and modes of variability, highlighting possible sources of subseasonal-to-seasonal (S2S) predictability. A comparison between ridge types shows that anomalously large and persistent ridging events relate to different Rossby wave trains across the Pacific with different preferential upstream locations of tropical heating. For the “South-ridge” type, centered over the Southwest, a positive trend is found in both the frequency and persistence of these events across recent decades, likely contributing to observed regional drying. These results illustrate the utility of feature tracking for characterizing a wider range of ridging features that collectively influence precipitation deficits and drought.

Risk-Informed Future Climate Scenario Development for the State Water Project Delivery Capability Report

California Department of Water Resources (DWR) | August 24th, 2023

This report introduces and documents an extensive effort undertaken by the California Department of Water Resources (DWR) to develop risk-informed future climate scenario

This report introduces and documents an extensive effort undertaken by the California Department of Water Resources (DWR) to develop risk-informed future climate scenarios for the State Water Project (SWP) Delivery Capability Report (DCR), a report issued by the SWP every two years. These reports present DWR’s analysis of the SWP system and planning information for users of SWP water. The analysis provides information about how climate change, regulatory, and operational considerations affect SWP delivery capability. Specifically, the report must provide “…under a range of hydrologic conditions, the then existing overall delivery capability of the project facilities and the allocation of that capacity to each contractor. The range of hydrologic conditions shall include the historic extended dry cycle and long-term average.” (Settlement Agreement 2003).

Root Creek Water District Groundwater Sustainability Agency Groundwater Sustainability Plan

Root Creek Water District | November 11th, 2019

Root Creek Water District Groundwater Sustainability Plan

Root Creek Water District | March 20th, 2023

Safe Clean Water Water for Los Angeles County Residents

Los Angeles County Department of Public Works (LACDPW) | November 7th, 2017

We live in a water-scarce area, and forces outside of our control can threaten our local water resources, including lakes, rivers and beaches. LA Count

We live in a water-scarce area, and forces outside of our control can threaten our local water resources, including lakes, rivers and beaches. LA County residents rely heavily on imported water from the Sierra Mountains, the Central Valley and even from states as far away as Colorado. Climate change is causing more and more extreme weather conditions, making these remote sources more unreliable . The impacts of the recent five-year drought were widely felt here. Rainfall is an essential, local source of LA’s water . Rain runs through local rivers, creeks and streams and can be absorbed underground, replenishing groundwater, which is a local source of drinking water. However, because so much of our region is paved over, when we do experience heavy rain, too much of that precious water is lost to the ocean before we can capture it for use. Our local water resources are also threatened by toxins and pollution as stormwater runs through streets and over-paved areas into our rivers, creeks and streams. Pollution flows onto our beaches and into the ocean, posing a public health risk and harming marine life.

Salinas River Watershed Area Salt Modeling

California Central Coast Regional Water Quality Control Board (CCRWQCB) | November 13th, 2015

Tetra Tech supported EPA Region 9 and the Central Coast Regional Water Quality Control Board (CCRWQCB) for an assessment of salt impairments and development of a

Tetra Tech supported EPA Region 9 and the Central Coast Regional Water Quality Control Board (CCRWQCB) for an assessment of salt impairments and development of a salt mass balance in the Lower Salinas River and Reclamation Canal watersheds. This effort can inform development of salt-related TMDLs by the CCRWQCB and a salt and nutrient management plan for the Salinas Valley aquifers. Three reaches have reported 2010 303(d) listings for salt-related impairments in these watersheds including impairments due to chloride, sodium, electrical conductivity, and total dissolved solids – Lower Salinas River, Santa Rita Creek, and Alisal Creek. This report provides data analysis and a literature review (Sections 1 through 5), development of a water and salt mass balance tool (Sections 6 through 8), and salt source assessment (Section 9). The results of the analysis provide a strong foundation for assessing salt sources and understanding salt mass balance in the study area, but can be improved with refined representation of cropland locations, rotations, and irrigation practices.

