2016 Updated ambient concentrations of toxic chemicals in San Francisco Bay area sediments

San Francisco Estuary Institute (SFEI) | February 26th, 2016

 The purpose of this memo is to communicate the most recent results for the ambient concentrations of mercury, Total PAHs and Total PCBs in San Francisco Bay area sedime

 The purpose of this memo is to communicate the most recent results for the ambient concentrations of mercury, Total PAHs and Total PCBs in San Francisco Bay area sediments.  Regulation of dredging and dredged material disposal or reuse under the San Francisco Bay Long Term Management Strategy for Dredging (LTMS) involves, in part, evaluation of sediment chemistry characteristics. For dredged material in California, for most chemicals, there are no numeric sediment quality standards or objectives that define chemical suitability for disposal or reuse at particular placement sites.1 Consequently, Bay dredged sediments are compared to various published screening values and other guidelines, to reference site chemistry, and where available and appropriate, to ambient sediment contaminant concentrations for the Bay as a whole. Therefore, starting in 2011, the LTMS agencies have asked SFEI to calculate the ambient concentrations for a small subset of sediment contaminants that are either subject to TMDL limits for in-Bay dredged material disposal or are relevant for bioaccumulation testing for dredging (DMMO, n.d.). 

2018 Clear Creek Technical Team Annual Report for the Coordinated Long-Term Operations Biological Opinion

Delta Stewardship Council (Delta Council) | July 1st, 2019

2019 Technical Memorandum Regarding the Accounting of San Joaquin River Spring-run Chinook Salmon at the Central Valley Project and State Water Project Sacramento-San Joaquin Delta Fish Collection Facilities

National Marine Fisheries Service (NMFS) | January 15th, 2019

2020 Annual Report on the Salton Sea Management Program

California Natural Resources Agency (CNRA) | February 21st, 2020

Improving air quality and creating habitat at the Salton Sea are key priorities for Governor Gavin Newsom and the California Natural Resources Agency. The Sea’s continu

Improving air quality and creating habitat at the Salton Sea are key priorities for Governor Gavin Newsom and the California Natural Resources Agency. The Sea’s continuing decline in elevation and resulting exposure of lakebed negatively impact surrounding communities and reduce remaining habitat for fish and wildlife. The California Natural Resources Agency, the California Department of Water Resources, and the California Department of Fish and Wildlife (together, the State Team) are focused on implementing the Salton Sea Management Program’s (SSMP’s) 10-Year Plan to improve conditions by constructing 30,000 acres of habitat and dust suppression projects around the Sea.

A call for strategic water-quality monitoring to advance assessment and prediction of wildfire impacts on water supplies

Frontiers in Water (Frontiers) | March 13th, 2023

Wildfires pose a risk to water supplies in the western U.S. and many other parts of the world, due to the potential for degradation of water quality. However, a lack of a

Wildfires pose a risk to water supplies in the western U.S. and many other parts of the world, due to the potential for degradation of water quality. However, a lack of adequate data hinders prediction and assessment of post-wildfire impacts and recovery. The dearth of such data is related to lack of funding for monitoring extreme events and the challenge of measuring the outsized hydrologic and erosive response after wildfire. Assessment and prediction of post-wildfire surface water quality would be strengthened by the strategic monitoring of key parameters, and the selection of sampling locations based on the following criteria: (1) streamgage with pre-wildfire data; (2) ability to install equipment that can measure water quality at high temporal resolution, with a focus on storm sampling; (3) minimum of 10% drainage area burned at moderate to high severity; (4) lack of major water management; (5) high-frequency precipitation; and (6) availability of pre-wildfire water-quality data and (or) water-quality data from a comparable unburned basin. Water-quality data focused on parameters that are critical to human and (or) ecosystem health, relevant to water-treatment processes and drinking-water quality, and (or) inform the role of precipitation and discharge on flow paths and water quality are most useful. We discuss strategic post-wildfire water-quality monitoring and identify opportunities for advancing assessment and prediction. Improved estimates of the magnitude, timing, and duration of post-wildfire effects on water quality would aid the water resources community prepare for and mitigate against impacts to water supplies.

A conceptual model for floodplains in the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | October 3rd, 2012

Floodplains are among the most biologically productive and diverse ecosystems on Earth and they provide significant benefits to society such as attenuation of floodwaters

Floodplains are among the most biologically productive and diverse ecosystems on Earth and they provide significant benefits to society such as attenuation of floodwaters, groundwater recharge, filtration of nutrients and sediments, carbon sequestration, fisheries productivity and recreation.  However, floodplains are also among the most converted and threatened ecosystems.  Floodplain habitats in the Sacramento-San Joaquin Delta, and throughout California’s Central Valley, have been greatly reduced from their historic extent and key processes that create and maintain floodplains, such as flood flows and meander migration, have been greatly altered.  These widespread alterations to habitats and processes have lead to declines in many species’ populations in California’s Central Valley and Delta, creating challenges for both environmental and water management. To address these challenges numerous entities and programs are now focused on restoring floodplains and other Delta habitats.  This paper provides a conceptual model for floodplains that characterizes the key features and identifies the critical processes, drivers, and linkages that allow floodplains to produce a variety of functional outputs of management importance.  These outputs include: (1) the floodplain habitat mosaic, including riparian vegetation and its associated wildlife; (2) spawning and rearing habitat for native fish; and (3) food-web productivity that can support native fish on the floodplain as well as be exported to downstream ecosystems.  The model emphasizes that the production of these outputs from floodplains requires vertical and lateral hydrological connectivity across a broad range of flow conditions.  For example, long-duration flooding in the spring promotes native fish spawning and food-web productivity that benefits native species.

