State of California Sea Level Guidance

California Ocean Protection Council (COPC) | May 31st, 2024

This report updates and replaces the previous 2018 ‘State of California Sea Level Rise Guidance’ and marks the fourth iteration of statewide guidance since 2010 for s

This report updates and replaces the previous 2018 ‘State of California Sea Level Rise Guidance’ and marks the fourth iteration of statewide guidance since 2010 for state and local decision-makers to incorporate best available science on sea level rise into planning, design, permitting, investments, and other decisions.

State of California Sea Level Rise Guidance

California Natural Resources Agency (CNRA) | March 14th, 2018

The climate across California is changing, and the effects, such as rising average temperatures, shrinking mountain snowpack, more intense storms, and higher sea

The climate across California is changing, and the effects, such as rising average temperatures, shrinking mountain snowpack, more intense storms, and higher sea levels are expected to continue and worsen in the coming decades. Sea-level rise is caused by the thermal expansion of warming ocean water and melting of land ice as the Earth warms. It is one of the most obvious manifestations of the trend of climate change and is an immediate and real threat to lives, livelihoods, transportation, economies, and the environment in California. In April 2017, catalyzed by direction from Governor Brown and the need to ensure that best available science was informing sea-level rise planning decisions in California, a Working Group of the California Ocean Protection Council’s Science Advisory Team (OPC-SAT) released a report, entitled “Rising Seas in California: An Update on Sea-Level Rise.” The Rising Seas Report was prepared and peer-reviewed by some of the nation’s foremost experts in coastal processes, climate and sea-level rise science, observational and modeling science, the science of extremes, and decision-making under uncertainty. The report synthesized the current state of sea-level rise science, including advances in modeling and improved understanding of the processes that could drive extreme global sea-level rise as a result of ice loss from the Greenland and Antarctic ice sheets. The report found that: Scientific understanding of sea-level rise is advancing at a rapid pace. The direction of sea-level change is clear; sea levels are rising. The rate of ice loss from the Greenland and Antarctic ice sheets is increasing, and California is particularly vulnerable to sea-level rise caused by ice loss from West Antarctica. New scientific evidence has highlighted the potential for extreme sea-level rise. Probabilities of specific sea-level increases can inform decisions. Current policy decisions are shaping our coastal future. Waiting for scientific certainty is neither a safe nor prudent option. The increased understanding of sea-level rise projections and polar ice sheet loss warranted an update to the State’s sea-level rise guidance document to ensure decisions were based on the best available science. Additionally, an increased policy focus requiring state and local governments to incorporate climate change into decision making merited an update to address the needs of both state and local audiences. This updated document, the “State of California Sea-Level Rise Guidance” (Guidance), provides a bold, science-based methodology for state and local governments to analyze and assess the risks associated with sea-level rise, and to incorporate sea-level rise into their planning, permitting, and investment decisions. This Guidance provides: 1. A synthesis of the best available science on sea- level rise projections and rates for California; 2. A step-by-step approach for state agencies and local governments to evaluate those projections and related hazard information in decision making; and 3. Preferred coastal adaptation approaches.

State of California Sea-Level Rise Guidance—2018 Update

Ocean Protection Council (OPC) | March 4th, 2018

This updated document, the “State of California Sea-Level Rise Guidance” (Guidance), provides a bold, science-based methodology for state and local governments to ana

This updated document, the “State of California Sea-Level Rise Guidance” (Guidance), provides a bold, science-based methodology for state and local governments to analyze and assess the risks associated with sea-level rise, and to incorporate sea-level rise into their planning, permitting, and investment decisions. This Guidance provides:  A synthesis of the best available science on sea-level rise projections and rates for California;  A step-by-step approach for state agencies and local governments to evaluate those projections and related hazard information in decision making; and  Preferred coastal adaptation approaches. 

State of the Estuary 2019 Update

San Francisco Estuary Partnership (SFEP) | October 22nd, 2019

The San Francisco Estuary is a large and diverse system. Hundreds of miles of coastline stretch from the wide valleys of the Sacramento and San Joaquin Rivers to the stee

