There are two sets of rapids on the Red Cedar, which is otherwise slow, flatwater. One is behind the Administration Building on the Michigan State University campus and is known as the MSU wave. Ordinarily a shallow section of ripples below an artificial underwater barrier, the wave appears at high water and becomes a play spot. The wave becomes surfable at about 800 cfs on the USGS Gauge. You can also check out the USWS page.
Here are some pictures of the wave in
February with Eric Olle braving the cold water.
WILLIAMSTON ARTIFICIAL RAPIDS
Built by the city of Williamston in 1998 to replace a breached dam, the Williamston rapids are a 100 yard stretch of class I that runs along one of the main streets of downtown. Parking is across the street from the rapids and the put-in is above the bridge where Putman street crosses the river. At the bottom of the rapids you can either take out on river left or carry your boat back to the top by walking along the island in the center of the river. A good level for adequate water without washing out the features is about 250 c.f.s./4 ft. on the East Lansing gauge. It is an ok rapids for beginners but suffers from three problems. First, the original project was never entirely completed and getting from the river back up to the boardwalk at street level is difficult. Second, no one seems to maintain the rapids and many of the "boulders" have been displaced. Third, and most important, the river is polluted with e-coli bacteria from sources above the Putman street bridge. Levels can be extraordinarily high at times. Paddle at your own risk.
The following link provides some historical information about the rapids and pictures of them.
Erik Carlson's page.