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Age Determination of the Remaining Peat in the Sacramento–San Joaquin Delta, California, USA
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Age Determination of the Remaining Peat in the Sacramento–San Joaquin Delta, California, USA
U.S. Geological Survey (USGS) | October 9, 2007...
Summary
The Sacramento–San Joaquin Delta of California was once a 1,400 square kilometer (km2) tidal marsh, which contained a vast layer of peat ranging...
The Sacramento–San Joaquin Delta of California was once a 1,400 square kilometer (km2) tidal marsh, which contained a vast layer of peat ranging up to 15 meters (m) thick (Atwater and Belknap, 1980). Because of its favorable climate and highly fertile peat soils, the majority of the Delta was drained and reclaimed for agriculture during the late 1800s and early 1900s.

Drainage of the peat soils changed the conditions in the surface layers of peat from anaerobic (having no free oxygen present) to aerobic (exposed to the atmosphere). This change in conditions greatly increased the decomposition rate of the peat, which consists largely of organic (plant) matter. Thus began the process of land-surface subsidence, which initially was a result of peat shrinkage and compaction, and later largely was a result of oxidation by which organic carbon in the peat essentially vaporized to carbon dioxide (Deverel and others, 1998; Ingebritsen and Ikehara, 1999).

Because of subsidence, the land-surface elevation on farmed islands in the Delta has decreased from a few meters to as much as 8 m below local mean sea level (California Department of Water Resources, 1995; Steve Deverel, Hydrofocus, Inc., written commun., 2007).

The USGS, in collaboration with the University of California at Davis, and Hydrofocus Inc. of Davis, California, has been studying the formation of the Delta and the impact of wetland reclamation on the peat column as part of a project called Rates and Evolution of Peat Accretion through Time (REPEAT). The purpose of this report is to provide results on the age of the remaining peat soils on four farmed islands in the Delta.

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Aluminum- and iron-based coagulation for in-situ removal of dissolved organic carbon, disinfection byproducts, mercury and other constituents from agricultural drain water

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Aluminum- and iron-based coagulation for in-situ removal of dissolved organic carbon, disinfection byproducts, mercury and other constituents from agricultural drain water
Elsevier | May 9, 2019...
Summary
Agricultural production on wetland soils can be significant sources of dissolved organic carbon (DOC), disinfection byproduct precursors, mercury and nutrients to downstream water bodies...
Agricultural production on wetland soils can be significant sources of dissolved organic carbon (DOC), disinfection byproduct precursors, mercury and nutrients to downstream water bodies and accelerate land subsidence. Presented as a potential solution for in-situ water quality improvement and land subsidence mitigation, chemically enhanced treatment wetlands (CETWs) were used to leverage both coagulation and wetland processes. In this study, we evaluated the performance of coagulants ferric sulfate (Fe dosing) and polyaluminum chloride (Al dosing) to remove pollutants from agricultural drain water using the coagulation system designed for CETWs. Both coagulation treatments removed over 70% DOC from source waters, resulting in removal efficiencies (mg-DOC removed per mg-metal dosed) of 1 under Al dosing and 0.5 under Fe dosing. Coagulation by both treatments preferentially removed UV254 active compounds compared to the bulk DOC concentration, suggesting coagulation targeted aromatics more effectively. Phosphates and haloacetic acids were also removed more readily, whereas trihalomethanes, dissolved organic nitrogen and filtered mercury species were removed at similar or lower rates than DOC. Dissolved inorganic nitrogen was not amenable to coagulation and removal was not observed. Freundlich, Langmuir and Monod models explained 33% of the variance in DOC removal for Al dosing and 78–89% of the variance for Fe dosing. All three models indicated Al dosing had higher removal efficiency and affinity for DOC than Fe dosing under study conditions, but when used to predict maximum removal efficiency there was no cohesiveness between the three models due to different model assumptions. Consideration of fluorescence dissolved organic matter and UV254 as surrogates for DOC concentration showed both were equally suitable before coagulant application, but as surrogates after coagulant application, neither could be deemed more fit as a surrogate since both were shown suitable for different treatment scenarios.

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An Evaluation of Compensatory Mitigation Projects Permitted Under Clean Water Act Section 401 by the California State Water Resources Control Board, 1991-2002
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An Evaluation of Compensatory Mitigation Projects Permitted Under Clean Water Act Section 401 by the California State Water Resources Control Board, 1991-2002
California State Water Resources Control Board | August 2, 2008...
Summary
The purpose of this project, which was funded by the California State Water Resources Control Board (SWRCB), was to evaluate the compliance and...
The purpose of this project, which was funded by the California State Water Resources Control Board (SWRCB), was to evaluate the compliance and wetland condition of compensatory wetland mitigation projects associated with Clean Water Act Section 401 Water Quality Certifications throughout California. This was done by selecting, reviewing and performing field evaluations for 143 permit files distributed across the 12 Water Board regions and sub-regions of the State. For each permit file we assessed the extent to which permittees complied with their mitigation conditions, including acreage requirements, whether the corresponding mitigation efforts resulted in optimal wetland condition, and if the habitat acreages gained through compensatory mitigation adequately replaced those lost through the permitted impacts. We found that permittees are largely following their permit conditions (although one-quarter to one-third of the time these are not met), but the resulting compensatory mitigation projects seldom result in wetlands with optimal condition.

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Analysis of the costs and benefits of using marsh restoration as a sea level rise adaptation strategy in San Francisco Bay
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Analysis of the costs and benefits of using marsh restoration as a sea level rise adaptation strategy in San Francisco Bay
The Bay Institute | February 22, 2013...
Summary
The purpose of this study is to examine opportunities to protect San Francisco Bay’s recovering tidal marsh ecosystems while helping bayshore communities to...
The purpose of this study is to examine opportunities to protect San Francisco Bay’s recovering tidal marsh ecosystems while helping bayshore communities to manage the impacts of sea level rise. Specifically, it considers the flood risk management functions that tidal marshes perform naturally and evaluates the possibility of integrating those functions into a co-beneficial shoreline management strategy. The study’s intended audience is planners, politicians, regulators, and other stakeholders with the authority to make or affect decisions that influence the configuration and use of the San Francisco Bay shoreline. The study examines the current functions of San Francisco Bay tidal marshes as well as existing flood risk management strategies. It considers how environmental conditions are likely to change in the era of climate change, and how we can adapt our marshes and our flood risk management practices to accommodate these changes.

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Applied Aquatic Science: A Business Plan for EcoAtlas

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Applied Aquatic Science: A Business Plan for EcoAtlas
San Francisco Estuary Institute (SFEI) | March 7, 2017...
Summary
The EcoAtlas suite of tools represents a significant investment of time, energy, thought, scientific testing, technical innovation, and capital from a number of...
The EcoAtlas suite of tools represents a significant investment of time, energy, thought, scientific testing, technical innovation, and capital from a number of state and federal public agencies, grant programs, and NGOs over the course of its 17-year existence. The toolset embodies the scientific and programmatic investments of the California Wetland Monitoring Workgroup (CWMW), its many related state and federal agencies, non-governmental organizations (NGOs), and private consultants, as well as the goals of the growing set of stakeholders who have expanded the circle of interested parties over the years. It is known by many names -- “WRAMP” being most common -- but in its essence it comprises the following tools:

● EcoAtlas map viewer

● Project Tracker

● The California Aquatic Resources Inventory (CARI) map and editor tool

● The California Rapid Assessment Method (CRAM)

● The Riparian Zone Estimator Tool (RipZET)

Now highly capable, the toolset represents more than science and technology alone, but a distillation of both, customized to meet specific goals associated with the landscape-scale tracking and characterization of California’s aquatic resources. The US Environmental Protection Agency (US EPA), for instance, has supported the toolset through multiple development grants so that the collected tools might be complementary to a still-nascent, statewide wetland protection program. Meanwhile, the state’s Coastal and Delta Conservancies require the use of the tool, and regional water boards -- including SF Bay, Lahontan, and North Coast -- regularly employ the tool for mitigation and restoration project tracking. Essentially, EcoAtlas has proven critical to a variety of programs and represents a successful product of broad-based collaboration. However, it currently stands at a crossroads, and its stakeholders must direct the toolset’s future. The following plan is intended to ensure the continued vitality of the toolset. The plan’s success will depend upon the continued collaboration of the public agencies that have supported the toolset thus far, but it must also integrate principles of resilience as it accounts for the tensions that arise as organizations move in different strategic directions.

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Assessment of the condition of San Francisco Bay Area depressional wetlands
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Assessment of the condition of San Francisco Bay Area depressional wetlands
State Water Resources Control Board | March 23, 2017...
Summary
Depressional wetlands are the most abundant, yet most threatened wetland type in California. Despite their relatively ubiquitous nature, they are poorly characterized, and...
Depressional wetlands are the most abundant, yet most threatened wetland type in California. Despite their relatively ubiquitous nature, they are poorly characterized, and unlike streams, they are not subject to any systematic ambient monitoring and assessment in California. Consequently, decisions regarding protection, restoration, and management, such as issuance of Section 401 water quality certifications or prioritization of projects for wetland restoration grant funding, are usually made without the benefit of any regional context of condition, knowledge of predominant stressors, or rigorous documentation of reference conditions.

