The final phase of the 850-acre Hill Slough Tidal Restoration Project kicked off on Oct. 5 with the first of 11 levee breaches.
Located on California Department of Fish and Wildlife’s (CDFW) Hill Slough Wildlife Area, just south of Suisun City in Solano County, the project site is currently a collection of diked ponds and upland habitat adjacent to existing tidal marsh on the east, south and west sides. When completed this fall, the project will help create a contiguous tidal marsh of approximately 2,860 acres.
CDFW’s goal for the project is to restore natural hydrologic processes to aid in the recovery of listed plant and wildlife species such as the federally endangered soft bird’s-beak, Suisun thistle and California Ridgway’s rail. Additionally, scientists aim to provide tidal marsh habitat to offset loss from lower water levels and flow during drought years.
The project restores 603 acres of managed seasonal wetland and 46 acres of upland to tidal wetland for a total of 649 acres of restored tidal marsh. Restoration objectives will be achieved by creating eight external and three internal levee breaches, lowering portions of some levees and recontouring the interior of one pond. The project has also improved another 192 acres of existing mixed wetlands and uplands through the addition of a swale and new water control structures.
Recreational additions include a two-mile loop trail with interpretive signs and a public bench with views of the marsh. Trail access is just south of Suisun City and connects to Suisun City’s Grizzly Island Trail. Grizzly Island Road, which bisects the project and is owned by Solano County, was raised to prevent tidal overtopping and widened to add bicycle lanes.
The project is part of the California EcoRestore Initiative. Funding was obtained through California water bonds, Suisun Marsh Mitigation Agreement funds, the Damage Assessment and Restoration Plan for the Kinder Morgan/Suisun Marsh Spill funds, The Joseph and Vera Long Foundation, and California Climate Investments.
Special thanks go to Ducks Unlimited, Maggiora & Ghilotti Inc., Marsh Rat Tractor and Solano County Resource Management.