Little Rapids Habitat Restoration

PROJECT SUMMARY

The Rapids habitat on the St. Marys River has been impacted by various forms of development, including dredging, filling and diversion, and urban development.

Prior to the launch of this project, the main rapids was the only location that still functioned as a rapids. The St. Marys River was listed as an Area of Concern (AOC) by several groups due to its degraded water quality and associated impaired beneficial use of the river.

In order to restore flow to the historic rapids area, the Sugar Island Causeway required a box culvert or bridge structure to be installed. This Design-Build project was a joint effort with Payne and Dolan providing engineering, grading, and asphalt paving and Zenith Tech performing the structural construction.

First, the technical concepts for the box culverts and various bridge lengths were prepared and it was found that a 625-ft bridge span with 609-ft of clear opening would be the most cost-effective solution for restoring flow to the Little Rapids area of the St. Marys River. This solution met all of the design criteria set forth for the project.

The bridge is 40-feet wide to allow for two 11-foot lanes, 4-foot shoulders, and a 5-foot pedestrian/fishing access area. Approximately 400-feet of roadway at each end of the bridge was reconstructed to match the new bridge elevation and to accommodate parking for fishing access on both ends of the bridge.

To maintain public access during construction and material delivery, a temporary causeway was designed and constructed allowing for construction access, a staging area for construction of the new bridge, and public traffic.

SERVICES

• Roadway Design
• Permitting (ACOE, MDEQ, Chippewa County)
• Roadway & Bridge Construction