Water Availability in Bozeman
Bozeman is located within the Upper Missouri River Basin: a closed basin. This means that there are no new surface water rights available and water supply is limited.
—Montana DNRC pg. 45; City of Bozeman Utilities; Nora Shelly, Bozeman Daily Chronicle
Bozeman’s water comes from two sources
80% from snowmelt in the Gallatin Range that feeds Bozeman Creek and Hyalite Creek
20% from a developed spring at the headwaters of Lyman Creek in the Bridger Range
Bozeman’s water supply is finite and particularly vulnerable to climate patterns
Warmer temperatures mean earlier snowmelt in the spring, which means less water available for the drier and hotter summers.
Bozeman’s demand will exceed its water supply
Considering Bozeman’s rapid growth and climate variability, various models predict Bozeman to run out of enough water to support its population between 2027 and 2040. The graph at right predicts between 2027 and 2032 depending on snowpack and drought. The Gallatin Watershed Council predicts that date to be 2036.
This graph shows the years in which projected water demand would meet and exceed supply, assuming a population increase of 4 percent annually and no additional water conservation actions. The value of 9,011 AF reflects a worst-case scenario reliable water supply value, whereas the value of 11,042 AF reflects a 1-in-50-year drought taking place annually. However, Bozeman has adopted conservation measures in 2024, which this graph does not include.
Bozeman currently has around 16,517 AF (acre feet) of reliable water supply or 11,920 AF (if there is a 1 in 50 year drought each year), and we are currently using 49% (or 68%) of our total water supply (8,054 AF): 7,100 in use plus 944 committed for development. The City expects water use to increase 35% in the next ten years, but expects to have enough water supply to meet demand.
—Bozeman Development Code Transportation and Environment meeting on 2/24/2025
Slide from February 24, 2025 BDC Transportation and Environment Meeting.
The City of Bozeman has implemented various water conservation measures in the 2023 Water Conservation and Efficiency Plan, which have helped increase the water supply, such as mandatory water efficiency offsets, efficient irrigation, or leak repair assistance.
The 2013 Integrated Water Resources Plan calls for 50% of Bozeman’s future water supply to come from conservation, according to Mayor Cunningham’s March 18, 2024 State of the City Speech at 23:19.