The goals of this study were to apply tools for ambient monitoring of depressional wetlands in the San Francisco Bay region to accomplish the following: 1) To evaluate the regional condition of depressional wetlands in this portion of northern California, and 2) To evaluate the relationship between condition and stress by sampling both local stressors (intensity of direct wetland use, water chemistry, and sediment chemistry) and landscape stressors (adjacent land use, flow diversions, and road density). Once achieved, these goals should establish the foundation for developing a robust ambient depressional wetland monitoring program.

This study included perennial (have surface water year round) and seasonal (lack surface water for part of the year) depressional wetlands as defined by Brinson (1993) located within the boundaries of the San Francisco Bay Regional Water Quality Control Board. Depressional wetlands in this study includes both natural water bodies such as sag ponds and small lakes, as well as created wetlands such as abandoned or active stock ponds, aesthetic ponds, and irrigation/treatment ponds. Wetlands were not considered for this study if they were concrete lined, marine influenced, wastewater treatment ponds, livestock wastewater ponds, riverine (i.e., dominated by riverine hydrology), dry, or vernal pools. It is likely that a majority of wetlands sampled in this study would be considered waters of the State of California; the field teams did not perform a regulatory-based delineation of a wetland as part of this study.

Thirty wetlands in the San Francisco Bay area were sampled during the spring of 2014, including both perennial and seasonal wetlands. The proportion of wetlands in the region considered “likely intact” (scores in the upper 50th percentile of the range found at reference sites) varied by indicator.

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Bathymetry and Digital Elevation Models of Coyote Creek and Alviso Slough, South San Francisco Bay, California
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Bathymetry and Digital Elevation Models of Coyote Creek and Alviso Slough, South San Francisco Bay, California
U.S. Geological Survey (USGS) | March 15, 2018...
Summary
In 2010 the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center completed three cruises to map the bathymetry of the main...

In 2010 the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center completed three cruises to map the bathymetry of the main channel and shallow intertidal mudflats in the southern most part of south San Francisco Bay. The three surveys were merged to generate comprehensive maps of Coyote Creek (from Calaveras Point east to the railroad bridge) and Alviso Slough (from the bay to the town of Alviso) to establish baseline bathymetry prior to the breaching of levees adjacent to Alviso and Guadalupe Sloughs as part of the South Bay Salt Pond Restoration Project. Since 2010 the USGS has conducted twelve additional surveys to monitor bathymetric change in this region as restoration progresses.

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Carbon accumulation and vertical accretion in a restored versus historic salt marsh in southern Puget Sound, Washington, United States

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Carbon accumulation and vertical accretion in a restored versus historic salt marsh in southern Puget Sound, Washington, United States
Society for Ecological Restoration | March 4, 2019...
Summary
Few comparisons exist between vertical accretion (VA) and carbon accumulation rates (CARs) in restored versus historic (i.e. reference) marshes. Here, we compare these...
Few comparisons exist between vertical accretion (VA) and carbon accumulation rates (CARs) in restored versus historic (i.e. reference) marshes. Here, we compare these processes in a formerly diked, sparsely vegetated, restored salt marsh (Six Gill Slough, SG), whose surface is subsided relative to the tidal frame, to an adjacent, relatively pristine, historic salt marsh (Animal Slough, AS). Six sediment cores were collected at both AS and SG approximately 6 years after restoration. Cores were analyzed for bulk density (BD), % loss of ignition, % organic carbon, and ²¹⁰Pb. We found that sharp changes in BD in surface layers of SG cores were highly reliable markers for the onset of restoration. The mean VA since restoration at SG (0.79 [SD = 0.29] cm/year) was approximately twice that of AS (0.41 [SD = 0.16] cm/year). In comparison, the VA at AS over 50 years was 0.30 (SD = 0.09) cm/year. VA consisted almost entirely of inorganic sediment at SG whereas at AS it was approximately 55%. Mean CARs at SG were somewhat greater than at AS, but the difference was not significant due to high variability (SG: 81–210 g C m⁻² year⁻¹; AS: 115–168 g C m⁻² year⁻¹). The mean CAR at AS over the past 50 years was 118 (SD = 23) g C m⁻² year⁻¹. This study demonstrates that a sparsely vegetated, restored salt marsh can quickly begin to accumulate carbon and that historic and restored marshes can have similar CARs despite highly divergent formation processes.

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Case Studies of Natural Shoreline Infrastructure in Coastal California: A Component of Identification of Natural Infrastructure Options for Adapting to Sea Level Rise

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Case Studies of Natural Shoreline Infrastructure in Coastal California: A Component of Identification of Natural Infrastructure Options for Adapting to Sea Level Rise
The Nature Conservancy | November 27, 2017...
Summary
Sea level rise and erosion are major threats to California’s coast, requiring solutions to preserve the many benefits a healthy coastline provides: flood...

