Powell Falls. One of a half dozen dams at old water-powered mills from the 1800s. The mills are gone. Some dams are have been converted to producing hydroelectricity but at a cost to native trout and other other aquatic life.

A sense of the public good shifts over 1-1/2 centuries

RIVER FALLS, Wis. – The Army Corps of Engineers wants to take out one if not two dams on the Kinnickinnic River but wants public input first. The Corps has scheduled a hearing August 15 at the River Falls library, 140 Union Street, at 6 p.m. The Corps said the dams have degraded the Kinnickinnic’s once-bountiful trout habitat with sediment accumulation. At issue:

> Powell Falls Dam. Built in 1909 at the site of an old timber dam that backed up a millpond. The am was restored in 1940 to generate hydroelectricity. The design is a concrete gravity dam, 110 feet long and 22 feet high. The reservoir, Lake Louise, is 15.4 acres.

> Junction Falls Dam. Built in 1920 at the site of an older dam at a mill. It’s half a mile upstream from the Power Falls Dam. It also was restored in 1940 for hydroelectricity. It’s a 140-foot concrete gravity dam. The reservoir, Lake George, is 16 acres.

The Corps said that removing the dams could help protect aquatic resources. Under the federal Clean Water Act, the Corps works with state agencies on sustainability projects. The Corps said its own feasibility studies are at an early stage. Costs and benefits have yet to be calculated.

Before the mills. Before the damming.

Kinni fishery

The Kinnickinnic River, called “the Kinni” for short, is a 22-mile tributary to the St. Croix and Mississippi rivers. Although still designated a Class 1 trout stream, the river suffers degradation from impounded sedimentation.