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This report summarizes the precipitation, discharge, and sediment conditions observed from October 1, 2016 to September 30th, 2017 (Water Year (WY) 2017) in the Arroyo de la Laguna watershed, with a focus on the Arroyo Mocho watershed. This information was collected by the Zone 7 Water Agency to support operation and maintenance of their flood control facilities. Additionally, this and similar information collected in WY 2018 and 2019 will be utilized to update the Arroyo Mocho watershed sediment budget (Pearce et al, 2020).

The reach of ADLL between the Arroyo Del Valle confluence (at the Interstate 680 crossing) and Verona Road is currently experiencing significant changes to its channel morphology, namely incision and widening, leading to bank erosion and bank failures. Many of the parcels adjacent to the stream channel are experiencing loss of property and damage or loss of some bank-top structures. The complex history of this reach makes it difficult to determine the current and future condition and functioning. In an effort to understand the ADLL geomorphic processes and channel evolutionary pathway, Zone 7 has partnered with SFEI to create this Reach-based Geomorphic Evaluation report that will serve as a reference for the historical, current, and likely future condition of the reach, and will provide broader context to inform decisions about potential restoration projects.

The Preparing for the Storm project, led by Zone 7 Water Agency (Zone 7) and funded by the US Environmental Protection Agency (EPA) Water Quality Improvement Fund, aims to develop science-based plans, strengthen existing and new partnerships, and pilot new methodologies for tackling these issues surrounding coarse sediment. As a task within this larger project, this report describes four projects in the East Bay that serve as case studies for beneficial reuse of sediment. Each example highlights a project with sediment that could be reused (in lieu of landfilling) or a project that needs additional sediment and could benefit from deliveries of sediment that normally would not have been beneficially reused.

Historic and current regional management of watersheds and channels for water supply and flood control across the San Francisco Bay Area has cut off much of the coarse sediment that was historically delivered to the Bay. Here we define coarse sediment as having grain sizes larger than 0.0625 mm, which includes sand, gravel and even cobble, as opposed to fine sediment that includes clay, mud and silt. Future projections indicate that sediment supply will not meet the demand from extant and restored tidal marshes to keep up with sea level rise.

The US EPA Water Quality Improvement Fund Preparing for the Storm grant has funded the Zone 7 Water Agency, the San Francisco Estuary Institute and the San Francisco Bay Joint Venture to support the future development of a successful regional coarse sediment reuse strategy. Development of such a strategy requires an understanding of logistical and regulatory hurdles and identification of key strategies for breaking down barriers. One potential solution for meeting the sediment demand along the Bay margin is to utilize coarse sediment that is removed from flood control channels by public agencies. To-date, very little of this sediment that is removed is beneficially reused for restoration along the Bay shoreline. The current economic and regulatory framework around sediment removal presents many challenges, barriers and lack of incentives for agencies to reuse their sediment.

This document represents a step forward towards beneficially reusing coarse flood control channel sediment by outlining reuse challenges, and identifying incentives for participation and potential solutions.

The “Sycamore Alluvial Woodland Restoration and Enhancement Suitability Study” addresses distribution and regeneration patterns and restoration strategies of sycamore alluvial woodland (SAW) habitat, a unique and relatively rare native vegetation community adapted to California’s intermittent rivers and streams. The report was produced by SFEI and H. T. Harvey & Associates, as part of the US EPA Water Quality Improvement Fund Preparing for the Storm grant, led by Zone 7 Water Agency.

 The Laguna de Santa Rosa, located in the Russian River watershed in Sonoma County, CA, is an expansive freshwater wetland complex that hosts a rich diversity of plant and wildlife species, many of which are federally or state listed as threatened, endangered, or species of special concern. The Laguna is also home to a thriving agricultural community that depends on the land for its livelihood. Since the mid-19th century, development within the Laguna and its surrounding watershed have had a considerable impact on the landscape, affecting both wildlife and people. Compared to pre-development conditions, the Laguna currently experiences increased stormwater runoff and flooding, increased delivery and accumulation of fine sediment and nutrients, spread of problematic invasive species, and decreased habitat for native fish and wildlife species. Predicted changes in future precipitation patterns and summertime air temperatures, combined with expanding development pressure, could exacerbate these problems. People who manage land and regulate land management decisions in and around the Laguna, including landowners; federal, state, and local agencies; and local stakeholders, are seeking a long-term management approach for the Laguna that improves conditions for the wildlife and people that call the Laguna home. The California Department of Fish and Wildlife and Sonoma Water funded the Laguna-Mark West Creek Watershed Master Restoration Planning Project to develop such a management approach, focusing on the need to identify restoration and management actions that enhance desired ecological functions of the Laguna, while also supporting the area’s agriculture and its local residents.

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.

Printed copies of the report are available for purchase.

A Delta Renewed User Guide aims to increase the accessibility of the technical findings in A Delta Renewed for easier application to restoration and conservation efforts across the Delta. The recommendations in A Delta Renewed focus on landscape-scale ecological guidance. We present three examples of how the information in A Delta Renewed might be used to address different management and restoration questions. Because of the complexity of the Delta system, this guide does not address all possible questions and does not replace the need for detailed, site-specific data and expertise. Rather, it shows how the information in A Delta Renewed might provide a common foundation for restoration planning.

The User Guide was written for a broad audience, including restoration practitioners, landowners, and local, state and federal agencies. The guide provides a step-by-step path through A Delta Renewed; a user is walked through how to apply the findings of the report via a series of steps to address each of the three restoration and management questions. This process is intended to help the user access regionally-specific recommendations and strategies to plan and manage future Delta landscapes that can support desired ecological functions over the long term.

