Archive for Tuesday, March 26, 2002

s quake threshold under debate

March 26, 2002


— Homeowners and business leaders whose lakefront views and livelihood depend on the Tuttle Creek dam are divided about what, if anything, should be done to make it able to withstand a high-magnitude earthquake.

The Tuttle Creek dam near Manhattan, built 40 years ago, is just 12 miles from the Humboldt fault, which produces major quakes once every 2,000 years. And the Army Corps of Engineers has become concerned that a quake could destroy the dam and flood much of Manhattan, endangering 14,000 people.

Solutions to fix the problem range from replacing or enlarging the dam at a cost of $250 million, or doing nothing. Dam construction would take five to 12 years and could require that the lake be lowered, leaving hundreds of lakeside homes far from the water and costing the area about $22 million a year in tourism.

The corps could minimize the risks of the dam  but not completely fix the problem  by restricting lake levels, improving seepage control, improving emergency planning, improving the ability to drain the lake, or better managing the floodplain downstream, officials said.

The corps is expected to announce its proposed plan for addressing the risk on April 16.

The state Department of Wildlife and Parks fears that construction equipment and the lack of water would shut down the popular Tuttle Creek park for close to a decade and destroy the only year-round trout fishing stream in the state.

And drawn-out work could cost the state $4 million in park fees from the 500,000 annual visitors, Mike Hayden, secretary of the Department of Wildlife and Parks, said earlier this month.

Also concerned is the Kansas River Water Assurance District, which wants the current water flow from the dam maintained. The group of six cities owns storage space in the reservoir and depends on releases from the river to dilute the river's salty water.

The city of Manhattan and the Manhattan Chamber of Commerce both oppose removing the dam or permanently lowering the lake. But neither has found a solution that would balance public safety concerns and economic development.

More emergency planning is expected regardless of the solution. The corps has talked to Riley County about installing sirens or public address systems that would boom out instructions on how to evacuate should the dam fail.

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