The San Francisco Estuary is a large and diverse system. Hundreds of miles of coastline stretch from the wide valleys of the Sacramento and San Joaquin Rivers to the steep headlands of the Golden Gate, with vast agricultural fields in the Delta and urbanized shorelines in Silicon Valley and many of the region’s cities. The complexity and scale of this system means it can take years to detect and assess changes. This interim State of the Estuary Report checks in on a few indicators of health and explores where the assessment should head over time. In the four years since the 2015 State of the Estuary Report, two issues have emerged as critical to how we assess the health of the estuarine ecosystem at the heart of the Bay Area and the Delta. First, the health of the Estuary and of the people who live near it and depend on it are inextricably linked. We need a healthy Bay and Delta to protect our shorelines from sea level rise, help keep our waters clean, provide food and habitat for fish and wildlife, and give people a place to enjoy nature. We also need to think more about human communities as we assess the health of natural communities. This focus means addressing environmental injustices that are deeply embedded in our culture and patterns of development. The second critical issue to emerge is the need for a greater focus on landscape resilience—how well the Bay and the Delta are equipped to respond to change—so that people and wildlife can thrive as climate change progresses. Taking these two ideas together, this report focuses on the nexus of social and ecological resilience as we look toward the future. The first section of the Report updates indicators of ecological health that span the entire extent of the San Francisco Estuary (Bay and Delta). Recent data show continued progress along the trajectories of the past decade. Tidal marsh restoration is proceeding at a brisk pace in the Bay and gaining traction in the Delta, while urban water conservation continues to meet mandated benchmarks, even during the drought. On the other hand, flows through the Estuary and across its floodplains continue to be well below levels that could increase and restore ecosystem health. Freshwater flows are a lynchpin of ecosystem processes that sustain physical habitats, fuel the food web, and regulate water quality. Creative approaches to using and re-using fresh water for environmental purposes are needed. Long-term trend analysis shows that fish communities in the Bay are declining. This analysis scores an index of 10 attributes of a healthy fish community. The index focuses on fish in offshore areas, and may not capture benefits to fish from near-shore wetland restoration projects. Despite this slow decline, fish communities in the saltier parts of the Estuary remain in good condition, while those in the brackish and freshwater areas are in poor condition. The next section of the report discusses three emerging indicators of Estuary health, offering options for how to assess resilience in future reports. Here, for the first time, the resilience of the Estuary’s shores is evaluated through the lens of subsidence and nature-based features. Elevation relative to sea level is a basic currency that must be tracked as the Pacific Ocean rises into the Estuary. The potential for the Estuary shore to be resilient to climate change and continue to provide benefits to people is related to how much of the shore zone is nature-based. The final emerging indicator, urban green space, is a first attempt to assess how access to nature is distributed across more and less advantaged communities. More work is needed to finalize all these emerging indicators before they can be included in any future quantitative assessment of the State of the Estuary. These emerging and updated indicators will help focus efforts to restore the Estuary’s health. In addition to continuing the successful aspects of restoration and conservation that this report describes, we need more investment in creative ways to use and restore flows for environmental health, to expand and build resilient shorelines and to weave considerations of social equity more strongly into efforts to improve environmental health. - J. Letitia Grenier, Lead Scientist

State of the Estuary, October 2013

San Francisco Estuary Partnership (SFEP) | October 31st, 2013

State of the Salinas River Groundwater Basin

Monterey County Water Resources Agency (MCWRA) | January 16th, 2015

From 6.3 Steps Appropriate to Address Water Supply under Continued Drought Conditions:  Based on the continued large storage declines in the East Side and Pressure Su

