What do you do with a worn-out dam?
That is a question Sandy, state and irrigation company officials are contemplating as the reservoir behind the 77-year-old dam in Bells Canyon stands empty.The dam leaks, and the reservoir was drained in June for safety reasons. The dam sits on the Wasatch Fault and can't be repaired to meet current safety standards, and its owners do not want to pay $93,000 to tear it down.
And even if it could be safely rebuilt, the cost would far outweigh its value as an irrigation reservoir.
Even the name is a mix-up: Owned by the Bell Canyon Irrigation Co., the dam sits in what is known as both Bell and Bells Canyon.
Sandy owns just more than one-third of the stock in the irrigation company and uses its water for culinary purposes. Even though the city can take its water from an inlet in Dry Creek above the dam, Sandy is planning to raise money for Bell Canyon work and to buy additional stock to gain 50-percent-plus ownership of the irrigation company. The latter would be done in part by selling 350 shares in another water company.
Rather than bulldoze the entire dam, Sandy Public Works Director Darrel Scow is pursuing a plan to modify the dam structure so the portion of the dam below the leak-causing sinkholes can still be used to keep some water, about one-fourth of the dam's total capacity, in the reservoir. The result would be an aesthetically pleasing body of water that could be used to lend some aid to irrigators and to have a facility that can be used as a flood detention pond, Scow said.
Salt Lake County flood-control engineers have said they never incorporated the dam in flood-control plans and that it isn't needed as a flood-control fixture. But Scow said oldtimers in the area recall seeing the empty reservoir go from empty to full in 24 hours a number of times - and once in just six hours.
"The reservoir has, in essence, served a detention function for each period of high runoff since construction in 1914," consultant Bruce N. Kaliser wrote in a letter asking county engineers to consider the dam's flood-control benefits.
The city and county are in the initial stages of those discussions, Scow said.
Any proposal to use the dam would have to be approved by the state engineer's office, which hasn't officially condemned the dam but is making sure the reservoir stays empty until any plan to use the old dam passes muster.
"They've been real cooperative," said engineer Richard Hall with the Utah Dam Safety Office. "At this point in time, I think the (irrigation) company is convinced they can't keep the dam in the long run. The state engineer's position is: if they have a proposal to have some kind of minimal pond for recreation, or possibly use a portion of the reservoir for flood control, then we might entertain that. Otherwise, we want it breached."
Whatever happens, Scow believes a decision is needed before the snow melts next spring.