Poster Session I
Project Type
Poster
Faculty Mentor’s Full Name
Kelsey Jencso
Faculty Mentor’s Department
Forest Management
Additional Mentor
Payton Gardner, payton.gardner@mso.umt.edu, Geosciences
Abstract / Artist's Statement
Lower Grant Creek (LGC) flooding during the 1997 water year prompted the installation of groundwater and surface water monitoring sites to identify the factors leading to residential basement flooding. The Missoula Water Quality District is seeking an updated analysis as rapid land-use change and development is expected in the coming years. I compiled and analyzed groundwater elevation data from 2020-2025 to investigate whether relationships with rainfall and snowmelt are evident in the LGC alluvial aquifer and to characterize whether different locations in the groundwater system gain or lose water from the up-valley surface water system. I compared groundwater elevations and static water levels from monitoring wells (MMW4, MMW8, MMW12, WQD3, and WQD44) located in the LGC to high elevation SNOTEL snowmelt, precipitation, and Grant Creek stream discharge and stage height. Linear regression and Pearson’s correlation analyses indicated that snowmelt and Grant Creek streamflow and stage height drive changes in groundwater elevations across the wells in the area. My analysis supports Grant Creek's role as a losing stream to the aquifer and as a dominant control on groundwater dynamics, especially during peak runoff from snowmelt. Variability in response time highlights the influence of geology and distance on hydraulic connectivity in the area. Wells MMW8 and WQD3 show signs of recharging more quickly (3-4 days) to the increased stage height of Grant Creek and snowmelt. This project underscores the need to reassess groundwater elevation throughout the realignment and development process. Comparing recharge variables with groundwater response across varying water years provides early warning to the timing of potential flooding for developers and agencies.
Category
Physical Sciences
An Assessment of Recent Meteoric Variables on the Lower Grant Creek Alluvial Aquifer System
UC South Ballroom
Lower Grant Creek (LGC) flooding during the 1997 water year prompted the installation of groundwater and surface water monitoring sites to identify the factors leading to residential basement flooding. The Missoula Water Quality District is seeking an updated analysis as rapid land-use change and development is expected in the coming years. I compiled and analyzed groundwater elevation data from 2020-2025 to investigate whether relationships with rainfall and snowmelt are evident in the LGC alluvial aquifer and to characterize whether different locations in the groundwater system gain or lose water from the up-valley surface water system. I compared groundwater elevations and static water levels from monitoring wells (MMW4, MMW8, MMW12, WQD3, and WQD44) located in the LGC to high elevation SNOTEL snowmelt, precipitation, and Grant Creek stream discharge and stage height. Linear regression and Pearson’s correlation analyses indicated that snowmelt and Grant Creek streamflow and stage height drive changes in groundwater elevations across the wells in the area. My analysis supports Grant Creek's role as a losing stream to the aquifer and as a dominant control on groundwater dynamics, especially during peak runoff from snowmelt. Variability in response time highlights the influence of geology and distance on hydraulic connectivity in the area. Wells MMW8 and WQD3 show signs of recharging more quickly (3-4 days) to the increased stage height of Grant Creek and snowmelt. This project underscores the need to reassess groundwater elevation throughout the realignment and development process. Comparing recharge variables with groundwater response across varying water years provides early warning to the timing of potential flooding for developers and agencies.