Is Lehi at risk for runoff flood?

PROVO — Three cities are developing on the benches near Point of the Mountain without proper consideration of drainage and are putting Lehi homes at risk of being flooded, according to the North Utah County Water Conservancy District.

Members of the district's board of directors asked Tuesday for help from the Utah County Commission in dealing with drainage concerns created by developments in Highland and Alpine in Utah County, as well as those in Draper that have crossed over the ridge.

The water district contends that those cities are relying too much on drainage areas designed to alleviate flooding and high runoff, particularly the Dry Creek basin.

"What we're finding more and more is, as development is taking place in both the Draper area and the Alpine and Highland area, that basin is being used by developments as their detention or retention pond," said Frank Mills, a member of the water district's board of directors.

As more houses are built, more water flows into Dry Creek and then down into a retention basin designed to handle historical runoff, said Mills, who also is Pleasant Grove city administrator.

"We're finding water in there 12 months out of the year," he said. "That basin is designed to have water come into it and flow out, not to have water back up behind it."

And that could cause problems when the basin is needed to handle heavy spring mountain runoff, Mills said. Add to that the silting coming from the developments above Dry Creek and north Utah County could see a repeat of 1983, he said.

"(In spring 1983), we had a heavy rain on frozen ground and there was massive flooding in the north end (of Utah County) coming off those dry farms," Mills said. "We're in that situation right now."

Development taking place on the benches — pavement, curbs, gutters, sidewalks and rooftops — is serving as frozen ground, he said.

"If we have in the early spring the water backed up like we did this year and then have a storm event like that, Lehi city and the unincorporated area below Lehi city down to (Utah Lake), they're going to be under water," Mills said.

The North Utah County Water Conservancy District has sent letters to Highland, Alpine and Draper city officials to make them aware of the potential problems. The district is requesting meetings with city officials to discuss possible solutions, said Van Burgess, chairman of the district's board of directors.