Missoula Storm Drain Creates Floodplain in Homeowner’s Backyard
While the city of Missoula works on installing a $220,000 hydrodynamic separator to filter out storm drain water before it goes into the Clark Fork River, residents on the hill above Cold Springs Elementary are concerned about a project that the city hasn’t paid much attention to for decades. Missoula County Floodplain Administrator Todd Klietz says a storm drain system has created an oddly located floodplain on a hillside.
"That storm drainage is resulting in, at least since 1988, mandatory flood insurance for people that live down gradient of this storm drain," Kleitz said. "There's less than a dozen homes that are affected, but those that are affected have the requirement to carry federal flood insurance on their property if they have a federal mortgage on their property and also to comply with any floodplain regulations that both the city and the county have."
The floodplain insurance is pricey, up near $1,000 per year for some of these homeowners. The real surprising thing is where the storm drain system empties out… not far from a child’s swing set.
"It empties out into the backyard of a residence up in the South Hills," Kleitz says. "I have heard through FEMA that there have been some homes that have been adversely affected by flooding, with water in their basements."
There isn't even a proper irrigation ditch to funnel the water, which winds through the fence line and, sometimes, into homes.
Resident Jim Chaffin found out he was in a floodplain when he tried to build a shed in his back yard, he was furious when he found out that city infrastructure was causing the flood plain.
"I'm calling it a sewer," Chaffin said. "It's a two-foot conduit, culvert pipe, running horizontal and sticking right out of the side of the hill. It terminates right at the property line of these people who are in the city and it uses their backyard as a settling pond. The guy that lives there, he says it runs full... now that's a lot of water running out of a 24-inch diameter pipe."
Quite a lot of water indeed, one resident says he experienced four and a half feet deep water in his basement. Kleitz says he was made aware of the problem last fall after a resident in the county questioned the flood plain designation, since then he says he has notified the City of Missoula, but hasn't heard of any plan to fix the situation. In the meantime, the EPA has been called to investigate.