TITLE:
Application of a Groundwater Classification System and GIS Mapping System for the Lower Ruby Valley Watershed, Southwest Montana
AUTHORS:
Scott M. Payne, Ian A. Magruder, William W. Woessner
KEYWORDS:
Aquifers; Hydrogeology; Watershed; Groundwater Management; Geographical Information Systems; Rivers/Streams; Surface Water/Groundwater Connection; Land Use
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.5 No.8,
August
14,
2013
ABSTRACT: Classification of groundwater conditions at the watershed scale
synthesizes landscape hydrology, provides a mapped summary of groundwater
resources, and supports water management decisions. The application of a
recently developed watershed-scale groundwater classification methodology is
applied and evaluated in the 100,000 hectare lower Ruby
Valley watershed of southwestern Montana. The geologic
setting, groundwater flow direction, aquifer productivity, water quality,
anthropogenic impact to water levels, depth to groundwater, and the degree of
connection between groundwater and surface water are key components of the
classification scheme. This work describes the hydrogeology of the lower Ruby Valley watershed and illustrates how the classification system is applied to assemble,
analyze, and summarize groundwater data. The classification process provides
information in summary tables and maps of seamless digital overlays prepared
using geographical information system (GIS) software. Groundwater conditions in
the watershed are classified as low production bedrock aquifers in the
mountainous uplands that recharge the moderate productivity basin-fill
sediments. Groundwater levels approach the surface near the Ruby River
resulting in sufficient groundwater discharge to maintain stream flow during
dry, late summer conditions. The resulting classification data sets provide
watershed managers with a standardized organizational tool that represents
groundwater conditions at the watershed scale.