Cold Water Refugia and Bank Stabilization Project

Seven High Ranch WHIPPED into Shape by Pam Harrington, Trout Unlimited – Many of the streams in the Owyhees have flash spring torrents that leave unwanted results for land owners. A common story is too much water followed by no water in a short period of time. A factor that can exacerbate this regime is lack of floodplain to let water soak into the ground. Water without operating floodplain leaves properties too quickly, resulting in drier conditions for longer periods and dried up streams aren’t good for anybody.

Bank stabilization project at Seven High Ranch, Reynolds Creek - before.

Bank stabilization project at Seven High Ranch, Reynolds Creek – before.

Floodplains create a magical exchange between surface water and ground water – scientists call it the hyporheic exchange. The floodplain soil acts as a sponge to hold the water when there is a lot. When surface water flows lessen, the ground water that has been charged by flooding spring conditions finds its way back to the stream during the hot dry months.

Fortunately, Jerry Hoagland’s ranch on Reynolds Creek contains a population of redband trout. The Wildlife Habitat Incentive Program (WHIP) that was available through the NRCS allowed to address his stream’s challenges. The WHIP program is no longer offered under the new Farm Bill, but wildlife habitat projects are still available through the E’sIP program. Trout Unlimited’s Pam Harrington asked to partner to improve stream conditions for both the rancher and trout. The application was drafted and Pam modified a 404 permit that was already in the works to make it also fit the wildlife habitat goal.

Small pools were identified that remained after the stream was nearly bone dry. These pools were filled with redband trout, awaiting the fall rain to come. Local knowledge of Reynolds Creek was key to pinpointing where projects could do the most good. These isolated pools are the key to redband’s survival during a drought.

Scientists have wondered how cold water redband trout can survive in the desert. Some speculated these trout could withstand warmer water than other rainbow trout. The main answer turned out to be the ability of trout to find cold water pools. The reason the pools had cold water was that they were fed from groundwater upwelling. Hyporheic Exchange at work!

Bank stabilization project at Seven High Ranch, Reynolds Creek - after.

Bank stabilization project at Seven High Ranch, Reynolds Creek – after.

What did we do in Phase I? The project used a resource created from another project to protect sage grouse. Junipers were cut down nearby. These trees were used to stabilize the bank. Juniper revetments allow the bank to heal by taking pressure off the bank. Large poles of cottonwood trees were driven into the soil down to the water table. These poles will turn into trees and shade the creek and hold the soil in place. Willow cuttings were also placed behind the revetment and these cuttings will turn into a mass of vegetation that holds the bank from eroding away. The revetment also leaves a place for trout to hide and bugs to hang on and create food. The step pool environment that Reynolds creek affords was also enhanced using small rock barbs to create deeper pools where water was already noted to be the last remaining live water in the drought last year.

The project addressed two things that redband trout need most in the Owyhees: SHADE and WATER.

In Phase II of the project, completed in November of 2014, step pools were installed to mitigate a head cut that was forming. This provided pools for redband trout to utilize. Thousands of willow cuttings were installed to reduce erosive banks and to slow down flows during the high spring flows, allowing water to seep into the groud to be released again as surface water as flows subside.

One more phase of restoration work is slated for Seven High Ranch in the future.

Trout Unlimited is starting an Owyhee Home Waters Redband Trout Program. If you have redband trout on your property and would like to consider a project to improve habitat and your operation, contact Pam Harrington, pharrington@tu.org or 345-9800.

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