From 6.3 Steps Appropriate to Address Water Supply under Continued Drought Conditions:  Based on the continued large storage declines in the East Side and Pressure Subareas (and resulting groundwater head declines and seawater intrusion), the current distribution of groundwater extractions is not sustainable. Seawater intrusion can account for up to 18,000 afy of the total storage loss of up to 24,000 afy. Sustainable use of groundwater can only be achieved by aggressive and cooperative water resources management. The consequences of no-action under continued drought conditions will be the imminent advancement of seawater intrusion within the next few years and the continued decline of groundwater head. Both of these conditions would necessitate the drilling of deeper groundwater wells, which may not be feasible in some areas because of lower groundwater yield and water quality in the Pressure Deep Aquifer. A more sustainable long-term management practice would encourage the Basin-wide redistribution and reduction of groundwater pumping, which would require cooperative and aggressive resource management. The unsustainability of the current distribution of groundwater extractions has long been recognized by various investigators, and a Basin-wide redistribution and reduction in pumping has been recommended previously (e.g. DWR, 1946). 6.3.1 Technical Option 1:  The large storage declines that have occurred in the Basin in the past, especially in the East Side Subarea, have created a significant landward groundwater head gradient that must be reversed before seawater intrusion can be halted. Reduction of pumping in the Pressure and East Side Subareas could help mitigate some of the anticipated effects of extended drought on groundwater storage and water quality in the study area. Shifting of pumping to areas further away from the coast would also be helpful, as long as it is shifted south of the current head trough (Figure ES3) that exists in the East Side Subarea. One of the main reasons that substantial steps must be taken to curtail seawater intrusion is that the large storage declines that have occurred in the Basin in the past (especially in the East Side Subarea) have created a significant landward groundwater head gradient that must be reversed before seawater intrusion can be halted. 6.3.2 Technical Option 2: The shifting of some pumping from the P-180 and P-400 Aquifers to the Pressure Deep Aquifer would reduce the storage deficit in the shallower aquifers; however, this would necessarily lead to head declines in the Pressure Deep Aquifer. Unlike the P-180 and P-400 Aquifers, it is not known whether or not the Pressure Deep Aquifer is hydraulically connected to the ocean in Monterey Bay, so it is not known whether this pumping shift would lead to the onset of regional seawater intrusion. Also unknown is the likelihood of localized interaquifer seawater mixing between the Pressure 400- Foot Aquifer and the Pressure Deep Aquifer. Hence, this Management Option requires more investigation to determine its feasibility. 6.3.3 Evaluation of Potential Solutions: The numerical modeling analysis to be performed as a second part of this Basin Investigation will consider the effects of various management decisions on the water supply and water quality in the study area. The primary questions to be assessed for each scenario are: 1) what will be the rate of groundwater head decline; and, 2) what will be the rate of increase in acreage with impaired water quality due to the advancement of the seawater intrusion front. We can then assess the economic effects of 1) and 2) due to water supply wells becoming inoperable (i.e. dry), and the further loss of aquifer storage capacity due to the advancement of seawater intrusion. The numerical model should be used to predict groundwater head declines under different management scenarios, including implementing targeted pumping rates and optimizing the distribution of pumping. Future declines in groundwater head must be evaluated by simulated groundwater conditions so that “trigger (groundwater) head levels” can be used as a measure of safe yield and an early alert system as part of Basin Management Objectives. That analysis will extend the discussions and conclusions presented in this report.

State of the Salmonids: Status of California’s Emblematic Fishes 2017

University of California, Davis (UC Davis) | August 1st, 2017

California has, or had, 32 distinct kinds of salmonid fishes. They are either endemic to California or at the southern end of their ranges. Most are in serious decline:

California has, or had, 32 distinct kinds of salmonid fishes. They are either endemic to California or at the southern end of their ranges. Most are in serious decline: 45% and 74% of all salmonids will likely become extirpated from California in the next 50 and 100 years, respectively, if present trends continue. Our results suggest that California will lose more than half (52%) of its native anadromous salmonids and nearly a third (30%) of its inland taxa in just 50 years under current conditions. Climate change is a major overarching threat driving population declines throughout California and strongly affects the status of 84% of all salmonids reviewed. In addition, dams, agricultural operations, estuary alteration, non-native species, production hatcheries, and myriad other human-induced threats have contributed to declines. 81% of salmonids in California are now worse off than they were in 2007, when the previous version of this report was prepared. The changes in species status are the result of the 2012-2016 historic drought, improved data collection and review, and an improved understanding of climate change impacts. Returning these iconic species to sustainable levels requires access to productive and diverse habitats which promote the full range of life history diversity necessary to weather change. We recommend (i) protecting and investing in fully functioning watersheds such as the Smith River and Blue Creek, (ii) protecting and restoring source waters such as Sierra meadow systems, groundwater, and springs so that the impacts of climate change are reduced, (iii) restoring function and access to once productive and diverse habitats such as Central Valley floodplains, coastal lagoons, and estuaries, (iv) adopting reconciliation ecology as a basis for management in human dominated landscapes, (v) improving habitat connectivity and passage to historical spawning and rearing habitat, and (vi) improving salmonid genetic management throughout California.

State of the Salton Sea: A Science and Monitoring Meeting of Scientists for the Salton Sea

U.S. Geological Survey (USGS) | January 19th, 2017

The Salton Sea (Sea) is an ecosystem facing large systemic changes in the near future. Managers and stakeholders are seeking solutions to the decline of the Sea and have

