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Project Update: Sonoma Creek Marsh Enhancement

March 2016

With a tight time frame of just 4 months, a restoration team led by Audubon California, USFWS San Pablo Bay National Wildlife Refuge and Marin/Sonoma Mosquito Vector & Control District contracted local environmental engineers from Wetlands and Water Resrouces, Inc. (now part of Environmental Science Associates) and environmental construction specialists Hanford Applied Restoration & Conservation to start and complete the construction portion of the Sonoma Creek Enhancement Project during the fall of 2015.

In order to access the project area and perform the work, 1 mile of temporary road had to be constructed into the existing and degraded 400 acre tidal fringe marsh habitat. The construction included 3 main features:

  1. A tidal channel which is 4,560 feet long by 50 feet wide and 7 feet deep at its connection point to Sonoma Creek and required an estimated 40,000 cubic yards of material from the marsh;
  2. Refuge islands along the main channel for wildlife use in high tide or storm events; and
  3. A 9 acre (approx) transition ramp zone, with a gentle slope (40:1) allowing wildlife a place to seek refuge during high tide and extreme weather events.

The Sonoma Creek enhancement project is one of the first permitted projects allowing beneficial fill in a degraded marsh habitat around the Bay Area to incorporate recommended design features designed to prepare habitats for resiliency in an era of more frequent, higher intensity storm events and sea level rise from climate change. The 40:1 transition ramp feature was one of the first of its kind and addressed the need for high tide refugia needed for survival by wildlife when the marsh is inundated.

The team was able to share their projects’ successes at a Sonoma Creek Ceremony Event in early December and will be inviting their grantors out to see the completed project in early 2016.

Click on images to enlarge

Photos courtesy CA Audubon

Sonoma Creek Marsh Enhancement Sonoma Creek Marsh Enhancement

You can find more information about the project here and more photos of the project here.

For more information on this project visit our Sonoma Creek Marsh Enhancement project archive page.