McKee, L.; Peterson, D.; Braud, A.; Foley, M.; Dusterhoff, S.; Lowe, J.; King, A.; Davis, J. 2023. San Francisco Bay Sediment Modeling and Monitoring Workplan.  SFEI Contribution No. 1100. San Francisco Estuary Institute: Richmond, CA.
This document was prepared with guidance gained through two RMP Sediment Workgroup workshops held in late 2022 and early 2023. Given the variety of participants involved, this Workplan encompasses interests beyond San Francisco Bay RMP funders. We thank the attendees for their contributions. 
In 2020, the Sediment Workgroup (SedWG) of the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) completed a Sediment Monitoring and Modeling Strategy (SMMS) which laid out a conceptual level series of data and information gaps and generally recommended the use of both empirical data collection and modeling tools to answer initial high priority management questions (McKee et al., 2020). At the time, the SMMS promoted the use of surrogates such as time-continuous turbidity measurements for cross-section flux modeling within the Bay without an understanding of existing Bay hydrodynamic models, their strengths, weaknesses, and potential uses for understanding coupled Bay-mudflat-marsh processes. Since then, the Wetland Regional Monitoring Program (WRMP, www.wrmp.org) has generally promoted the use of coupling monitoring and modeling techniques to inform wetlands sediment management decisions. In addition, he completion of the Sediment for Survival report (a RMPEPA funded collaboration) and the further development of sediment conceptual models has also advanced the need for a coupled dynamic modeling and monitoring program that has the capacity to explore more complex management questions (Dusterhoff et al., 2021; SFEI, 2023). Such a program will take time to develop, but will be more cost-efficient and adaptable and allow for more timely answers to pressing questions. 

Dusterhoff, S.; McKnight, K.; Grenier, L.; Kauffman, N. 2021. Sediment for Survival: A Strategy for the Resilience of Bay Wetlands in the Lower San Francisco Estuary.  SFEI Contribution No. 1015. San Francisco Estuary Institute: Richmond, CA.
This report analyses current data and climate projections to determine how much natural sediment may be available for tidal marshes and mudflats and how much supplemental sediment may be needed under different future scenarios. These sediment supply and demand estimates are combined with scientific knowledge of natural physical and biological processes to offer a strategy for sediment delivery that will allow these wetlands to survive a changing climate and provide benefits to people and nature for many decades to come. The approach developed in this report may also be useful beyond San Francisco Bay because shoreline protection, flood risk-management, and looming sediment deficits are common issues facing coastal communities around the world.
The resilience of San Francisco Bay shore habitats, such as tidal marshes and mudflats, is essential to all who live in the Bay Area. Tidal marshes and tidal flats (also known as mudflats) are key components of the shore habitats, collectively called baylands, which protect billions of dollars of bay-front housing and infrastructure (including neighborhoods, business parks, highways, sewage treatment plants, and landfills). They purify the Bay?s water, support endangered wildlife, nurture fisheries, and provide people access to nature within the urban environment. Bay Area residents showed their commitment to restoring these critical habitats when they voted for a property tax to pay for large-scale tidal marsh restoration. However, climate change poses a great threat, because there may not be enough natural sediment supply for tidal marshes and mudflats to gain elevation fast enough to keep pace with sea-level rise.

Dusterhoff, S.; McKnight, K.; Grenier, L.; Kauffman, N. 2021. Sediment for Survival fact sheet.

Mckee, L.; Lowe, J.; Dusterhoff, S.; Foley, M.; Shaw, S. 2020. Sediment Monitoring and Modeling Strategy. Sediment Monitoring and Modeling Strategy.  SFEI Contribution No. 1016. San Francisco Estuary Institute: Richmond, CA.

Schoellhamer, D.; McKee, L.; Pearce, S.; Kauhanen, P.; Salomon, M.; Dusterhoff, S.; Grenier, L.; Marineau, M.; Trowbridge, P. 2018. Sediment Supply to San Francisco Bay.  SFEI Contribution No. 842. San Francisco Estuary Institute : Richmond, CA.

Salomon, M.; Dusterhoff, S. D.; Askevold, R. A.; Grossinger, R. M. 2016. San Francisquito Creek Baylands: Landscape Change Metrics Analysis. Flood Control 2.0.  SFEI Contribution No. 784. San Francisco Estuary Institute - Aquatic Science Center: Richmond, CA. p 12.
Major Findings<br />Over the past 150 years, lower San Francisquito Creek and the adjacent baylands have been modified for the sake of land reclamation and flood control. This study focused on developing an understanding of the magnitude of habitat change since the mid-19th century through comparisons of key historical and contemporary landscape-scale habitat features, as well as several key landscape metrics that relate to ecological functions and landscape resilience. The major findings from the analyses conducted for this study are as follows:<br />? Historically, the San Francisquito Creek Baylands included a mosaic of habitat types, including an extensive tidal marsh plain with salt pannes and an expansive tidal channel network, a broad bay flat, and a relatively wide contiguous low-gradient tidal-terrestrial transition zone.<br />? Since the late 19th century, a combination of land reclamation and the inland migration of the shoreline has resulted in a 55% decrease in tidal marsh area, a 67% decrease in total tidal channel length, a 40% reduction in channel flat area, a 20% increase in bay flat area, and a 95% decrease in tidal-terrestrial transition zone length.<br />? Land reclamation has also resulted in the creation of new features that did not exist in the area historically including tidal lagoons, non-tidal open water features, and non-tidal wetlands.<br /> 
Recommendations<br />The findings from this study provide insight into the drivers for and magnitude of habitat change within the San Francisquito Creek Baylands, and can therefore help inform climate-resilient approaches for regaining some of the lost landscape features and ecological functions. Specific management recommendations developed from the study findings are as follows:<br />? The dramatic decrease in tidal marsh area and associated tidal channel length since the mid-1800s make tidal marsh restoration a high priority. To make restored areas sustainable over the long-term, restoration should include reestablishing regular tidal inundation as well as reestablishing a connection with San Francisquito Creek and the delivery of freshwater and fine sediment. Restoration efforts should focus on large contiguous areas with minimal infrastructure and should ideally be done sometime over the next decade to ensure the restored areas will have a chance of surviving the sharp increase in the rate of sea level rise that is predicted to occur around 2030 (Goals Update 2015).<br />? Similarly, the dramatic decrease in the tidal-terrestrial transition zone makes it a high priority for any restoration vision for this area. The transition zone provides distinct ecological services and marsh migration space, and is in need of restoration throughout the South Bay. Since most of the upland land along the historical tidal-terrestrial transition zone is currently developed, near-term restoration efforts should focus on creating transition zone habitats on the bayside of flood risk management levees (Goals Update 2015).<br />? The landscape metrics used in this study (tidal habitat area, tidal channel length, and tidal-terrestrial interface length) can be used to help design resilient landscape restoration and adaptation strategies around the mouth of San Francisquito Creek. Specifically, the metrics can be used to assess the long-term ecological benefit associated with various processes-based restoration approaches (i.e., approaches that create habitat features and establish physical processes required for habitat resilience). Additional useful landscape metrics are being developed as part of the Resilient Silicon Valley project (see Robinson et al. 2015).