Background and Purpose
The purpose of this project is to investigate the cause of dewatering in the lower reach of Lolo Creek. Possible causes include residential development in the town of Lolo, water use by irrigators (within or beyond allocated water rights), Lolo Creek responding to a lowered alluvial water level in the Bitterroot River valley, climate or some other factor.
Local residents and landowners have noted that during some years the stream has become intermittent in the lower reaches becoming disconnected with lower flow to river. Although there is anecdotal evidence that this has happened since the 1960’s, frequency appears to have increased. This has been documented in the 1980’s and again in 2007, 2011, 2013 and 2015.
Lolo Creek provides Bull Trout habitat and has historically been a productive fishery and water resource for the entire perennial reach from above Lolo Hot Spring all the way to the Bitterroot River. Groundwater and surface water use included ditch diversions and subsequent irrigation, groundwater withdrawal through increasing number of private wells and public water supply discharges to meet development.
GWIP Personnel Assigned:
Mike Chambers, Graduate student, Montana Tech
Project Factsheet (pdf)
Project Reports: (none yet available)
Project data available here: