California’s Hill Slough Restoration Project complete

After years of planning and fundraising, the 649-acre Hill Slough Restoration Project was recently completed by Ducks Unlimited, in partnership with the California Department of Fish and Wildlife (CDFW).

“DU was brought into the tidal marsh restoration project in 2012 and finalizing the design and getting it through construction was no small feat,” said DU Regional Biologist Aaron Will. “The project helped raise Grizzly Island Road, the main entrance to Suisun Marsh, more than five feet over mucky soils, building access berms under Pacific Gas & Electric powerlines and re-enforcing a levee to protect a marina.”

The project also created a scenic loop trail around a protected seasonal wetland. Will said that while there have been several accidental levee breaches over the years, October marked the first time tidal waters entered the site for good since the 1930s. Brackish water now enters and leaves the site through 11 levee breaches.

Coastal ecosystems are among the most productive on Earth, rivaling tropical rainforests for biomass production. This project benefits threatened and endangered fish species and terrestrial species such as the Salt Marsh Harvest mouse.

DU partnered with the University of California at Berkley to conduct blue carbon science, using flux towers to measure greenhouse gases before and after restoration to measure carbon. Preliminary estimates say the project will sequester over 25,242 metric tons of Carbon Dioxide over the next 50 years, equivalent to taking 5,500 cars off the road for a year.

“The site will take some time to stabilize; however, waterfowl response to tidal flows in the short term has been better than expected. The site is being used by teal, gadwall, northern shovelers and mallards.” Will said.

Even though the site has open tidal access, the area is off-limits to hunters. Fishing is allowed. The project area also features interpretive panels along the new walking trail showcasing the history of the area, project benefits and information about wildlife that inhabit the site.

The Hill Slough project also improved another 192 acres of existing wetlands through construction of runoff channels and improved water-control structures. Funding for this $13 million restoration project was provided by California water bonds, CDFW, CDFW Greenhouse Gas Reduction Program via California Climate Investments, the Joseph and Vera Long Foundation, the Damage Assessment and Restoration Plan for the Kinder Morgan/Suisun Marsh Spill funds and private contributions.

Ducks Unlimited Inc. is the world's largest nonprofit organization dedicated to conserving North America's continually disappearing waterfowl habitats. Established in 1937, Ducks Unlimited has conserved more than 15 million acres thanks to contributions from more than a million supporters across the continent. Guided by science and dedicated to program efficiency, DU works toward the vision of wetlands sufficient to fill the skies with waterfowl today, tomorrow and forever. For more information on our work, visit www.ducks.org.