RAWLINS (AP) - A study has recommended replacing a Rawlins reservoir that leaks about 200,000 gallons of water a day.

WWC Engineering, which looked at the city's projected water needs during the next 50 years, recommended replacing the leaky Atlantic Rim reservoir and building a new, 644-acre-foot reservoir next to the Water and Wastewater Treatment Plant south of Rawlins.

Stan Miller, project manager for WWC, said the reservoir is being weakened by the leak although the extent of the damage isn't clear.

"What we're sitting on is a bit of a time bomb," Miller said. "It could be a short-term or a long-term time bomb."

The Laramie-based firm estimated that the cost of building a new reservoir is about $11.1 million.

With a 67 percent grant from the Wyoming Water Development Commission, that could mean a fee increase of $4.90 per month per water tap. Decommissioning the Atlantic Rim Reservoir could mean even higher water tap fees.

The Atlantic Rim reservoir, which was built in the late 1970s, has another shortcoming: No pipeline is in place to allow it to store water from the North Platte River.

The overall goal of the water study, which was funded by a grant from the Water Development Commission, is to ensure adequate water supplies to Rawlins during drought and peak use periods, such as late summer.

"There's going to be times in the next 50 years when you're present system is going to be stressed," Miller said.

Leakage from the Atlantic Rim Reservoir feeds the nearby Rim Lakes.

An alternative to a new reservoir is to pump water from the North Platte River, where the city of Rawlins has water rights.

WWC calculated that the average cost of doing this would increase fees $6.88 per month per water tap, but the cost would vary greatly depending on energy costs and the severity of drought.

"It costs a lot of money to pump," Miller said. "It sucks electricity like you don't believe."

Information from: Rawlins Daily Times