Sonoma Creek Tidal Marsh Enhancement to Improve Habitat and Water Quality

Status In-progress County Sonoma
Project Type Non-mitigation Location 38.14026° N, -122.40516° W Map
Project Area (Acres) 260.0 Last Updated 11 October 2019
Project Abstract The Sonoma Creek Enhancement Project was designed to enhance tidal fluctuation and habitat functionality in 260 acres of the Sonoma Creek marsh. Goal is to improve water quality, reduce application of mosquito pesticides, improve habitat for Ridgway's Rails and Salt Marsh Harvest Mice, and improve resiliency to sea-level rise.
Project Groups San Francisco Bay Restoration Authority (Eligible) | SFBJV Subregion - North Bay

Project Identification

615 JV - Record Number

Habitat Plan

ActivityHabitatSubHabitatAcresActivity StatusWater Regime
Enhancement Bay Habitat (SFBJV Only) Tidal marsh 260.0 Construction in-progress Fully tidal

Related Habitat Impacts

HabitatAcres LostType of Loss
No Data


Sonoma Creek Enhancement Project In-progress/Implementation 260.0


DateTypeDescriptionSite Name
2018-08-14 Site visit Staff from the San Pablo Bay National Wildlife Refuge (Refuge), Marin-Sonoma Mosquito and Vector Control District (District), and Gillenwater Consulting visited the Sonoma Creek Marsh Enhancement Project site on August 14, 2018 to review the locations of proposed adaptive management actions to confirm field conditions, construction feasibility and approach, and equipment/staff needs for implementation. Sonoma Creek Enhancement Project
2018-06-01 Permit As of June, 2018, all permit extensions were secured. This includes the Clean Water Act Section 401 and 404 Certifications and Consistency Determination No. C2OI4.OO4.00 from BCDC. Construction is authorized until March 18, 2022.
2015-11-30 Groundwork end Construction of project features was completed, but only partially completed due to funding limitations. Sonoma Creek Enhancement Project
2010-11-22 Project start date


Contact Andrea Jones Audubon California Not applicable/Unknown
Contact Rebecca Schwartz Lesberg Audubon California San Francisco Bay Program Director


Funding Need: $1,390,000

Enhancement USFWS San Pablo Bay National Wildlife Refuge
Enhancement National Audubon Society
Enhancement USFWS National Coastal Wetlands Conservation Program $1,000,000
Enhancement WCB Wildlife Conservation Board $700,000
Enhancement U.S. Environmental Protection Agency $235,884
Enhancement SCC State Coastal Conservancy $200,000
Enhancement National Fish and Wildlife Foundation $175,000
Enhancement Marin-Sonoma Mosquito and Vector Control District $88,000

Related CRAM Assessments

Visit DateVersionSite NameWetland TypeIndex Score
2007-12-11 5.0.1 Hwy 37 west estuarine perennial saline 71
Upload files or links
Name File Type Submitted On Submitted By
Final Project Report Monitoring Report 2018-02-01 Julia Kelly, Audubon California
Sonoma Creek Enhancement Project Other 2017-11-27 Liz Duffy, SFBJV

How to Use the Habitat Development Curve

Habitat Development Curves (HDCs) are used to determine the developmental status and trajectory of on-the-ground projects to create, restore, or enhance California wetland and stream habitats. Each HDC is based on assessments of habitat condition for different age areas of one habitat type that in aggregate represent the full spectrum of habitat development. The assessments of condition are provided by expert applications of the California Rapid Assessment Method (CRAM). Visit the CRAM website for more information about CRAM.

For each HDC, reference condition is represented by areas of a habitat that consistently get very high CRAM scores, have not been subject to disruptive management practices, and exist within landscapes that are protected and managed for their natural conditions. The horizontal lines intersecting the top of an HDC represent the mean CRAM score and standard deviation of scores for 25 qualifying reference areas.

The age of a project is estimated as the elapsed time in years between the groundwork end date for the project and the date of the CRAM assessment. To add or update a groundwork end date, use the Project Events form in Project Tracker ( The minimum age in years of a non-project area, including any natural reference area, is estimated from all available local information, including historical maps and imagery, historical written accounts, and place-specific scientific studies of habitat development.

An HDC can be used to address the following questions:

  1. At what time in the future will the area of assessed habitat achieve the reference condition or other milestones in habitat development? The HDC can answer this question if the CRAM score for the assessed area is within the confidence interval of the HDC. The answer is the time in years along the HDC between the current age of the assessed area and the future date corresponding to the intersection of the HDC and the reference condition or other milestone.
  2. Is the area of assessed habitat likely to develop faster, slower, or at the same pace as most other areas of the same habitat type? The habitat area is likely to develop faster, slower, or at the same pace if the CRAM score for the area is above, below, or within the confidence interval of the HDC, respectively.
  3. What can be done to improve the condition of the habitat area or to increase its rate of development? HDCs by themselves cannot answer this question. Possible answers can be inferred by the following analysis that involves HDCs:
    1. Examine the HDC for each of the four CRAM Attributes;
    2. Identify the Attribute(s) scoring below the HDC;
    3. For any low-scoring Attribute, examine the component Metric Scores (note: the Metric Scores for any public CRAM assessment in the CRAM database can be obtained through EcoAtlas);
    4. Assume the low score of an Attribute is due to its low-scoring Metric(s);
    5. Consider modifying the design or management of the habitat area in ways that will sustainably increase its score(s) for the low-scoring Metric(s).

For more information about CRAM Attributes and Metrics, including their scientific rationale, see the CRAM Manual.

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