Review of Water Supply Reliability Estimation Related to the Sacramento-San Joaquin Delta

Delta Stewardship Council (Delta Council) | June 16th, 2022

RipZET: Documentation of Tool Demonstration in Marin County

San Francisco Estuary Institute (SFEI) | March 31st, 2015

The San Francisco Estuary Institute and Aquatic Science Center (SFEI‐ASC) has developed the Riparian Zone Estimation Tool (RipZET) to help the California community of

The San Francisco Estuary Institute and Aquatic Science Center (SFEI‐ASC) has developed the Riparian Zone Estimation Tool (RipZET) to help the California community of riparian interests visualize and characterize riparian areas as habitat unto themselves as well as their capacity to function as buffers for protecting the ecosystem services of the state’s streams, lakes and wetlands. RipZET is a tool used with Geographic Information System (GIS) and spreadsheet software to estimate “functional riparian width,” or the width associated with different riparian functions (e.g., large woody debris input, shading, floodwater storage), which varies with channel type and watershed location. The concept of functional riparian width is central to the riparian definition recommended by the National Research Council (NRC 2002) and is integral in many recently developed riparian design and management guidelines around the country.

Rising Seas and Electricity Infrastructure: Potential Impacts and Adaptation Actions for San Diego Gas & Electric

California Energy Commission (CEC) | August 31st, 2018

Part A: Rising sea levels pose a threat to California’s energy infrastructure and the coastal communities that it serves. To better understand this threat, this

Part A: Rising sea levels pose a threat to California’s energy infrastructure and the coastal communities that it serves. To better understand this threat, this study analyzed the exposure of San Diego Gas & Electric Company (SDG&E) electricity assets in San Diego County to climate change- driven coastal wave flooding, tidal inundation, and coastal erosion. The study found that the greatest potential direct impacts are damage to four substations in the Mission Bay and San Diego Bay areas. By modeling the potential costs to customers from unserved energy due to service disruptions driven by exposed substations, this study found economic impacts could— under an extreme sea level rise scenario in the late 21st century compounded by a 100 year storm-- range from $1.2 billion to $25 billion, assuming no adaptation actions are taken. Nearby communities could also experience indirect impacts if critical customers served by the substations—such as sewage pumping stations, hospitals, airports, and ports—are affected by outages. For other asset types, potential direct impacts are expected in the form of increased maintenance and repair costs. The research team identified a range of potential adaptation measures to build resilience to potential impacts. The application of flexible adaptation pathways emerged through the study as the best approach to improve implementation of these measures in the face of future uncertainty. Rather than selecting adaptation measures based only on what is known today, flexible adaptation pathways help establish information that that should be tracked, termed signposts, to help navigate uncertainty, set thresholds that trigger adaptation actions, and determine if an adaptation plan is meeting its objectives. Using these pathways, four initial climate adaptation actions were identified for SDG&E: 1) enhance coastal storm prediction and response, 2) identify signposts and thresholds that indicate when the need for an adaptation decision is approaching, 3) conduct consultations with regional stakeholders to identify opportunities to improve community-wide resilience, and 4) improve and fine-tune cost-benefit analysis methods to increase accuracy and confidence in cost-benefit estimates that incorporate climate change. Click here for Part B of the report, Potential Climate Change Impacts and Adaptation Actions for Gas Assets in the San Diego Gas and Electric Company Service Area, CEC, 2018

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).

Role of Science and Engineering in Decision-Making Within the State and Regional Water Boards

California State Water Resources Control Board (SWRCB) | December 16th, 2005

The primary purpose of State Water Resources Control Board and the nine Regional Water Quality Control Boards is to preserve and protect the beneficial uses of all waters

The primary purpose of State Water Resources Control Board and the nine Regional Water Quality Control Boards is to preserve and protect the beneficial uses of all waters of the State. This includes all ground water, more than 1.6 million acres of lakes, 211,000 miles of rivers and streams, more than 1.3 million acres of bays and estuaries, 1,609 miles of coastline, and the first three miles of ocean off of our coastline. The California legislature found that “activities and factors which may affect the quality of the waters of the State shall be regulated to attain the highest water quality that is reasonable . . . (and) that the state must protect the quality of waters in the state from degradation inside or outside the boundaries of the state.” How we use water, or expect to use water in the future determines its beneficial uses. A designated beneficial use determines the quality of water that must be maintained for that use. Protecting water quality and preventing degradation in order to preserve beneficial uses of water relies heavily on science and engineering. Protecting water quality also depends on an equitable system for allocating water resources, which is carried out by the State Water Resources Control Board’s water rights program. This report discusses the role of science and engineering (technology) in decision-making at the water boards in implementing federal and state laws along with their implementing regulations, and water board plans and policies.

Sacramento and San Joaquin Basins Climate Impact Assessment

U.S. Bureau of Reclamation (USBR) | September 8th, 2014

Through West-Wide Climate Risk Assessments (WWCRAs) conducted under that program, Reclamation is conducting reconnaissance-level assessments of risks to water supplies an

