GEI has helped the City of Corunna secure more than $400,000 in grant funds to take out the Corunna dam on the Shiawassee River. GEI and the city are also working to secure an additional $300,000 to design and construct a boardwalk, overlook and other park improvements along the site of the dam removal.
The Corunna Dam removal will result in 12 additional miles of upstream access on the mainstem of the Shiawassee and an additional 134 miles of upstream access on tributaries to the mainstem of the river. Together with the Shiatown Dam removal that GEI is also working, the work will result in new access to 31 Shiawassee River mainstem miles and access to a total of 169 tributary miles. GEI is responsible for design, wetland, tree, Indiana bat habitat and mussel surveys and relocation, permitting, construction oversight and assisting with public education and outreach.
For Corunna Dam, the GEI design will completely remove the 6-ft dam structure, along with stabilizing and narrowing the channel to reference reach conditions and installation of J-hook and toe wood structures to provide habitat diversity. GEI is also working on preserving a portion of the millrace as an historical reference point to the dam’s former uses.
Following project initiation, GEI was able to help the City of Corunna also secure MI DNR Trust Funds to add a boardwalk, overlook, kayak and canoe launch and trail connection to final design. Because impoundment sediment sampling found fine sediment pollutant exceedances for human exposure around fringe areas of sediment to be exposed following drawdown, GEI worked closely with Michigan Department of Environment, Great Lakes, and Energy (EGLE) to develop a plan to manage that sediment in-place with a form of conservation easement.