Report on Feasibility of Feather River Project and Sacramento-San Joaquin Delta Diversion Projects Proposed as Features of the California Water Plan

California Department of Water Resources (DWR) | May 17th, 1951

Resilient by Design Bay Area Challenge Briefing Book

San Francisco Estuary Institute (SFEI) | July 1st, 2017

The Resilient by Design Bay Area Challenge Briefing Book is intended as a reference guide for Design Teams as they embark on the Challenge. The aim is to provide com

The Resilient by Design Bay Area Challenge Briefing Book is intended as a reference guide for Design Teams as they embark on the Challenge. The aim is to provide compilation of useful existing resources and context pertaining to resilience in the Bay Area.

Resilient landscape vision for Lower Walnut Creek

San Francisco Estuary Institute (SFEI) | November 30th, 2016

Lower Walnut Creek (Contra Costa County, CA) and its surrounding landscape have undergone considerable land reclamation and development since the mid-nineteenth century.

Lower Walnut Creek (Contra Costa County, CA) and its surrounding landscape have undergone considerable land reclamation and development since the mid-nineteenth century. In 1965, the lower 22 miles of Walnut Creek and the lower reaches of major tributaries were converted to flood control channels to protect the surrounding developed land. In the recent past, sediment was periodically removed from the lower Walnut Creek Flood Control Channel to provide flow capacity and necessary flood protection. Due to the wildlife impacts and costs associated with this practice, the Contra Costa County Flood Control and Water Conservation District (District) is now seeking a new channel management approach that works with natural processes and benefits people and wildlife in a cost-effective manner. Flood Control 2.0 project scientists and a Regional Science Advisory Team (RSAT) worked with the District to develop a long-term management Vision for lower Walnut Creek that could result in a multi-benefit landscape that restores lost habitat and is resilient under a changing climate. Development of the Vision began with technical analyses focused on understanding past and present landscape functioning and the changes to key processes and landscape features over the past 150 to 200 years. The key findings from these analyses include the following: • Landscape change – During the mid-19th century, lower Walnut Creek was surrounded by a continuous expanse of tidal wetlands occupying approximately 5,000 acres. Perennial freshwater marsh, willow thicket, and alkali meadow formed a large non-tidal wetland complex that adjoined the tidal marsh on its southern end. Over the past century and a half, the non-tidal wetland complex has been lost completely and the tidal wetland area has decreased by 40%. The remaining marsh areas are highly fragmented and cut-off from Walnut Creek by engineered levees. The loss of tidal wetland area has resulted in a substantial decrease in tidal prism and contributed to current in-channel sediment accumulation issues. Around the mouth of Walnut Creek, sediment accumulation has caused the position of the shoreline to expand into the Bay by up to half a mile. • Sediment accumulation – Since 1965, approximately 1.4M cubic yards of sediment have been removed from lower Walnut Creek, with approximately 70% coming from the tidal zone downstream of head of tide (i.e., the inland extent of tidal inundation at mean higher high water). Repeat channel cross-section surveys indicate that the channel quickly fills in with sediment following dredging events (due in large part to decreased tidal prism and associated channel scour capacity) and that the channel bed elevation is currently at or near “quasi-equilibrium.” A channel sediment budget for 1965-2007 indicates that approximately 80% of the watershed-derived sediment made it through lower Walnut Creek and out to the Bay, while the remaining 20% was likely deposited directly following channel construction and subsequent dredging events.

Resilient Landscape Vision for Lower Walnut Creek: Baseline Information and Management Strategies

San Francisco Estuary Institute (SFEI) | November 1st, 2016

Lower Walnut Creek (Contra Costa County, CA) and its surrounding landscape have undergone considerable land reclamation and development since the mid-nineteenth century.

Lower Walnut Creek (Contra Costa County, CA) and its surrounding landscape have undergone considerable land reclamation and development since the mid-nineteenth century. In 1965, the lower 22 miles of Walnut Creek and the lower reaches of major tributaries were converted to flood control channels to protect the surrounding developed land. In the recent past, sediment was periodically removed from the lower Walnut Creek Flood Control Channel to provide flow capacity and necessary flood protection. Due to the wildlife impacts and costs associated with this practice, the Contra Costa County Flood Control and Water Conservation District (District) is now seeking a new channel management approach that works with natural processes and benefits people and wildlife in a cost-effective manner. Flood Control 2.0 project scientists and a Regional Science Advisory Team (RSAT) worked with the District to develop a long-term management Vision for lower Walnut Creek that could result in a multi-benefit landscape that restores lost habitat and is resilient under a changing climate. 