Through West-Wide Climate Risk Assessments (WWCRAs) conducted under that program, Reclamation is conducting reconnaissance-level assessments of risks to water supplies and related resources in eight major Reclamation river basins in the Western United States. This report presents the results of the Sacramento and San Joaquin Climate Impact Assessment (SSJIA), which addresses impacts in two of these major basins in California. The SSJIA also includes the Tulare Lake Basin in the southern part of the Central Valley of California; part of the Trinity River watershed from which some water is diverted into the Central Valley; and a portion of California’s central coast region where Central Valley Project (CVP) and State Water Project (SWP) water supplies are delivered. The water supplies and demands analyzed in the SSJIA include CVP water users, SWP water users, and the other non-project water users in the study area. Included in the report is an overview of the current climate and hydrology of California’s Central Valley (Sacramento, San Joaquin and Tulare Lake Basins), an analysis of observed trends in temperature and precipitation over historical record, and a comparison of these trends to future water operation projections not considering climate change. The report then presents hydrologic projections developed from global climate models to evaluate the ways that projected climatic and hydrologic changes could impact water availability and management and water demands within the Sacramento, San Joaquin and Tulare Lake basins. The SSJIA analyzes potential impacts of climate change under a current trends projection of future urban growth considering the conversion of agricultural to urban land use and assuming the continuation of current crop types in the Central Valley. Finally, the SSJIA assesses risks to the eight major resource categories identified in the SWA by looking at a range of climate futures and attempting to book-end future uncertainties.

Sacramento and San Joaquin Rivers Basin Study: Technical Report

U.S. Bureau of Reclamation (USBR) | March 8th, 2016

This Technical Report supplements the Sacramento and San Joaquin Basins Study Report (Summary Report) by providing greater detail on the technical approach employed in th

This Technical Report supplements the Sacramento and San Joaquin Basins Study Report (Summary Report) by providing greater detail on the technical approach employed in this analysis, including assumptions, methodologies and results not included in this Report. See the Summary Report for a discussion of the Basin Study program context (Section 1), basin settings (Section 2), and historic and projected climate (Section 2). Figure P-1 shows the geographic area included in the study. The Central Valley and regions that depend on the Sierra Nevada and Coast Range mountains for water have been facing rising demands for water from rapidly increasing populations, changes in land use, and growing urban, agricultural and environmental demands. These demands already exceed the capacity of the existing water management system to supply adequate water—especially in droughts like the one California is now experiencing. Future climate changes are likely to increase the challenges that have already occurred in the 20th century. This Basins Study builds on previous climate impact assessments and addresses both the potential impacts of climate and socioeconomic changes and explores how these challenges might be addressed (see Section 1. Introduction of the Summary Report).

Sacramento River Flood Control Project Weirs and Flood Relief Structures

California Department of Water Resources (DWR) | April 8th, 2011

Sacramento Valley has a history of floods and management of floods that goes back as long as people have populated the region. Prior to flood management, the valley floor

Sacramento Valley has a history of floods and management of floods that goes back as long as people have populated the region. Prior to flood management, the valley floor would be blanketed by seasonal runoff nearly every year; the Sacramento Valley was once nicknamed the “inland sea.” This tendency to flood results from the geography of the region as well as the weather. The occasionally large amounts of rain that fall in the surrounding Coastal ranges and the relatively steep Sierra Nevada mountain ranges produce rapid surface water runoff to the Sacramento River. The amount of this surface water runoff can be quite large, depending on the amount of rainfall, snow melt, and soil moisture of the watershed. Fast water flowing from the mountains is blunted by the relatively shallow grade of the Sacramento River south of the city of Red Bluff, and would often overtop the river banks. In addition, The Sacramento River would begin depositing sediment in the more shallow grades that would often alter its direction of flow. In order to control these storm flows that would otherwise flood farmland and cities, the Sacramento River Flood Control Project (the Project) was created. The Project was designed with the understanding that runoff from many of the storm events experienced in the Sacramento River watershed cannot be contained within the banks of the river. Nor could this flow be fully contained within a levee system without periodically flooding adjacent property. Thus, the Project was designed to occasionally spill through a system of weirs and flood relief structures into adjacent basins. These basins are designed to contain flood waters and channel them downstream, to eventually be conveyed back into the Sacramento River near Knights Landing and Rio Vista. Dry weather flows are contained within levees near the river banks and land within the flood basins is then used for agricultural purposes.

Sacramento River Hydrologic Region Groundwater Update

California Department of Water Resources (DWR) | April 1st, 2015

The primary goal of the Sacramento River Hydrologic Region (Sacramento River region) groundwater update is to expand information about region-specific groundwater conditi

The primary goal of the Sacramento River Hydrologic Region (Sacramento River region) groundwater update is to expand information about region-specific groundwater conditions for California Water Plan Update 2013 and to guide more informed groundwater management actions and policies. A second goal is to steadily improve the quality of groundwater information in future California Water Plan (CWP) updates to a level that will enable regional water management groups (RWMGs) to accurately evaluate their groundwater resources and implement management strategies that can meet local and regional water resource objectives within the context of broader statewide objectives. The final goal is to identify data gaps and groundwater management challenges that will serve as a guide to prioritizing future data collection and funding opportunities relevant to the region. This regional groundwater update is not intended to provide a comprehensive and detailed examination of local groundwater conditions, or a substitute for local studies and analysis. Nonetheless, where information is readily available, this update does report some aspects of regional groundwater conditions in greater detail.

Safeguarding California Plan: 2018 Update – California’s Climate Adaptation Strategy

California Natural Resources Agency (CNRA) | January 1st, 2018

Globally, California leads in efforts to avoid the worst effects of climate change by reducing greenhouse gas emissions. Still, the impacts of climate change a

Globally, California leads in efforts to avoid the worst effects of climate change by reducing greenhouse gas emissions. Still, the impacts of climate change are already being felt in California and are disproportionately impacting the state’s most vulnerable populations. The accelerating rate of climate change in this century will likely exceed that experienced by California’s native peoples over past millennia. Already these changes have rendered our state’s 117 years of weather-related record-keeping unreliable as predictors of future events. We know that California’s climate is changing, and responsible institutions must plan for and take action to address current and future climate impacts.