A New Bridge And Better Habitat Along The Mississippi River

Turn off of Hwy 61 into St. Paul Park, and drive past the Masonic Lodge and then the American Legion. Head south out of town and you’ll eventually find yourself rolling past farms in a seldom-visited corner of the county, hemmed in on the west and south by the Mississippi River. Grey Cloud Township occupies the upper of two islands in the river, separated from the “mainland” by Mooers Lake and the Grey Cloud Slough. This tiny township, with only 10 square miles of land and 125 households, is also the location of Washington County’s newest bridge.

A view of Mooers Lake from the Grey Cloud Scientific Natural Area (actually located in City of Cottage Grove). Grey Cloud Island is separated from the rest of Washington County by the Grey Cloud Slough and Mooers Lake, which are part of the Mississippi River.

Though Grey Cloud Island is hard to access by modern standards, people have lived there for more than 2000 years. According to the Washington County Historical Society, the island has a large concentration of Indian mounds, built by woodland mound-builders between 100 BC and 600 AD, and was home to people of the Late Mississippian culture around 1000 AD. Mdewakanton Sioux also lived there during the 1800s until white settlers moved in and began establishing farms. In 1856, three of these settlers platted the future Grey Cloud City, advertising “400 lots, a good steamboat landing, and a view of the river.”

Though Grey Cloud Island never became a city, the settlers did build wooden bridges across the Grey Cloud Slough so that wagons hauling wheat could reach Newport, Cottage Grove, Afton and Port Douglas. Eventually, in 1923, the wooden bridge at the north end of the island was replaced with culverts and filled over to create County Road 75. All was well until the 1960s, when back-to-back floods washed loads of sediment and debris into the culverts under the road, turning what was once a bridge into a dam, and what was once a meandering backwater channel into a dead-end slough filled with stagnant water.

The above map shows the location of the bridge to Grey Cloud Twp. Poor water quality in Grey Cloud Slough and excess algae growth are apparent in the aerial imagery.

This fall, Washington County and South Washington Watershed District are constructing a new bridge in Grey Cloud Township that will finally restore the natural water flow in Grey Cloud Slough and help to flush out sediment and nutrients that have accumulated over the past 50 years. The total project will cost $1.8 million, with funding provided by Washington County, the South Washington Watershed District, and funds appropriated by the State Legislature from the Clear Water Fund.

In September, crews worked to install footings for the new bridge.

The new bridge will serve a practical purpose, but the primary impetus behind the project was to improve habitat and water quality in the Grey Cloud Slough. The area is part of the Mississippi National River and Recreation Area, which is in the National Park System, and is also a designated Minnesota State Water Trail. Within Washington County, there is already limited public access to the Mississippi River, and the nearest public boat launch to Grey Cloud Island is at Lion’s Levee in St. Paul Park. Without a way for canoers, kayakers, and other boats to pass under Hwy 75, however, the slough has been mostly inaccessible since the 1960s.

Replacing the blocked culverts with a bridge will provide immediate water quality benefits by allowing water to flow freely again. Fish and turtles will be able to travel through the channel and there will be less algae and sediment in the water. In addition, South Washington Watershed District and local non-profit Great River Greening hope to work with private landowners along the Grey Cloud Slough to restore two miles of shoreline and 100 acres of aquatic habitat once the bridge is complete.

The new bridge in Grey Cloud Township is expected to open by the end of October. See photos of the progress on-line in real time at https://app.oxblue.com/open/WC/CR75. Learn more about the South Washington Watershed District at www.swwdmn.org.

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