Cleaning up Allen Creek

continued

dollar effort, with 40 percent of the bill paid by a federal stimulus grant.

It aims to improve water quality in the Huron River by intercepting one of its tributaries, Allen Creek--which passes through the corner in an underground pipe. The creek was one of the defining natural features of Ann Arbor. City cofounder John Allen sited the town along its banks, and the configuration of Liberty, Miller, and Huron streets traces the high ground between its main branches. But it gradually devolved into an all-purpose drainage ditch and, beginning in 1925, was redirected into underground pipes.

"When the creek was first buried, the pipes were able to handle the amount of water that came through, most of the time," explains Harry Sheehan, environmental manager for the Water Resources Commission. "But just look at the west side of Ann Arbor, and see what's been developed since the 1920s. Behind Westgate and Maple Village shopping center, that's pretty much the top of the drainage area. Where there was once open land, now there's just a lot of pavement. The Allen Creek watershed is somewhere around 40 to 45 percent impervious--it's paved over, or it's rooftops or parking lots. The pipe that was buried in 1926 didn't account for all that."