Simmons Slough - (Cheng)

Status Completed County Marin
Project Type Non-mitigation Location Not Mapped
Project Area (Acres) 37.90 Last Updated 11 March 2019
Project Abstract This project expanded and enhanced seasonal wetlands for birds and other wildlife. Activities included excavating 24,000 cubic yards of fill and rubble to expand seasonal wetlands, grading the slopes 10:1 to create a transition zone, burying debris on site below clean surface material and revegetating the upland with native species.

Project Identification

728 JV - Record Number

Habitat Plan

ActivityHabitatSubHabitatAcresActivity StatusWater Regime
Acquisition/Preservation/Protection Seasonal Wetland Floodplain 19.00 Completed Seasonal non-tidal
Enhancement Seasonal Wetland Floodplain 17.00 Completed Seasonal non-tidal
Restoration Seasonal Wetland Floodplain 1.90 Completed Seasonal non-tidal

Related Habitat Impacts

HabitatAcres LostType of Loss
No Data


Simmons Slough - (Cheng) Completed 37.90


DateTypeDescriptionSite Name
2012-01-01 Other This property was deeded to the Marin County Open Space District in 2012 and remains in their ownership.
2008-10-15 Project end date
2008-06-01 Project start date
2002-06-01 Other Parcel was acquired with funding from the MCOSD, SCC, and assistance from donors to the Marin Baylands Fund at the Marin Community Foundation.


Contact Barbara Salzman Marin Audubon Society Not applicable/Unknown


Acquisition/Preservation/Protection Marin County Open Space District
Acquisition/Preservation/Protection SCC State Coastal Conservancy $302,000
Restoration Unknown/Unspecified Private Funder $125,000
Acquisition/Preservation/Protection Marin Baylands Advocates $19,603

Related CRAM Assessments

Visit DateVersionSite NameWetland TypeIndex Score
No Data
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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.

Display Habitat Development Curves For Wetland Type:

CRAM Site Scores