Final Environmental Impact Statement

Vestal Final Environmental Impact Statement Chapter 3
Streamflow Regime
Streamflows throughout the Black Hills have been reduced over the last century. This
has been a result of fire suppression. There has been an increase of woody biomass.
Higher leaf areas from increased woody biomass will increase evapotranspiration and
interception, resulting in lower streamflows and the drying of springs (USDA Forest
Service 2003b).
Peak flows data has been collected for a limited time on several streams in an around the
Vestal project area. The streams include; French Creek, three (3) sites, two (2), six (6)
and 19 years; Laughing Water Creek, six (6) years; and Ruby Creek, six (6) years. Peak
flows on these creeks occurred from March to October with the most occurring in June
(USGS 2011).
Stream Health
Perennial and intermittent streams within the project area were reviewed to determine
Stream Health Rating (SHR). Stream health is defined as “ The condition of a stream
versus reference conditions for the stream type and geology, using metrics such as
channel geometry, large woody debris, substrate, bank stability, flow regime, water
chemistry and aquatic biota” (USDA Forest Service 2006b), is an indicator of water
quality. It is a good way to give an overview of a stream and a means to compare them to
each other. Many streams have the majority of their length on private lands. Those
perennial and intermittent streams with very minor amounts on National Forest lands
were not assigned a SHR. The remaining streams were assigned SHR as discussed
below:
French Creek – Is a major tributary to the Cheyenne River. The entire length is
86.2 miles. Sixteen percent (16%), or 13.7 miles, of this stream is in the Vestal
project area. Of that portion, 76% is on private land and 24% is on National
Forest. There are two distinct reaches, above Stockade Lake and below Stockade
Lake. The reach above Stockade has many impacts with a significant amount of
stream crossings, significant grazing on private land, and channelization in the
City of Custer, to highlight some impacts. The reach below Stockade Lake had
significantly less impacts with a few road/stream crossings that could be
improved. Most crossings are on county roads. The SHR for French Creek above
Stockade Lake would be diminished and French Creek below Stockade Lake
would be At-Risk.
Glen Erin Creek – Approximately 98% (4.5 miles), is within the Vestal project
area. Only 0.1 miles is outside the project area. Forty percent (40%) is on private
land. There are two distinct reaches on National Forest. One reach has had CCC
activity on it, building dams and building restoration structures in the stream.
Two of the dams are no longer functioning and one is holding water and creating
a nice pond. The restoration work has created wonderful wetlands along the
stretch that was restored. The SHR for this reach would be At-Risk. The other
reach, or lower reach, has been acquired recently and the stream has not been
grazed for a number of years. This reach has a SHR of Robust.
Ruby Creek – The entire length of this stream, 6.7 miles, is within the Vestal
project area, however 69% of this stream is located on private land. Two (2)
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