A decision‐support framework for dam removal planning and its application in northern California

Environmental Challenges (Elsevier) | May 27th, 2023

Dam removals are occurring more frequently with the rising cost of maintaining aging infrastructure, public safety concerns, and growing interest in river restoration. So

Dam removals are occurring more frequently with the rising cost of maintaining aging infrastructure, public safety concerns, and growing interest in river restoration. So far, most dam-removals have been unsystematic in their approach. Given the several thousand dam removals expected over the coming decades, a systematic approach to plan future dam removals holds potential for aligning and delivering multiple benefits. Despite multi-sector factors driving decision-making, most existing prioritization frameworks tend to operate within single or related disciplines. Here we present a hierarchical, multi-disciplinary decision-support framework to prioritize dam removals based on opportunistic factors (Tier 1), hydro-ecological variables (Tier 2), and socio-cultural considerations (Tier 3). This framework integrates multiple decision criteria under data availability constraints, incorporates value-driven weights, and can be applied to a portfolio of dams at various spatial scales. The final output facilitates the identification of dam removal projects that align opportunistic, environmental, and social benefits. We recommend the application of this framework as a critical first step to identifying high-priority candidates for removal, recognizing that removal decisions will ultimately require detailed feasibility studies and stakeholder engagement. To illustrate its utility, we apply this framework to California’s North Coast region and identify a small number of “good ”candidates to be considered for removal. We conclude with recommendations for filling critical knowledge gaps and advancing systematic dam removal planning in the United States and beyond.

A Delta Renewed: A Guide to Science-Based Ecological Restoration in the Sacramento-San Joaquin Delta

San Francisco Estuary Institute (SFEI) | November 15th, 2016

This final report of the Delta Landscapes Project, A Delta Renewed, offers guidance for creating and maintaining landscapes that can provide desired ecological functi

This final report of the Delta Landscapes Project, A Delta Renewed, offers guidance for creating and maintaining landscapes that can provide desired ecological functions for decades to come. Based on extensive research into how the Sacramento-San Joaquin Delta used to function, how it has changed, and how it is likely to evolve, we make recommendations for how to re-establish the dynamic natural processes that can sustain native Delta wildlife as healthy populations into the future. The approach, building on work others have piloted and championed, is to restore or emulate natural processes where possible, establish an appropriate configuration of habitat types at the landscape scale, and use multi-benefit management strategies to create a more viable Delta ecosystem that can adapt and continue to provide valued functions as the climate changes. This approach is designed to integrate with the human landscape: ecosystem improvements as a part of a robust agricultural economy, water infrastructure and diversions, and urbanized areas. Strategic restoration which builds on the history and ecology of the region can contribute to the strong sense of place and recreational value of the Delta in the future. See more at: http://www.sfei.org/projects/delta-landscapes-project#sthash.RryQdaII.dpuf

A Delta Renewed: A Guide to Science-Based Ecological Restoration in the Sacramento-San Joaquin Delta

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

This report offers guidance for creating and maintaining landscapes in the Sacramento-San Joaquin Delta that support desired ecological functions, while retaining the ove

This report offers guidance for creating and maintaining landscapes in the Sacramento-San Joaquin Delta that support desired ecological functions, while retaining the overall agricultural character and water-supply service of the region. Based on extensive research into how the Delta functioned historically, how it has changed, and how it is likely to evolve, we discuss where and how to re-establish the dynamic natural processes that can sustain native Delta habitats and wildlife into the future. The approach, building on work others have piloted and championed, is to restore or emulate natural processes where possible, establish an appropriate mosaic of habitat types at the landscape scale, use multi-benefit management strategies to increase support for native species in agricultural and urban areas, and allow the Delta to adapt to future uncertainties of climate change, levee failure, and human population growth. With this approach, it will be critical to integrate ecological improvements with the human landscape: a robust agricultural economy, water infrastructure and diversions, and urbanized areas. Strategic restoration that builds on the history and ecology of the region can contribute to the strong sense of place and recreational value of the Delta.

A Delta Renewed: A Guide to Science-Based Ecological Restoration in the Sacramento-San Joaquin Delta

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

A Delta Renewed and the larger Delta Landscapes project are part of an ongoing effort to address these critically important challenges. They provide guidance for restora

A Delta Renewed and the larger Delta Landscapes project are part of an ongoing effort to address these critically important challenges. They provide guidance for restoration that renews critical functions over time without having major negative impacts on the current human enterprise in the Delta area and on other areas dependent on its services. The idea is to determine the most efficient ways to recover Delta functioning so that human benefits are maintained, while investing in process-based recovery of landscape functions. The scientists working on this project assume that this goal is best achieved if we can understand how the Delta functioned before major European modification. We can then use that knowledge as a guide to developing a diverse portfolio of habitats and connections that might sustain native species, and the attributes of a healthy Delta into the future. The effort to reconstruct the Delta of the early 1800s has been challenging, but is now completed. The next step is to devise management scenarios that will recover important functions and native species where possible. There is no intent to try to recreate the Delta of the past. That is impossible without sacrificing our objective of maintaining and even improving the human enterprises now present. What is essential now is to obtain general agreement among all of the stakeholders, which includes all citizens of California, that the Delta should be managed for the benefit of people and wildlife in a sustainable way. Given the uncertainties inherent in any large-scale reconciliation effort, there is a real need to appreciate the complex interactions and inter-dependencies that characterize the various components of the Delta landscape. There is also a need to understand the uncertainties of future climate change and to recognize the diversity of needs among our fellow citizens. Our hopes for success will ultimately depend on generating a spirit of cooperation for the common good. It won’t be easy, but the stakes are high. The Delta Landscapes project is dedicated to that goal.