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The future of water: Bozeman officials working on water supply challenges

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It’s no secret to anyone in Bozeman: There isn’t a lot of water to go around.

Water has long been limited in the valley, due to the semi-arid climate and closed basin status. Add to this equation climate change impacts yielding reduced snowpack and hotter temperatures and mounting population pressure.

Despite a 2021 summer of scorching heat and minimal precipitation across Montana that prompted a drought declaration in Bozeman, the city predicts it has reliable capacity for now.

But impacts on water supply from population growth and climate change loom large.

“We recognize the effects of climate change in terms of extreme drought, in terms of thinner snowpack and extreme storms that can overwhelm the system and wildfire that can interrupt water delivery,” Deputy Mayor Terry Cunningham said. “We recognize that this past year, rather than being considered an aberration, might be considered the new normal moving forward or at least not an unusual event.”

Cunningham and other city officials stressed that tackling the issue of water supply is not a new endeavor for the city. In 2013, a master plan for water management stated there would be a gap between water demand and supply within the next 50 years and listed a number of measures that could be taken.

But city officials said now is the time to take bolder steps.

The city is exploring whether it can get additional water from underground or out of the region. It is also developing a tool to pin down how much water is reliably available to the city each month. And city commissioners plan to consider more stringent landscaping codes and watering restrictions.

“We need to get serious about water,” Commissioner Jennifer Madgic said. “We can’t keep living like we have an endless supply.”

Hyalite Reservoir, City Water Plan, Wild

The water in Hyalite Reservoir has receded, exposing much of the surrounding bank on Thursday, Dec. 2, 2021. Hyalite is one of the main sources of water for Bozeman.

A tricky puzzle

The city’s water supply comes from three sources: Lyman Spring in the Bridger foothills, Sourdough Creek and Hyalite Reservoir south of town.

Montana uses a system of prior appropriation to determine water rights, so those whose rights are older get priority when water supply is low. Bozeman is in the Upper Missouri River Basin, which is a closed basin, meaning there are no more water rights to be acquired.

“There’s plenty of water here reliably to meet the immediate growing needs of the city,” City Engineer Brian Heaston said. “But as we continue to grow that steadily chips away at that reliable available volume.”

Heaston said demand will outpace the reliable yield of the city’s existing water supply in 2033, assuming a consistent 4% growth rate brings the city’s population to 88,000 at that time.

However, Heaston said the city bases the reliable yield of supply on a 1-in-50-year drought scenario, similar to the conditions seen this year. The idea is to plan for the worst case scenario.

The city can try to acquire existing water rights, but Heaston said it doesn’t happen often.

Instead, to expand supply, the city is planning to establish groundwater wells as an additional water source.

Heaston said the city has identified a spot near the Bozeman Sports Park on Flanders Mill Road as a site to drill test wells this spring to test the aquifer and gather the data necessary to apply for a well permit with the state.

Bozeman Sports Park, City Water

Stacks of hay bales sit off of Baxter Lane, near the Bozeman Sports Park on Thursday, Dec. 2, 2021. The city has identified a spot near the Sports Park to drill a test well this spring.

He said the well would provide resiliency to the existing water supply and could function as a backup if something compromised the Sourdough Water Treatment Plant or if a wildfire endangered the city’s water supply.

Bozeman’s capital improvement plan, which lays out how the city will spend its budget for infrastructure projects and other budget items, includes an allocation of $10 million for the project in 2025, though it is far from a sure-fire deal.

Because Bozeman is in a closed basin, a municipal well project would also have to include a strategy to deal with how pumping the groundwater will impact surface water.

“Groundwater and surface water are just different expressions of the same source, so water that’s in the ground is going to express itself in a creek or a river somewhere else,” Heaston said. “Because all of the water rights in the surface waterbodies in the upper Missouri Basin have all been appropriated, the development of a groundwater resource is going to deprive or deplete the amount of water that is flowing in surface water bodies.”

Kerri Strasheim, the regional manager for the Department of Natural Resources and Conservation, said a mid-2000s court case connected surface and groundwater more closely in the law, requiring any large groundwater developments to show they won’t adversely affect anyone.

In order for a permit to be approved, the city would have to prove it could make up for its impact, possibly through acquiring the proper transferred water rights in order to offset the amount of water that the well would deplete.

“That’s a tricky puzzle to put together,” Heaston said.

The city first has to figure out where the groundwater the well would deplete shows up as surface water, which requires complicated modeling and studying.

“It is a challenge finding the location to where they can pull groundwater, the amount that they need, and then (finding) a nearby location to mitigate the groundwater impacts on the surface water,” Strasheim said. “It has to be close enough to affect essentially the same surface water sources of the wells themselves will impact.”

Hyalite Reservoir, City Water Plan, Wild

The sun reflects off the ripples in the water at Hyalite Reservoir on Thursday, Dec. 2, 2021. Hyalite is one of the main sources of water for Bozeman.

‘A finite resource’

Bozeman isn’t the only entity after more water.

The city only represents about 45% of the population in Gallatin County, and the valley is still home to significant agricultural use. Agricultural users have some of the oldest water rights in the basin.

Walt Sales, a state legislator who farms near Manhattan, is a member of the Association of Gallatin Agricultural Irrigators. He said some agricultural water users are also looking to increase their water supply, but noted that the city has to keep communication with farmers open.