The Salton Sea (Sea) is an ecosystem facing large systemic changes in the near future. Managers and stakeholders are seeking solutions to the decline of the Sea and have turned to the scientific community for answers. In response, scientists gathered in Irvine, California, to review existing science and propose scientific studies and monitoring needs required for understanding how to retain the Sea as a functional ecosystem. This document summarizes the proceedings of this gathering of approximately 50 scientists at a September 8–10, 2014, workshop on the State of the Salton Sea (SoSS).  In 1997, a similar gathering of nearly 100 scientists and others in Palm Springs, Calif., yielded a number of scientific proposals establishing a foundation for a program of integrated science investigations. The 1997 workshop results were combined with recommendations from a U.S. Geological Survey (USGS) Tiger Team (Shipley and others, 1999), resulting in the eventual creation of a Strategic Science Plan (SSP) for the Salton Sea (Salton Sea Science Subcommittee, 2000). The vision from the 1997 workshop of an integrated and coordinated program of scientific investigations, embraced by the SSP, was implemented through the SSC and the USGS Salton Sea Science Office (Science Office). The integrated science program, mandated by the Salton Sea Reclamation Act of 1998 (Public Law 105–372) and spelled out in the SSP, directly led to an increased scientific understanding of the Salton Sea ecosystem. The workshop concluded that “rehabilitation of the Sea is essential and requires that current ills be rectified in a manner that allows the Sea to sustain social values of importance to the human populations of the Imperial and Coachella Valleys, as well as society in general” (U.S. Fish and Wildlife Service, 1997). The 2014 SoSS workshop built upon the foundations of the 1997 workshop, with particular emphasis on changes in the condition of the Sea and its environment in the intervening years. Over the past five decades, investigations of the Salton Sea have addressed water quality, biological, recreation, and (or) economic issues at the Salton Sea (California Resources Agency, 2006, chap. 8). Many stakeholders believe that the Salton Sea has been “studied to death” (Claiborne, 1996). Although it is true that a great deal of research has been completed at the Salton Sea, much of it has been short term and focused on specific topics with little or no integration across science disciplines, time, and space. Additionally, there have been numerous attempts at resource management of the Salton Sea (previously referred to as restoration planning).  Study objectives have differed, but the main focus has generally been on methods to control the salinity and elevation of the Salton Sea (California Resources Agency, 2006, chaps. 1 and 4). Most investigations resulted in proposed plans to preserve the Salton Sea as a thriving fishery and recreational destination, and most of these plans addressed methods to preserve the “whole Sea.” More recently, however, studies have recognized that maintaining a smaller Salton Sea should be considered, owing to declining inflows to the Salton Sea (California Resources Agency, 2006).  Prior investigations considered hundreds of alternatives for managing Salton Sea salinity, nutrients, and water elevation. Some alternatives generated revenue to help pay for rehabilitating the Sea. These alternatives have been addressed in multiple studies, as summarized in chapters 1 and 4 of the “Salton Sea Ecosystem Restoration Program Draft Programmatic Environmental Impact Report” (California Resources Agency, 2006).  Although there have been multiple efforts to characterize the Salton Sea ecosystem and develop management plans, it was not until 1996 that a comprehensive and integrated research needs assessment was developed (U.S. Fish and Wildlife Service, 1997). The 1997 report captured the combined thinking of scientists and managers and identified several areas of scientific research that would be required for a fuller, more complete understanding of the Salton Sea necessary to undertake any management project. The report defined these broad categories of science as physical environment, biological environment, cultural resources, pathogens and diseases, and contaminants. These categories form the basic framework for all scientific investigations at the Salton Sea. Some science categories continue to receive greater emphasis because limited funding has required the prioritization of projects.  A Salton Sea Science Subcommittee (SSC) authorized by Public Law 105–372, representing a broad range of Federal, State, local, and other stakeholder interests, endorsed a long-range Strategic Science Plan for the Salton Sea (Salton Sea Science Subcommittee, 2000). Whereas the U.S. Fish and Wildlife Service 1997 report established the types of science needed, the SSP further established the governing processes and expectations of how this science program should be conducted. The SSP provided the framework for scientific investigations and remains the source for identifying how scientific studies should be undertaken to better understand the Salton Sea ecosystem. Based substantially on the U.S. Fish and Wildlife Service (1997) analysis of science needs, and in consultation with many stakeholders, the SSC authorized and funded a number of initial reconnaissance-level projects. The structure of this SoSS document follows the basic framework of the U.S. Fish and Wildlife Service 1997 report, placing emphasis on physical environment (air and water quality), biological environment (birds, fish, invertebrates, carbon, and algae), contaminants, and socioeconomics.  The SoSS meeting in 2014 was convened to build upon previous scientific efforts and to provide guidance to managers on what experts believe are the most critical science needs going forward. Experts were invited to participate in the SoSS meeting based on a review by the organizing committee of individuals with subject area expertise and experience working at the Salton Sea or in similar environments. The SoSS organizing committee presented a synopsis of known science to the gathered scientists, who were then tasked to evaluate the completeness of that science and make recommendations for science needs to fill information gaps. Participants were challenged to think and act independently of their organizational affiliation in order to generate conceptual proposals designed to address scientific and monitoring concerns identified by the managerial meeting participants.