Salinas Valley Groundwater Basin 180/400-Foot Aquifer Subbasin Groundwater Sustainability Plan

Salinas Valley Basin Groundwater Sustainability Agency | January 3rd, 2020

The 2014 California Sustainable Groundwater Management Act (SGMA) requires that medium and high-priority groundwater basins and subbasins develop Groundwater Sustainabil

The 2014 California Sustainable Groundwater Management Act (SGMA) requires that medium and high-priority groundwater basins and subbasins develop Groundwater Sustainability Plans (GSPs) that outline how they will achieve groundwater sustainably in 20 years, and maintain sustainability for an additional 30 years. This GSP fulfills that requirement for the Salinas Valley-180/400-Foot Aquifer Subbasin. In 2017, local GSA-eligible entities formed the Salinas Valley Basin Groundwater Sustainability Agency (SVBGSA) to develop and implement the GSPs for the Salinas Valley. The SVBGSA is a Joint Powers Authority (JPA) with membership comprising the County of Monterey, Water Resources Agency of the County of Monterey (Monterey County Water Resources Agency, or MCWRA), City of Salinas, City of Soledad, City of Gonzales, City of King, Castroville Community Services District, and Monterey One Water. The SVBGSA is governed by an eleven-member Board of Directors, representing public and private groundwater interests throughout the Salinas Valley Groundwater Basin. In addition, an Advisory Committee ensures participation by, and input to, the Board by constituencies whose interests are not directly represented on the Board. The SVBGSA’s activities are coordinated by a General Manager. The Salinas Valley Groundwater Basin consists of nine subbasins, of which six fall entirely or partially under the SVBGSA’s jurisdiction. One of the nine subbasins, the Seaside Subbasin, is adjudicated and not managed by the SVBGSA. Another two subbasins, the Paso Robles and Atascadero Subbasins, lie completely in San Luis Obispo County and are managed by other groundwater sustainability agencies. The SVBGSA developed this GSP in coordination with the Marina Coast Water District Groundwater Sustainability Agency (MCWD GSA) and the County of Monterey Ground Water Sustainability Agency (County GSA). The SVBGSA developed this GSP for the 180/400-Foot Aquifer Subbasin (Subbasin) in concert with the GSPs for its five other Salinas Valley Subbasins: the Eastside Aquifer Subbasin (DWR subbasin number 3-004.02), the Forebay Aquifer Subbasin (DWR subbasin number 3-004.04), the Upper Valley Aquifer Subbasin (DWR subbasin number 3-004.05), the Langley Area Subbasin (DWR subbasin number 3-004.09) and the Monterey Subbasin (DWR subbasin number 3-004.10). Together, the six subbasin plans under the SVBGSA will be integrated into the Salinas Valley Integrated Groundwater Sustainability Plan. This GSP covers all of the 89,700 acres of the 180/400-Foot Aquifer Subbasin, as shown in Figure 1.The GSP describes current groundwater conditions, develops a hydrogeologic conceptual model, establishes a water budget, outlines local sustainable management criteria, and provides projects and programs for reaching sustainability in the Subbasin by 2040. A downloaded copy of the GSP is available below, which has been divided into 8 sections. Or the "Get Document" link will lead readers to the online version lodged at the California Department of Water Resources SGMA Portal. Part 1  Part 2 Part 3 Part 4 Part 5 Part 6 Part 7 Part 8 Part 9

Salinas Valley Groundwater Basin Monterey Subbasin Groundwater Sustainability Plan

Salinas Valley Basin Groundwater Sustainability Agency | January 28th, 2022

On September 16, 2014, the California legislature enacted the Sustainable Groundwater Management Act (SGMA) whose primary purpose is to achieve and/or maintain sustainabi

