• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Decreasing Water Level at Eagle Lake Raises Concern

Posted on: Tuesday, 16 August 2005, 15:00 CDT

Town of Eagle After a dry summer and the continuing increase in the number of private wells in the area, Eagle Spring Lake Management officials are raising concerns about the lake's decreasing water level.

The 311-acre lake, which is created through an impoundment in the Mukwonago River, is considered one of the cleanest and the most biologically diverse small river systems in the state, according to Scott Thompson, director of conservation for eastern Wisconsin at the Nature Conservancy in East Troy.

The conditions provided by the river allow many mussel and fish species to flourish, and it is home to some threatened and endangered species, he said.

The lake level has been declining since spring. Problems with the water level were noticed when the dam would be opened to keep the lake within the 3-inch range of the level set by the state Department of Natural Resources, said Tom Day, chairman of the Eagle Spring Lake Management District.

"What we used to observe was that the water level would gradually rise because of the water coming into the lake," he said.

In spring, though, officials started noticing that when the dam is opened, the lake's water level "does not work its way back up," Day said.

The lake's water level is maintained by a dam that is never fully closed and is adjusted to allow either more or less water out to keep the lake within its range.

Officials are researching three theories as to why the level has changed.

The first theory, and the most likely cause, is the drought conditions in the area, Day said.

Another theory is that the private, shallow wells that have been added in the area as more subdivisions develop have put more stress on the aquifer, where the Mukwonago River gets some of its water.

So far, there is no obvious indication that the water-level drop can be attributed to wells, Day said. "We're not aware of any private wells having any trouble. We're not finding wells in our area are going dry."

University of Wisconsin-Madison professor Jean Bahr, from the department of geology and geophysics, is doing her own research on the Mukwonago River system. She said that about 70% of the water in the river upstream from the lake is from groundwater.

With further research, she will attempt to determine from what part of the aquifer water is originating. If the water originates from the gravel and sand portion of the aquifer rather than the lower bedrock portion, shallow wells could potentially decrease the amount of groundwater that goes into the river and the lake, she said.

The third theory suggests that beavers, which are abundant along the river system, have built a dam that is causing less water to flow down the river. Day said that theory is the most unlikely, though it has happened in the past.

In addition to researching the low water levels, the lake management district and the Nature Conservancy are seeking the causes of temperature changes in the lake. That research will help determine the long-term effects on the species that live in it.

The research is funded by a grant from the state that will allow the district to spend about $4,000 a year for the next three years.

"Species require a specific habitat and a certain amount of water to come through the system" to survive, Thompson said.

With the lower water levels, rises in temperatures in the lake and along the river have been seen, and those changes could have adverse effects on species that will not be known for years, he said.

The Eagle Spring Lake Management District will meet at 7:30 tonight and is expected to discuss the water levels.

Copyright 2005, Journal Sentinel Inc. All rights reserved. (Note: This notice does not apply to those news items already copyrighted and received through wire services or other media.)

Source: Milwaukee Journal Sentinel

More News in this Category