State Plan of Flood Control Descriptive Document (2010)

California Department of Water Resources (DWR) | January 15th, 2010

This report provides an inventory and description of the existing flood control works (facilities), lands, programs, plans, conditions, and mode of operations and mainten

This report provides an inventory and description of the existing flood control works (facilities), lands, programs, plans, conditions, and mode of operations and maintenance (O&M) for the State-Federal flood protection system in the Central Valley of California. This flood protection system is composed of federally authorized project levees and related facilities for which the State has provided assurances1 of cooperation to the federal government. These State-provided assurances are an important distinction for what constitutes the State-federal flood protection system since other flood protection facilities in the Central Valley are not covered by State assurances and are not part of the State-federal system. Collectively, the facilities, lands, programs, conditions, and mode of O&M for the State-Federal flood protection system in the Central Valley are referred to as the State Plan of Flood Control (SPFC). This SPFC Descriptive Document is the first time that an inventory of the SPFC has been compiled or referenced in a single document. Until now, much of the information on the SPFC has been individually maintained for each of the many flood protection projects that constitute State-federal flood protection along the Sacramento and San Joaquin rivers and tributaries. For example, much of the information contained in sections of this report originates in 118 individual project (unit-specific) O&M manuals. The O&M manuals provide key information about each project and how it should be operated and maintained (see reference digital versatile disc (DVD) at the back of this report). In addition, since the individual projects for the system were implemented over almost a century, some information may have been lost or never obtained. In those cases, gaps exist in the information presented in this report and further research is required. It is important to note that the SPFC is only a portion of the larger system that provides flood protection for the Central Valley. The SPFC relies on many other features that do not meet the definition of the SPFC. For example, non-SPFC reservoirs provide substantial regulation of flows to levels that SPFC facilities can mostly handle. Private levees, locally operated drainage systems, and other facilities work in conjunction with SPFC facilities. Management practices such as emergency response, floodplain management, and other practices are part of the overall flood protection system. All parts of the system, including the SPFC, depend on other parts of the system to operate as a unit. This report is structured as a reference document for the SPFC. It includes narrative descriptions, tables, and figures, especially maps, to help the reader find information for this complex flood management system. Some sections include summary sections for readers who only need an overview of the subject. RELATED DOCUMENT: State Plan of Flood Control Descriptive Document 2016 Update

State Plan of Flood Control Descriptive Document 2016 Update

California Department of Water Resources (DWR) | December 14th, 2016

The November 2016 State Plan of Flood Control (SPFC) Descriptive Document Update (2016 Update) is intended to serve as a reference for flood management planners and opera

The November 2016 State Plan of Flood Control (SPFC) Descriptive Document Update (2016 Update) is intended to serve as a reference for flood management planners and operators at the local, State, and federal levels. It is not a stand-alone document; rather, it works in conjunction with the November 2010 SPFC Descriptive Document, builds upon information presented in the original report, and documents changes to the SPFC that have occurred between November 2010 and July 2016. The 2016 Update documents the inventory of flood control projects and works (facilities), lands, programs, plans, conditions, and mode of operations and maintenance for the State-federal flood management system in the Sacramento River and San Joaquin River watersheds of California, as well as informs the 2017 Central Valley Flood Protection Plan Update. In 2006 and 2007, California voters approved the Disaster Preparedness and Flood Prevention Bond Act of 2006 and the Central Valley Flood Protection Act of 2008 respectively. These acts defined the Sacramento River and San Joaquin River federal-State flood control projects as the SPFC, and required DWR to develop, and the Central Valley Flood Protection Board to adopt, a Central Valley Flood Protection Plan. The Central Valley Flood Protection Plan is broader than the SPFC, affecting the entire watersheds of the Sacramento and San Joaquin valleys. A complex system of dams and reservoirs, levees, weirs, bypasses, and other features constructed piecemeal over the last 100 years protects urban and rural areas against most flooding. This system has prevented billions of dollars in damage in its lifetime. A portion of this complex flood protection system includes State and federally authorized projects for which the Central Valley Flood Protection Board or DWR has provided assurances of cooperation to the federal government, known as the SPFC. These statutory authorizations include provisions regarding responsibility for operation and maintenance of the flood control facilities. The California Legislature has authorized funding for numerous flood control projects throughout the Sacramento and San Joaquin River watersheds. As the SPFC evolves, updates to the SPFC Descriptive Document will be useful in determining funding eligibility for funding for facility improvements. RELATED DOCUMENT:  State Plan of Flood Control (2010)