Resilient Landscape Vision for the Calabazas Creek, San Tomas Aquino Creek, and Pond A8 Area: Bayland-Creek Reconnection Opportunities

San Francisco Estuary Institute (SFEI) | May 1st, 2018

This report proposes a multi-faceted redesign of the South San Francisco Bay shoreline at the interface with Calabazas and San Tomas Aquino creeks. Recognizing the opport

This report proposes a multi-faceted redesign of the South San Francisco Bay shoreline at the interface with Calabazas and San Tomas Aquino creeks. Recognizing the opportunities presented by changing land use and new challenges, such as accelerated sea-level rise, we explore in this report a reconfigured shoreline that could improve ecosystem health and resilience, reduce maintenance costs, and protect surrounding infrastructure. 

Resilient Landscape Vision for Upper Penitencia Creek

San Francisco Estuary Institute (SFEI) | January 1st, 2019

This report proposes a new multi-benefit approach to flood management along Upper Penitencia Creek. Recognizing the creek’s complex history, land use, and challenges, t

This report proposes a new multi-benefit approach to flood management along Upper Penitencia Creek. Recognizing the creek’s complex history, land use, and challenges, this report explores a suite of actions that could help meet flood management objectives while improving ecosystem functioning, expanding recreational opportunities, and supporting water supply needs. 

Response of the upper ocean to northeast Pacific atmospheric rivers under climate change

Nature Portfolio (Springer Nature) | October 19th, 2024

Click here for a plain language summary from the National Center for Atmospheric Research

Click here for a plain language summary from the National Center for Atmospheric Research

Retrofitting Sustainable Urban Drainage Systems (SuDS): A Cost-Benefit Analysis Appraisal

Water (MDPI) | August 16th, 2022

Sustainable Urban Drainage Systems (SuDS) are known to help mitigate flooding whilst simultaneously delivering other positive outcomes, such as the provision of environme

Sustainable Urban Drainage Systems (SuDS) are known to help mitigate flooding whilst simultaneously delivering other positive outcomes, such as the provision of environmental, economic, educational, and business benefits. Despite this, there has been a relatively low uptake of SuDS in new developments and even less of an uptake in the opportunities for retrofitting SuDS in existing buildings. A major barrier to uptake has been a lack of understanding regarding the value of the benefits provided by SuDS. This study presents an appraisal of the costs and benefits derived from the retrofitting of SuDS in existing buildings and reveals some of the key decision-making considerations during the design and installation of such schemes. A qualitative research approach that included a number of case studies of successfully retrofitted SuDS schemes within public buildings was conducted. A novel feature of the research was the use of the Willingness to Pay (WTP) approach to value the tangible and intangible benefits provided by the various schemes from the perspectives of the property owners. The findings revealed that the retrofit provided a net value to the client of over £100,000 over 10 years, a mean CBA ratio of 5.3/10, and a return on investment (ROI) that would be achieved in less than 3 years. The importance of stakeholder engagement during the decision-making process was highlighted in helping to overcome many of the design, installation, and maintenance challenges. The findings demonstrate a significant ROI for these SuDs retrofit schemes and highlight useful approaches to overcoming the barriers in valuing the importance of the intangible benefits. In supporting the uptake of the retrofitting of SuDS, it is recommended that these benefits are given full consideration by property owners, urban planners, and architects during the design of retrofit schemes and throughout the decision-making stage.

Review of the Long-Term Operations of the Central Valley Project and the State Water Project

National Academy of Sciences (NAS) | November 10th, 2025

The CVP and SWP (referred to collectively as “the Projects”) rarely deliver their full contracted  amount of water. Some of this is inherent in the operation of larg

The CVP and SWP (referred to collectively as “the Projects”) rarely deliver their full contracted  amount of water. Some of this is inherent in the operation of large water projects with diverse demands in a dry and highly variable climate. A growing, complex regulatory environment of state and federal laws, some of which were created to protect fish species endemic to the Delta, has further restricted CVP and SWP operations.  These fish include the southern distinct population segment of North American green sturgeon, California Central Valley steelhead, Central Valley spring-run Chinook salmon, Sacramento River winter-run Chinook salmon, longfin smelt, and Delta smelt. Operating the Projects while trying to prevent species extinction can be a source of conflict if the actions to prevent extinction reduce the amount of water that can be exported. Project operation into the future will likely become more challenging as changes in various climatic factors push the listed species closer to their thresholds of survivability. Hence, in late 2023 USBR contracted with the National Academies of Sciences, Engineering, and Medicine (NASEM) to form an expert committee that could serve as an independent review for the CVP and SWP as they operate into the future. The Committee’s statement of task appears in Box S-1. The three actions chosen for the study—the Shasta Coldwater Pool Management Action, the Old and Middle River Flow Management Action, and the Summer-Fall Habitat Action for Delta Smelt— are perceived as consequential for species survival and controversial for their effects on water deliveries to contractors.

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