Murphy Spring Creek is a
cold groundwater and basin-fed stream, entering the North Fork of the Blackfoot River at
stream mile 9.9. The stream originates on the north side of Ovando Mountain and flows
6 miles south to its junction with the North Fork and has a base flow of 4 cfs. The
upper four miles of Murphy Spring Creek is in public ownership, with the lower two miles
being in private ownership.
In order to prioritize
restoration resources, we developed a fisheries-based restoration priority scorecard,
based on biological, social and financial considerations, for 83 impaired tributaries of
the Blackfoot River. Murphy Spring Creek is ranked 17 of 83 streams surveyed. Fishery
surveys indicate the stream to be a North Fork westslope cutthroat trout spawning stream
and a bull trout rearing stream.
Culvert after restoration.
significant fishery impacts have been identified in this stream. One is a perched and
undersized culvert near the mouth (stream mile 0.5) of Spring Creek. A 1997 sampling
documented juvenile bull trout below the culvert but none above it. In 1999, the property
changed hands allowing us to remove and replace the elevated and perched cuvert with a
larger culvert with baffles. In 2001, we re-sampled fish populations above the new
culvert. The survey found the culvert was passing juvenile bull trout including
young-of-the-year, as well as all size classes of westslope cutthroat trout.
The second fishery
problem was a defunct irrigation structure (stream mile 1.6) that served a large
irrigation reservoir. This diversion created several problems including impacting
upstream migrations of fluvial westslope cutthroat trout, entrainment of downstream
migrating fish and dewatering of the stream for 1.6 miles.
In 1998, the irrigation
diversion was replaced with a new structure that has a collapsible brace that will allow
for debris and bedload movement down the stream. The structure was also fitted with a
Denil fish ladder that will allow for upstream migrations as well as minimum instream
flows. A self cleaning fish screen and water lease is being negotiated with the water
users to assure instream flows and that all species and size classes of fish are
eliminated from the ditch. The new landowner on the lower two miles of Murphy Spring
Creek entered into a conservation easement with the Montana Land Reliance perpetually
protecting the entire watershed.