Missoula County commissioners on Thursday awarded a contract with HDR to assess future water needs in the Lolo area under population projections through 2070.

Deb Bell of public works said the contract will determine the population served and estimate projected growth. It will then establish water demand based for the next 50 years.

“It's all part of our ongoing water rights through the Water Court,” said Bell. “As part of our continuing land planning effort, it will tie in with the next phase of the mapping firm we're going with as well.”

Greg Robertson, the county's director of public works, said the county has already been through Water Court and the case was adjudicated. The Montana Attorney General and other parties were also involved.

“The Water Court has ordered this study to validate the need for the claimed water right in terms of volume,” Robertson said. “It's fairly new, but it's based on case law.”

Robertson added that other Bitterroot Valley communities, including Hamilton, Stevensville and Victor, will follow a similar process.

“It's not unique to Lolo,” he said. “It just establishes an engineering basis for the claim we have asserted.”

Robertson said Lolo is served by a shallow aquifer and several county pumps. The community has seen steady growth in recent years. Long-term water use can be based on current use, he said.

“We have historical volume metric use, and calculations for population expansion as well, and they can calculate that out,” he said. “It's pretty loosey goosey, but it's what forms the basis for the judge's decision and what was agreed to by the Attorney General's office as well.”

The contract with HDR is for $8,900.