Hundreds of fish have died at Buffalo Park pond in west Wichita because of lack of water, and the city expects the toll to climb to about 1,000.
Three factors have contributed to the kill, said Doug Kupper, the city's parks and recreation director.
The pond, near Central and Maize Road, has been leaking from the bottom and suffering from an invasive plant that has been removing oxygen from the water for a couple of years. Recent hot weather has evaporated more of the water, he said.
Temperatures over the last couple of days have accelerated the kill, Kupper said.
The city has begun removing the dead fish and will continue as the pond dries.
The city is allowing the pond to drain completely to find leaks in the bottom and to destroy the invasive plant, called Eurasian water milfoil, Kupper said.
The city explored catching and moving the fish to another body of water, he said, but that would have infected their new water with the invasive plant.
Kupper said the city plans to repair the leaks once it determines where they are, and the state will restock the pond with fish.
The pond is operated in partnership with the Kansas Department of Wildlife and Parks.
Kupper said the goal is to re-open the park for fishing in 2012. He couldn't give a cost estimate for renovation of the pond.
The city found a leak in the pond about two years ago when it discovered water running out through an old pipe left over from when the pond was a sewage lagoon.
The city plugged the leak and thought the problem had been corrected, but the issue was disguised by unusually wet summers that kept the water level up, Kupper said.
The presence of the invasive plant was discovered at about the same time as the leak. The city has treated the pond with chemicals twice without any significant success, he said.