The goal of A Delta Renewed and this guide is not to recreate the Delta of the past. Rather, the objective is to understand how we can re-establish or mimic important natural processes and patterns within this altered system to support desirable ecological functions (such as healthy native fish populations, a productive food web, and support for endangered species), now and into the future.

Microplastic contamination in the marine environment is a global issue. Across the world, policies at the national and international level are needed to facilitate the scale of change needed to tackle this significant problem. However, sources and patterns of plastic contamination vary around the world, and the most pressing actions differ from one location to another. Therefore, local policies are a critical part of the solution; recognizing local sources will enable mitigations with measurable impacts. Here, we highlight how investigating the contamination comprehensively in one location can inform relevant mitigation strategies that can be transferred globally. We examine the San Francisco Bay in California, USA—the largest estuary on the West Coast of the Americas, and home to over 7 million people. The local contamination of microplastics in surface water, sediments, and fish from this urban bay is reportedly higher than many places studied to date.(1) This example demonstrates the value of local monitoring in identifying sources, informing local mitigation strategies and developing an array of solutions to stem the multifaceted tide of plastic pollution entering our global oceans.

Urban pest control insecticides, specifically fipronil and its four major degradates (fipronil sulfone, sulfide, desulfinyl, and amide) and imidacloprid, were monitored during drought conditions in eight San Francisco Bay wastewater treatment plants (WWTPs). In influent and effluent, ubiquitous detections were obtained in units of ng/L for fipronil (13-88), fipronil sulfone (1-28), fipronil sulfide (1-5) and imidacloprid (58-306). In influent, 100% of imidacloprid and 62 ± 9% of total fiproles (fipronil and degradates) were present in the dissolved state, with the balance being bound to filter-removable particulates. Targeted insecticides persisted during wastewater treatment, regardless of treatment technology utilized (imidacloprid: 93 ± 17%; total fiproles: 65 ± 11%), with partitioning into sludge (3.7-151.1 μg/kg dry weight as fipronil) accounting for minor losses of total fiproles entering WWTPs. The load of total fiproles was fairly consistent across the facilities but fiprole speciation varied. This first regional study on fiprole and imidacloprid occurrences in raw and treated California sewage revealed ubiquity and marked persistence to conventional treatment of both phenylpyrazole and neonicotinoid compounds. Flea and tick control agents for pets are identified as potential sources of pesticides in sewage meriting further investigation and inclusion in chemical-specific risk assessments. 

Hot springs in the Tijuana River? Antelope by the beach? Zip-lines over the international border?
Come find out what the Tijuana River Valley looked like in the not-so-distant past and how the river, estuary, and surrounding areas have changed over the past two centuries. Hear how researchers “recreated” the historical landscape and how this information helps us to better plan for the future.

The Tijuana River Valley Historical Ecology Investigation addresses a regional data gap by reconstructing the landscape and ecosystem characteristics of the river valley prior to the major modifications of the late 19th and 20th centuries. The research presented here, funded by the California State Coastal Conservancy, supplies foundational information at the regional and system scale about how the Tijuana Estuary, River, and valley looked and functioned in the recent past, as well as how they have changed over time. The ultimate goal of this study is to provide a new tool and framework that, in combination with contemporary research and future projections, can support and guide ongoing restoration design, planning, and management efforts in the valley.

The goals of the Mission Bay Historical Ecology Reconnaissance Study were to collect and compile high-priority historical
data about the Mission Bay landscape, identify sources that could help to develop a deeper understanding of early
ecological conditions, and to identify future possible research directions based on the available data. This technical
memorandum is intended to document the archives consulted during the reconnaissance study, summarize the collected
and compiled data, and to identify potential next steps. A separate technical presentation to project staff and advisors will
summarize the preliminary findings and questions generated from a review of the historical dataset. Ultimately, this
research is intended to support the San Diego Audubon Society’s Mission Bay Wetlands Conceptual Restoration Plan (CRP)
and the ReWild Mission Bay project.

The physical and ecological environment of the upper San Francisco Estuary has been profoundly altered since the early 1800s. Recent efforts have utilized maps of the upper estuary’s historical habitat types to infer associated changes in desired ecosystem processes and functions. The work presented in this memo builds on these previous efforts, but utilizes a new tool for evaluating change over time: a 3D hydrodynamic model of the pre-development estuary. This model was constructed by Resource Management Associates (RMA) using a new digital elevation model of the pre-development upper estuary generated by SFEI and UC Davis (UCD) and “natural” boundary flows calculated by the California Department of Water Resources (CDWR).

Once completed and calibrated, the pre-development model was paired with a similar model of the contemporary system in order to analyze hydrodynamic changes in the upper estuary. These analyses are presented in a technical memorandum published by RMA (2015). This memorandum takes these analyses and considers the ecological implications of modeled changes (see the “Results” section). Hydrodynamic analyses include analyzing changes in tidal prism, isohaline positions, low-salinity zone habitat, channel velocity, and source water distribution.

 In addition to describing the ecological implications of modeled hydrodynamic changes, this memorandum summarizes major ongoing questions about estuarine hydrodynamics that might be explored using these models, including changes in water residence time, temperature, transport pathways, and the connectivity of aquatic and semi-aquatic habitats. Understanding changes in these and other factors would greatly improve our understanding of the desirable ecosystem functions provided by the historical system and, as a result, improve our ability to recover these functions now and into the future.