Stream Restoration: “Build It and They Will Come”
By: Bryan Duggan
Water and Environmental Specialist
On Monday September 12, 2011 Kelly Robbins, Bryan Duggan and Mike Hargis, tribal
Land Resources and Environmental Services (LRES) staff put the finishing touches on a
long and promising restoration project in Fourth and Second Creeks on the Tribe’s
Empire Reservation.
Approximately 60 pieces of large wood debris and over 50 yards of gravel were added to
the creeks in the hope of providing habitat for fish and wildlife. Under the watchful eye
of Kelly Robbins the project manager, these structural pieces will provide the building
components surely needed within these streams on the Tribe’s Reservation.
Past environmental and biological surveys concluded that all streams on the Empire
Reservation were lacking in habitat complexity; as a result of decades of human related
impacts were lacking in habitat diversity. Repeated aquatic ecosystem studies show that
low habitat diversity, lack of habitat connectivity, and high sediment has contributed to
low species richness and diminished fishery population numbers.
It has long been the goal of the Tribe’s LRES department to restore the habitat within
these creeks to support cutthroat trout, pacific lamprey, and hopefully one day soon coho
salmon; who are more likely to utilize these small streams for spawning.
After months of planning which included drafting an environmental impact statement,
securing permits, and stockpiling large woody debris and rock, the project began early
this year with the removal of beaver and beaver dams from the system.
The idea was not to eradicate all beavers, but at least to control their numbers so habitat
connectivity could be restored and maintained. With minimum predator pressures on the
Reservation beavers, the populations, particularly in Fourth Creek were excessive enough
to create beaver pool after beaver pool throughout the Fourth Creek Basin. Although
beavers can create excellent juvenile salmon habitat, extensive pools have a distinct lack
of habitat diversity.
After the beavers were culled, tribal work crews breached the beaver dams to restore the
flow within the creek systems. Next work began on the placement of over 5,000 board
feet of large woody debris (LWD) within the creek channels. LWD adds structure to the
creek ecosystem, forcing the water to slow down, move around and dig underneath the
wood. These actions create different flow regimes in the water column, connect the creek
to the riparian zone and generate pools for fish to seek refuge.
Once the LWD were anchored in place tribal crews then piped in over 50 yards of
imported river rock gravel into both creeks. Although a messy and hard job, the gravel
will provide habitat not only for spawning fish but for the macro invertebrate community
as well. Macro invertebrates are the tiny animal organisms that make up a majority of the
aquatic food chain, a yummy meal for most fish species.
Prior to the placement of LWD and gravel, Kelly Robbins performed a presence and
absence survey for macro invertebrates for Fourth and second Creeks. What he found
were low diversity of species at low numbers of individuals. Kelly will again survey
these creeks after a number of years to see if these numbers change. That change will
help LRES determine the success of this project.
Until then we patiently await the winter rains; with the return of higher flows through
Second and Fourth Creeks, the streams will distribute and organize the new building
blocks according to it’s own forces; creating habitat that shall provide improved
conditions for the whole aquatic community.
Many thanks go out to Kelly Robbins, Mike Hargis, Jesse Davis and all those who
contributed time, resources, and assistance to this project.