The Big Springs gold mining operation is located in northern Nevada within
the Humboldt National Forest, on land administered by the U.S. Forest Service.
Independence Mining Company operated the Big Springs Mine from 1987 through the
mid-1990s. The mining operations extended along the upper reaches of the North
Fork of the Humboldt River. This stream provides important habitat for the
Lahontan cut-throat trout, a species listed as threatened by the U.S. Fish and
Wildlife Service. Healthy riparian areas are considered to be an important
component in improving trout habitat.
The first major riparian enhancement activity during mining operations
involved relocating several miles of the county road away from the river. This
road would be used for ore haulage. The use of smaller haulage equipment allowed
a narrower road to be constructed, which substantially reduced the amount of
disturbance. Design elements significantly reduced erosion and sedimentation,
while providing a buffer for the wildlife habitat in the riparian areas. Sumps
and silt fences were constructed along the relocated road to reduce water flow
velocities and capture sediment. In the mine areas, a variety of sediment and
erosion control structures were constructed, and sediment ponds were built below
waste rock dumps.
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Structural improvements of the river channel were undertaken to stabilize
severely eroded stream banks and improve trout habitat by the installation of
rock armaments and placement of drop-log structures. A long section of the river
that had been diverted into an irrigation ditch was re-routed into its former
channel.
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Sediment pond between waste rock dump and riparian
corridor.
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Regeneration of riparian vegetation after 7 years of rest from livestock grazing.
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The company agreed to build 5 miles of fence to exclude livestock grazing in
the drainage area for 10 years. Willow stem and aspen root cuttings were planted
along with containerized or bare-root seedlings to stabilize the river banks,
create shade, provide nesting structures for birds, and protection for other
wildlife.
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The environmental benefits of Independence Mining Company's reclamation
efforts have been exceptional. Data collected during monitoring showed that:
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the condition along the river banks, in the vicinity of the mine, had
improved 33% in three years;
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aquatic organisms indicative of above-average water quality have
persisted since monitoring began in 1987; and,
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fishery surveys have shown that after a population decline in 1991,
numbers more than doubled during the next two years.
Through careful planning, design, and personal commitment, the Big Springs
project has become a hardrock mining showcase, and was featured in a U.S. Forest
Service video series.