“Any time you’ve got a finite resource, you’re going to have conflict,” Sales said. “I think if we can have that understanding of what it is we’re trying to do and what it is we want to protect, and how do we do that, we can move forward.”

Cunningham, the deputy mayor, echoed Sales, saying the city can’t act like it’s an isolated user of water.

“We have to think of not only what the uses are as a city, but what the entire valley’s needs are, what role we play in that and how we can collaboratively work to ensure that water needs are being met, not just Bozeman’s most senior water right,” Cunningham said.

It’s more than just farmers — the city is also working together with other local governments on water planning.

Bozeman, Belgrade and Gallatin County signed onto an agreement earlier this year committing them to a regional study on additional water and wastewater infrastructure.

Heaston said one thing the study will look into is whether it’s feasible from a legal and infrastructure perspective to tap into Canyon Ferry Reservoir as an additional water source for the region.

“We recognize that the growth and development is not going to stop anytime soon,” Heaston said. “We need to be prepared for the supply needs well into the future and come up with a list of options that are going to get us there.”

Conservation measures

While the city is pursuing expanding its supply, conserving the water it has now is an important way to make sure there’s enough water in the future.

The city’s integrated water resources plan found much of the gap between supply and demand that’s expected to surface in the next few decades can be made up through conservation.

Bozeman already offers incentive and rebate programs for people to replace their lawns with more water-tolerant landscaping, or to install water-efficient appliances in their homes, but commissioners are looking to take it a step further.

Several commissioners said that mandating the stage two drought restrictions that were in place this summer every year going forward is on the table.

Under those restrictions, residents were allowed to water their lawns only two days of the week and were restricted from doing any outdoor watering between 10 a.m. and 6 p.m.

During the stage two drought, which the city implemented in July and lifted in October, water use dropped by over 20%.

City Manager Jeff Mihelich said during a normal summer, 50% of the city’s potable water is used for lawn irrigation.

“That’s just too much … we can do more work with our residents and property owners about water conservation and how they use water,” Mihelich said. “This summer was actually a blessing in disguise.”

The city commission is also scheduled to take a look at implementing more drought-tolerant landscaping codes for new subdivisions during a meeting early next year. Jessica Ahlstrom, city water conservation program manager, said suggestions include requiring more efficient irrigation systems and lawns with less turf grass.

The city is also looking at water use for its own outdoor spaces. Ahlstrom said the city is auditing its irrigation systems and has plans to make them more efficient.

Ahlstrom is also drafting a conservation plan slated to include about 25 measures aimed at water conservation.

“That really will tell us how much water we can expect to save over the next 20 years,” Ahlstrom said.

While the city’s approach to conservation is multi-faceted, Ahlstrom and other officials said a behavioral change among residents will be necessary.

“We want people to recognize that the decisions they make everyday about their water use has an impact on the community,” Cunningham said, noting the high rate of water use for lawn irrigation. “Everyone has to look in the mirror and say, does that make sense? Am I being a responsible member of the community if I’m overwatering non-native grass?”

Informed planning

Some might think there is a simpler solution to the water dilemma: stopping growth.

Though putting a moratorium on new development has been pursued by a handful of mountain west towns, the idea seems unlikely to take hold in Bozeman.

“There are unintended consequences of growth (and) development being made difficult within the city limits of Bozeman,” Madgic, the commissioner, said. “‘I’m fearful of us promoting sprawl, whether it’s development out in Gallatin County, or adjacent counties.”

Development outside of city boundaries can also have adverse impacts on water quality.

Torie Haraldson, a water quality specialist with the Gallatin Local Water Quality District, said a municipal well serving homes within city limits is preferable to the same homes, outside of city limits, with individual wells and septics on each lot.

A municipal well would get monitored for water quality more frequently, Haraldson said, making it safer.

“I know there’s people out there that would like to just say there’s not enough water, let’s just tell people they can’t move here or that growth can’t happen,” Haraldson said. “I think since that’s probably not a realistic idea, the city working to provide (water) within municipal infrastructure is really overall protective of water quality, more so than letting all those people that would move here anywhere put in all their individual wells and septic systems.”

According to Heaston, growth doesn’t always mean more water use.

Even though population more than doubled between 1980 and 2020, overall water use by the city was actually slightly lower last year than it was 40 years ago. The per capita daily water use in 1980 was 291 gallons. It was 114 gallons in 2020.

But the fact that water is a firm upper limit on how many people the city can sustain is part of the reason the city is developing a tool that will determine the reliable quantity of water available to the city from its existing sources.

Called the water optimization and management tool, Heaston said it will take into account scenarios for population growth, climate change impacts and conservation efforts.

It will also compare reliable monthly supply with monthly demands, Heaston said, and will be factored into land use and development decisions.

“We absolutely can’t be in a position where we’re approving development, and we don’t have the water supply to support it,” Heaston said. “One of the main reasons that the tool is coming together is to make sure that we’re making solid land use and development decisions that are sustainable given the amount of water that we reliably have available to us currently.”

In the meantime, several commissioners emphasize that the list of options to solve the problem is long.

“The commission, the city staff is well aware of this issue. We have been working on it for decades,” Cunningham said. “It doesn’t mean that it’s getting any simpler. But we have our eye on the horizon.”

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Nora Shelly can be reached at or 406-582-2607.

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