The problems with the spillway at Lone Star Lake, if not corrected, could lead to a breach of the dam and a "devastating-type" flood, the county's public works director says.
The Kansas Division of Water Resources has ordered Douglas County to come up with a plan for repairing the spillway at Lone Star Lake, citing public safety concerns.
In a letter county commissioners received Monday, chief engineer David L. Pope said an inspection "revealed that only one concrete retaining structure (of three) remained competent in the spillway of the dam. This remaining concrete structure is undermined due to spillway flows."
And that's a public safety hazard, Pope said.
"Therefore you are hereby ordered to immediately take corrective action that consists of a schedule for implementing such action pre-approved by the chief engineer," the engineer said in his letter. "Corrective action shall include preparation of an acceptable emergency action plan that provides for the safety of all potentially affected life and property downstream."
Commissioner Dean Neider said that about 18 to 24 cabins are on the lake; some of the cabins are occupied year-round, others are occupied only on weekends.
In response to the state report, the county may lower the lake an additional three feet and keep it below its winter pool level until the spillway can be repaired, Public Works director Keith Browning said.
That means waterskiing, swimming and boating could be undermined next summer.
Browning estimated repairing the spillway will cost about $1 million.
That's no small chunk of change, but commissioners on Monday voiced support for spending it and possibly raising the money through a sales tax passed in 1994 and earmarked for the new jail and the joint city-county health building. Permanent funding has not been secured for those projects, so the cost could be spread out further to help with paying for the spillway, County Administrator Craig Weinaug said.
A spillway, Browning said, essentially "carries away excess water. A dam is designed to restrain so much water, and when there's more water than that, it has to go somewhere so a spillway is a controlled way to disperse the excess flow."
The woes could eventually result in a breach of the dam, Browning told commissioners.
"There'd be a sudden opening of the dam that would release a lot more water from the dam than would ordinarily be released," Browning said later.
The Lone Star area has flooded three times in the last few years, but if the dam breached, "it would be a more devastating-type flood," Browning said. "It would be fairly quick."
County officials have known for years about the problem and in 1989 hired a consultant to look at ways to fix it. Three alternate designs for replacing the spillway were mapped out, but the project never was funded.
Now there's no choice, commissioners said Monday.
Commission Chair Tom Taul tossed out a big question -- "What if the lake wasn't there?" The county is under no obligation to keep the lake, he noted. But Nieder, who lives near Lone Star, turned to Commissioner Mark Buhler and asked him what would happen to property values if the lake were drained.
They'd probably fall 50 percent "or worse," Buhler said.
The public works department should be able to use the 1989 study as a basis for design.
Meanwhile, lake enthusiasts likely will be disappointed come summer, Browning said.
Recreational use of the lake will be greatly diminished, he said. The county does not keep numbers on visitors to the lake, but it issued 1,600 permits for boating, fishing and camping last year.
-- Deb Gruver's phone message number is 832-7165. Her e-mail address is firstname.lastname@example.org.