A team of researchers at the Montana Bureau of Mines and Geology is studying how development on Billings' far West End could impact future groundwater availability, to give city and county officials a sense of the need for future city services so that they can make informed development decisions.
Fortunately, the aquifer — which supplies groundwater to the 1,794 wells in the area — is not “crashing,” meaning being rapidly depleted, according to Elizabeth Meredith, a hydrogeologist on the study.
Billings Public Works initiated the project by applying for a grant from the state’s Ground Water Steering Committee in 2021, beating out eight other projects for the funding.
Which goes to show that the issue is not unique to Billings. The DNRC formed a Comprehensive Water Review working group, to work on developing policy reforms for groundwater use in anticipation of next year’s legislative session. The Billings aquifer is one of five being studied by the group.
People are also reading…
Across the state and beyond, water scarcity, a tale as old as the West, is colliding with the relatively more recent phenomenon of increased demand for housing and development. As agricultural lands are converted to subdivisions, aquifers lose recharge from irrigation and add discharge, from consumptive use.
“At what point does the balancing act no longer hold?” Meredith said, of the purpose of the study.
The capacity of the Billings aquifer was last studied in 2002, which identified that two-thirds of the recharge came from irrigation ditch loss and one-third came from precipitation.
The team at MBMG wrapped up their main field work, of measuring water levels in wells, last year. They’re now building a computer model to “explore future what-if scenarios” around how differing amounts of land use change and development will impact the aquifer in the future. They expect to complete their report by early 2025.
Future solutions could include expanding city services, which presents “affordability challenges,” according to the DNRC’s Comprehensive Water Review working group. For one, the cost of hooking up to a public water system is passed from the developer to homeowners. Plus, increased demand required municipalities to pay for capacity-expanding improvements. The new Billings West End Water Treatment Plant, for example, will cost $68 million, making it the most expensive public works project in the city’s history.
Extensions of city services into the county could take 10 or more years to provide, according to Boris Krizek, an environmental engineer with Billings Public Works.
The DNRC’s Comprehensive Water Review working group is studying ways to fund and incentivize the expansion of municipal water systems.
Scientists are also considering “managed aquifer recharge,” which would mean leaving fields open and replenishing groundwater using surface water. This has not been done in the state, but it was identified as a potential strategy in last year’s Drought Management Plan.
Developing MAR “will require a comprehensive understanding of ground and surface water interactions, as well as water rights implications,” according to the plan.
“It’s a big topic of conversation right now,” Meredith said.
Meanwhile, the DNRC’s Comprehensive Water Review working group is exploring changing existing rules around the construction of wells exempt from the permitting process, or those that use less than 10 acre-feet of water per year.
The stated goal of the group is to protect water resources and existing water rights, as well as to develop “new, holistic policy solutions” to address new and existing needs for water, in the face of increased demand and decreased supply.
Of the 1,794 wells in Billings, 1,767 are exempt and 27 are permitted. Exempt wells are said to be “de minimis,” meaning of little importance.
“Cumulative effects of de minimis is not actually de minimis,” according to the working group.