Measuring the Waters of the Blackfeet Reservation: A USGS–Blackfeet Partnership

The Blackfeet Nation wants a deeper scientific understanding of the water on the Blackfeet Indian Reservation in northwestern Montana. It needs that knowledge as it puts the Blackfeet Water Rights Compact into effect, starts new water-use projects and improves the Blackfeet Irrigation Project.

Since 2019, the U.S. Geological Survey (USGS) and the Blackfeet Water Department (BWD) have been building a hydrologic data program together, in phases: measuring the flow of streams and canals, installing and running streamgages, monitoring groundwater levels, and managing the data. The results describe today's conditions and will be the baseline against which the Nation's water projects are measured.

USGS streamgages on the Blackfeet Indian Reservation. Image from the USGS fact sheet on the Blackfeet hydrologic assessment

Phase 1 — 2019

• Gathered existing hydrologic data and chose where to start collecting more.
• Installed two streamgages on September 19, 2019:

• Both report data online every 15 minutes, and a project web page carries the description and the data.

The two streamgages installed in 2019. Images from the USGS fact sheet on the Blackfeet hydrologic assessment

Phase 2 — 2020

• Kept the first two gages running and scouted sites for more.
• Installed a third gage at Birch Creek at Bullhead Bridge, near Valier (06098120), on August 25, 2020.
• Assessed sites for a groundwater monitoring network.

Installing the Birch Creek at Bullhead Bridge streamgage, August 25, 2020. Image from the USGS fact sheet on the Blackfeet hydrologic assessment

Phase 3 — 2021 onward

• Installed a fourth gage, Birch Creek below Heart Butte Road, near Heart Butte (06094900).
• Set up the Blackfeet Hydrologic Assessment Technical Working Group in spring 2022, moderated by the BWD, to discuss the project's design and progress.
• Completed synoptic discharge measurements across the Birch Creek drainage in 2022, to see where the main stem gains and loses water — from tributaries and from irrigation withdrawals. The work included field demonstrations for BWD staff and Blackfeet Tribe members.
• The Montana Bureau of Mines and Geology installed groundwater wells in 2022 with funding from the USGS National Ground-Water Monitoring Network, to be maintained by USGS as part of the Blackfeet project and its Climate Response Network.

The Birch Creek below Heart Butte Road streamgage, September 14, 2021. Image from the USGS fact sheet on the Blackfeet hydrologic assessment

The data

Everything is public through the USGS National Water Information System: river stage, discharge and water temperature, at 15-minute and daily steps.

Streamflow at Two Medicine River above Badger Creek, September 18, 2019, to October 6, 2021. Image from the USGS fact sheet on the Blackfeet hydrologic assessment

What comes next

The working group will recommend new surface-water and groundwater monitoring sites, building toward a reservation-wide network that gives a quantitative picture of its water. Possible work includes:

• more synoptic streamflow measurements on selected streams and canals, under different conditions;
• choosing sites for new streamgages;
• reviewing existing reports, geologic maps and drillers' logs for future groundwater and water-quality studies.

A further goal is to build Blackfeet capacity to collect, evaluate and manage hydrologic data: USGS will offer training to BWD staff, Blackfeet Community College faculty and students, and others in the Tribal community.

Gerald Lunak, Director of the Blackfeet Water Department, who said in 2019 that the partnership strengthens the Tribe's ability to manage the Blackfeet Nation's waters. Image from the USGS fact sheet on the Blackfeet hydrologic assessment

Sources

Based on U.S. Geological Survey and Blackfeet Water Department Hydrologic Assessment of the Blackfeet Indian Reservation, Montana, by Sean Lawlor, Rodney Caldwell, Timothy Bartos and Brett Price, U.S. Geological Survey Fact Sheet 2023–3012; a work of the United States government in the public domain. The source spells the creek both "Cutbank" and "Cut Bank," and says both "two groundwater wells" and "this well"; the number of wells is left out.