Sea level rise and erosion are major threats to California’s coast, requiring solutions to preserve the many benefits a healthy coastline provides: flood protection, recreation, habitat for wildlife, water quality and more. Seawalls and other engineered structures, are commonly installed in order to hold the shoreline in place and hold back the ocean; however, they ultimately make the situation worse in most cases by increasing erosion and thus causing already vulnerable shorelines to shrink more. Natural shoreline infrastructure is an alternative that is more likely to preserve the benefits of coastal ecosystems while also maintaining coastal access. The California coastline is very diverse, and no single solution will address all the chal- lenges anticipated in the future. While there is a continuum of approaches to address sea level rise and coastal erosion— ranging from fully natural approaches that preserve or restore natural systems, hybrid solutions that integrate engineered aspects into restored or created natural features, and fully engineered structures like seawalls and revetments—prop- erty owners and managers don’t typically consider the entire range of options when making coastal management decisions.

To address the gap in familiarity with natural infrastructure and the lack of technical guidance to aid decision-makers and engineers in the appropriate application of different strategies for different situations, this report summarizes natural infrastructure projects for a range of settings in coastal California. Each case study covers the background, permitting, planning, implementation, performance, and key lessons learned from each project in order to provide the critical information needed to implement successful adaptation strategies to address coastal issues, and inspire other communities by highlighting the lessons learned.

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Conserving California’s Coastal Habitats: A Legacy and a Future with Sea Level Rise

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Conserving California’s Coastal Habitats: A Legacy and a Future with Sea Level Rise
The Nature Conservancy | May 15, 2018...
Summary
The California coast that we know today will not be the coast of the future. Sea level rise and other climate change impacts...

The California coast that we know today will not be the coast of the future. Sea level rise and other climate change impacts will have profound effects on our coastline and its natural resources. California harbors high numbers of native, rare, and imperiled species in an array of unique coastal habitats. A majority of California’s coastline exists as natural habitat, over one-third of which has been preserved by a legacy of conservation efforts. Yet, this conservation legacy is at risk and we must act now to conserve the unique values of California’s coast—for both people and nature—into the future.

To inform current and future adaptation decisions and conservation actions we conducted the first statewide, comprehensive assessment of the vulnerability of California’s coastal habitats, imperiled species, and conservation lands to sea level rise. Coastal habitats exist in narrow bands at the land-sea interface and are therefore extremely susceptible to inundation by sea level rise. However, some habitats may be able to adapt vertically and possibly move inland, assuming local topography and the built environment do not constrain this movement. We assessed the vulnerability of 40 habitats to sea level rise by quantifying the sensitivity and spatial extent of projected exposure of each habitat patch to intertidal and subtidal waters, relative to its ability to move inland in response to rising sea levels.

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Age Determination of the Remaining Peat in the Sacramento–San Joaquin Delta, California, USA

Age Determination of the Remaining Peat in the Sacramento–San Joaquin Delta, California, USA

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Aluminum- and iron-based coagulation for in-situ removal of dissolved organic carbon, disinfection byproducts, mercury and other constituents from agricultural drain water

Aluminum- and iron-based coagulation for in-situ removal of dissolved organic carbon, disinfection byproducts, mercury and other constituents from agricultural drain water

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An Evaluation of Compensatory Mitigation Projects Permitted Under Clean Water Act Section 401 by the California State Water Resources Control Board, 1991-2002

An Evaluation of Compensatory Mitigation Projects Permitted Under Clean Water Act Section 401 by the California State Water Resources Control Board, 1991-2002

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Analysis of the costs and benefits of using marsh restoration as a sea level rise adaptation strategy in San Francisco Bay

Analysis of the costs and benefits of using marsh restoration as a sea level rise adaptation strategy in San Francisco Bay

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Applied Aquatic Science: A Business Plan for EcoAtlas

Applied Aquatic Science: A Business Plan for EcoAtlas

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Assessment of the condition of San Francisco Bay Area depressional wetlands

Assessment of the condition of San Francisco Bay Area depressional wetlands

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Bathymetry and Digital Elevation Models of Coyote Creek and Alviso Slough, South San Francisco Bay, California

Bathymetry and Digital Elevation Models of Coyote Creek and Alviso Slough, South San Francisco Bay, California

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Carbon accumulation and vertical accretion in a restored versus historic salt marsh in southern Puget Sound, Washington, United States

Carbon accumulation and vertical accretion in a restored versus historic salt marsh in southern Puget Sound, Washington, United States

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Case Studies of Natural Shoreline Infrastructure in Coastal California: A Component of Identification of Natural Infrastructure Options for Adapting to Sea Level Rise

Case Studies of Natural Shoreline Infrastructure in Coastal California: A Component of Identification of Natural Infrastructure Options for Adapting to Sea Level Rise

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Conserving California’s Coastal Habitats: A Legacy and a Future with Sea Level Rise

Conserving California’s Coastal Habitats: A Legacy and a Future with Sea Level Rise

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