Background and Purpose

Population in the Flathead Valley has increased by more than 25 percent in the last decade to about 70,000, all of whom, with the exception of Whitefish, rely on groundwater, primarily from the deep aquifer. The deep confined aquifer in the Flathead Valley is a thick deposit of gravel and sand, the top of which lies 75 to over 400 feet below the land surface. This deep aquifer is the most utilized aquifer in the valley, supplying high-capacity municipal and irrigation wells in addition to thousands of domestic wells. Continued growth and localized water-level declines in the deep aquifer have raised concern about potential impacts from withdrawals.

Project Scope

This investigation examines the characteristics of the confining unit, the hydrologic relationship among surface water, shallow aquifers, and the deep confined aquifer, water-level trends, and recharge to the deep aquifer.  The study is implemented through the following tasks:

Setting spring site well

• Collect data from private wells and springs, existing monitoring wells, and wells installed specific to this project
• Evaluate groundwater-level trends and changes over time
• Use gravity, barometric, and drill-hole data to examine the characteristics and areal extent of the confining unit
• Map the transmissivity of the aquifer
• Investigate possible locations and mechanisms of recharge and discharge to the deep aquifer based on water budgets, isotopes, and flow paths
• Develop a groundwater budget

---

Project Duration: May 2010 to June 2013

GWIP Personnel Assigned:

James Rose, Hydrogeologist
406.496.4848
jrose@mtech.edu

John Wheaton, Senior Hydrogeologist
406.272-1603
jwheaton@mtech.edu

Project Factsheet (PDF file)

Recent Presentations:

• Deep Aquifer Hydrogeology, The Flathead (Kalispell) Valley — AWRA October 14, 2016, John Wheaton, James Rose, Ali Gebril, Liddi Merridith, Andy Bobst
• Science on Tap —Three-Dimensional Geologic Model of the Flathead River Valley at Kalispell, Montana, — April 5–6, 2016, James Rose
• Science on Tap — Hydrogeology of the Deep Confined Aquifer — April 5–6, 2016, John Wheaton, James Rose, Ali Gebril, Elizabeth Meridith, & Andy Bobst
• Three-Dimensional Geologic Model of the Flathead River Valley at Kalispell, Montana, Kalispell, Montana — April 5–6, 2016, John Wheaton & James Rose
• Deep Aquifer Hydrogeology, The Flathead (Kalispell) Valley, Kalispell, Montana > — April 5–6, 2016, John Wheaton & James Rose
• The Deep Aquifer & Subsurface Geology of the Flathead Valley Presentation (poster), Kalispell, Montana — April 5–6, 2016, John Wheaton & James Rose
• Flathead Valley Deep Aquifer: Geologic Setting and Hydrogeologic Implications 2015
• Flathead poster Oct 2011 (PDF file)

Publications and Reports: (none yet available)

Project data available here:
http://mbmggwic.mtech.edu/sqlserver/v11/menus/menuProject.asp?mygroup=GWIP&myroot=BWIPKL&ord=1&

In the News:
Hungry Horse News, March 2, 2011