Ecological impact of ruptured Tempe Town Lake dam could last for years

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TEMPE, Ariz. -- In the wake of Tuesday night's dam break, there's a fishy situation going on at Tempe Town Lake. The ecological impact of the ruptured dam and suddenly drained lake could resonate for years, according to marine biologists.

Javier Soto talked to Eric Swanson of the Arizona Game and Fish Department about what's happening with the tens of thousands of fish that were in the lake.

Swanson said most of the fish were swept downstream when one of the rubber bladders of the dam split at a seam Tuesday night, but there could be as many as 10,000 fish remaining in the drying bed that used to be Tempe Town Lake.

"Unfortunately, we're unable to salvage those because of the high temperatures and rapidly dropping oxygen, and the large scale and scope of the situation," Swanson explained.

Plans are in the works to remove the dead and dying fish to reduce odor and diminish any potential health hazards.

While it might look like easy pickings, officials with both Tempe and Game and Fish are encouraging people to avoid fishing at the lake right now.

Another issue with the drained lake is the possibility that the standing water will attract mosquitoes infected with the West Nile virus. It was announced earlier this month that the virus has killed one person; nearly a dozen more -- mostly in the East Valley -- have tested positive for it.

The city of Tempe said it is taking steps to mitigate that danger.

The other big concern is the possibility of the dead fish attracting birds, especially considering the lake's and river bed's proximity to flight paths in and out of Sky Harbor International Airport.

"Sky Harbor is very aware of the situation," Swanson said.

He explained that biologists will be closely monitoring the situation like they do every time the lake spills over and fish are carried downstream.

"Those crews are out there monitoring those ponds, removing those fish so they don't create an attraction for things like buzzards and turkey vultures that might come in, feed and then get up in the areas where airplanes are taking off," Swanson said.

Swanson said the mechanisms for dealing with the aftermath of a situation like a dam breach have been in place for several years.

Early estimates put the economic impact of the ruptured dam and drained lake at about $250,000.

Tempe hopes to have the lake back open by November. One of the lake's biggest events -- the Arizona Ironman Triathlon -- is scheduled for Nov. 18-22. The hope is to have the dam repaired and the lake filled in time for that event.