On September 16, 2014, the California legislature enacted the Sustainable Groundwater Management Act (SGMA) whose primary purpose is to achieve and/or maintain sustainability within the state’s high and medium priority groundwater basins. Key tenets of SGMA are the concept of local control, use of best available data and science, and active engagement and consideration of all beneficial uses and users of groundwater. As such, SGMA empowers certain local agencies to form Groundwater Sustainability Agencies (GSAs) whose purpose is to manage basins sustainably through the development and implementation of Groundwater Sustainability Plans (GSPs). Under SGMA, GSPs are required to contain certain elements, the most significant of which include: a Sustainability Goal; a description of the area covered by the GSP (“Plan Area”); a description of the Basin Setting, including the hydrogeologic conceptual model, historical and current groundwater conditions, and a water budget; locally-defined sustainability criteria; networks and protocols for monitoring sustainability indicators; and a description of projects and/or management actions that will be implemented to achieve or maintain sustainability. SGMA also requires a significant element of stakeholder outreach to ensure that beneficial uses and users of groundwater are given the opportunity to provide input into the GSP development and implementation process. This GSP covers the entire Monterey Subbasin (Department of Water Resources [DWR] Basin 3-004.10), which encompasses 30,850 acres (or 48.2 square miles) in the northwestern Salinas Valley Groundwater Basin in the Central Coast region of California (Figure ES-1). The Monterey Subbasin (Subbasin) has been designated by the California Department of Water Resources (DWR) as medium priority. As such, the Subbasin is required to develop a GSP by January 2022 and achieve sustainability by 2042. The GSP has been co-developed by the Marina Coast Water District Groundwater Sustainability Agency (MCWD GSA) and the Salinas Valley Basin Groundwater Sustainability Agency (SVBGSA) pursuant to a Framework Agreement. The Framework Agreement outlines the Management Areas to be established within the Subbasin, which are later formalized in this GSP. The Framework Agreement further establishes a basis for information developed by the two agencies to be integrated into a single GSP for the Monterey Subbasin. Plan approved by DWR 4/27/23.

San Diego Basin Study

U.S. Bureau of Reclamation (USBR) | August 15th, 2017

The purpose of the San Diego Basin Study (Basin Study) is to determine potential climate change impacts on water supplies and demands within the San Diego region and to i

The purpose of the San Diego Basin Study (Basin Study) is to determine potential climate change impacts on water supplies and demands within the San Diego region and to identify how potential adaptation strategies could mitigate supply shortages. The intention of Task 2.3 is to create a computer simulation model to forecast supply and demand imbalances under current and future conditions, and current and future demands under a baseline water system infrastructure in the Study Area. This Interim Report describes the methodologies and findings of this Task. 

Santa Ana Watershed Basin Study

U.S. Bureau of Reclamation (USBR) | September 1st, 2013

The U.S. Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) program allows all bureaus of the Department to collaboratively

The U.S. Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) program allows all bureaus of the Department to collaboratively work with States, Tribes, local governments, and non-governmental organizations to pursue a sustainable water supply for the Nation. This is done through a framework that provides federal leadership and assistance on the efficient use of water, and by integrating water and energy policies to support the sustainable use of all natural resources. Basin Studies, one of the tools of this program, are basin-wide efforts to evaluate and address the impacts of climate change, and define options for meeting future water demands in river basins in the western United States where imbalances in water supply and demand exist or are projected. The Bureau of Reclamation (Reclamation) and the Santa Ana Watershed Project Authority (SAWPA) partnered in the WaterSMART Santa Ana Watershed Basin Study (Study). The work done under the Study was used to help SAWPA update its One Water One Watershed (OWOW) Plan. OWOW is an Integrated Regional Water Management Plan (IRWMP) for the Santa Ana River Watershed (SARW) that serves as the blueprint for SAWPA, its member agencies and key stakeholders to effectively manage water resources over the next 30 years. The Santa Ana Watershed Basin Study illustrates how effective collaboration can improve water management. This Study takes a crest-to-coast and corner-to-corner approach throughout a 2,400-square-mile watershed, which encompasses everything from beach to mountain communities, to address the area’s unique water resource challenges. The SARW is home to more than 6 million people, and tens of millions more people visit the area each year. The region also has a large manufacturing, industrial, and agricultural base. More than 350 water, wastewater, and groundwater management, flood control, environmental and other non-governmental organizations, are working together as partners with SAWPA on the OWOW Plan. Through the Basin Study Program, Reclamation is partnering with SAWPA and its stakeholders to update key components of the Plan, now known as OWOW 2.0.