The politics of Lake Koshkonong and the Indianford Dam have been contentious for more than 100 years.

A narrowing of the Rock River near Newville creates the big lake. But the dam, miles downstream from the lake, has a definite effect on it during dry times. During floods the dam doesn't change things at the lake at all.

Normally, the lake today is a big, shallow bowl with an average depth of perhaps 5 feet. But history shows that before the dam was raised to its present level, Koshkonong was a much different place.

The lake was much more shallow, and marshy. The marsh was filled with wild rice and wild celery. The thousands of canvasback ducks that came to eat those foods made Koshkonong one of the finest places to hunt ducks on earth.

But the dam and the destructive activities of carp, a rough fish introduced by the federal government, ended the days of wild rice and abundant ducks by the 1920s.

Even before that, though, some were complaining about what the dam had done to the lake. Farmers, weary of floods on their low-lying lands, tried to get a bill passed in 1878 to get the dam removed.

The dam had its champions. It provided power for downstream mills, and the businessmen who owned those mills prevailed in the Legislature.

Rock County bought the dam in the 1960s from Wisconsin Power & Light for $1, a purchase it has come to rue. This version of the dam, built in 1917, needs regular, expensive repairs.

And through the years, the county has been criticized by some who live on the lake for the way the dam has been operated. Sue Josheff, a dam safety engineer with the Wisconsin Department of Natural Resources, said that her department sometimes gets complaints on the same day that Koshkonong is too high and that it is too low.

Frank Micale, president of the Rock River-Koshkonong Association, blames Rock County for worsening the flood of 1996 by leaving the dam gates shut. But that summer, the lake got so low it was all but unusable, he says.

Boaters complain that they damage their propellers on the bottom of the shallow lake.

Marina owners call for a stable, happy medium. During dry years, the water can be 100 yards or more from what had been lakeside piers.

The county has been paying to preserve a dam for a lake that is mainly in Jefferson County. Jefferson County has paid nearly nothing to support the dam. And now, the DNR has ordered another round of repairs.

Frustrated Rock County officials have pointed out that they can choose to abandon the dam and have it removed. In June, Rock County Board Chairman Terry Maybee and Parks Director Tom Kautz delivered that threat to the Jefferson County Board.

Some scoff at the notion that Rock County will pull the plug on the dam that backs up the eighth biggest lake in the state. Others, like Jerry Richardson, a Newville marina owner, say they can't afford to take such suggestions lightly.

Jefferson County still has not committed to paying for maintenance at the dam. Some argue that Rock County deserves to pay the biggest share, because its share of the lake shoreline has the most expensive properties on the lake. All Rock County property taxes will rise, if the property values in Newville decline, they say.

The threat of dam removal has prompted Richardson and others on the lake to begin organizing a lake district. The district could tax its members to pay for improvements on the lake. The district won't buy the dam, though, Richardson said. And it won't pay for the bulk of repairs needed.

That leaves Rock County struggling to convince Jefferson and Dane counties to contribute to dam upkeep.