HORSESHOE LAKE DAM, SPILLWAY SHOULD BE COMPLETE IN SUMMER; PROJECT TO ENABLE LAKE DEPTH OF 3 FEET OVER MAXIMUM NOW

OLIVE BRANCH, Ill. -- The new Horseshoe Lake dam and spillway area is taking shape.

Construction is continuing for replacement of a deteriorating spillway at the southeast end of the 2,400-acre shallow lake, with completion of the project expected by summer.

"The new spillway is being constructed so that sometime in the future it could accommodate a lake elevation to 324 feet," said Gary McCandless of the Illinois Department of Coservation's engineering division. "That's about 3 feet over the current maximum elevation. But this won't be any immediate thing; we're still studying the overall report," said McCandless.

Prior to determination on whether the lake level should be raised, the department will conduct a variety of other studies concerning water oxygen levels and sediment in the lake. Additional studies will be conducted on tupelo and cypress trees in the lake and area, natural heritage species, archaeology and hydrology.

Plans for the dam and spillway were unveiled in July 1991, following a design study and dam rehabilitation project, said Sen. James F. Rea of Christopher, who was a leader in obtaining funding for the spillway dam project.

"About three years ago a group approached me about the silt problem at Horseshoe," said Rea. "We held a meeting at that time, in July of 1989, to discuss the problems and ways that the water level could be raised."

The conservation department hired a firm to conduct a design study for a dam rehabilitation project, which could be used to prevent flooding on adjacent land if the lake's depth was increased.

"We added $1.5 million to the capital-development-for-improvements category in the state budget," said Rea.

The new dam will have the same crest elevation as the one it will replace, and the new structure will also have two 4-by-5-foot sliding gates that will enable better management of the lake.

"The present dam does not have the gates," said Rea. "The plans also calls for additional concrete work at the spillway area. The plans also call for a 40-foot timber-deck pedestrian bridge to be located downstream from the dam."

The new spillway will have about 60 feet of length available, but only 36 feet will be used for waterflow at this time, said McCandless.

McCandless and a number of other Illinois Department of Conservation officials discussed Horseshoe Lake and a problem concerning sedimentation in the lake during a recent meeting at Olive Branch.

"Horseshoe Lake is a shallow lake," said Jim Mick of the department's fisheries division. "The lake is currently losing its capacity at the rate of about 0.5 inches per year, which is resulting in a major loss of fish habitat."

Mick explained that the process has also increased fish kill potential. He explained that a winter kill could occur from ice cover causing oxygen depletion. Due to the shallowness of the lake about five feet in its deepest part ice, with 4 to 6 inches of snow, could result in a complete fish kill, he said.

Mick said that during the summer a fish kill could occur following several days and nights of hot, calm, cloudy weather with night temperatures in the mid-80s.

"Several severe fish kills have occurred in the last five years in portions of the lake," said Mick. "It appears that Horseshoe no longer has sufficient depth, due to sedimentation problems, to insure that winter and summer fish kills will not happen."

The state, in its study of the lake, suggests some alternates for reducing the sedimentation.

"A detention basin is the most effective alternate," said Mick. "This will provide the largest sediment reduction, and is about twice as effective as the land treatment (watershed)."

Horseshoe, which got its name from its horseshoe shape, is near Olive Branch in Alexander County. The lake has a 20-mile shoreline with a maximum depth of about 6 feet. It is a favorite fishing spot for many anglers. It also is home to wintering Canada geese. As many as 200,000 wild geese flock into the Horseshoe area each winter.