Overview

In February of 1996, Trapper Creek experienced a 100 year flood event sparking concerns about the health of the creek and specifically, its spawning habitat for the federally listed “Threatened” bull trout. The bull trout live as adults in Odell Lake and spawn within the lower 0.7 miles of Trapper Creek. Known as the Odell Lake bull trout, this population is recognized as Oregon’s only remaining non-reservoir bull trout that live in a naturally occurring lake and spawn in a stream.

Further evaluations after the 1996 flood event demonstrated that 70 years of modifications were impacting the health of Trapper Creek and thus posing a danger to the persistence of the bull trout population. The U.S. Forest Service was charged with developing a long-term solution to improve the impacts of flooding to bull trout habitat. With funding and scientific support from the Upper Deschutes Watershed Council, the National Forest Foundation, the Oregon Watershed Enhancement Board, the Deschutes National Forest, the Oregon Department of Fish and Wildlife and the U.S. Fish and Wildlife Service, a major restoration effort was implemented in 2002 and 2003. Specific project objectives included:

1. Restore hydrologic function and bull trout habitat
2. Increase spawning and juvenile bull trout rearing habitat
3. Increase floodplain connectivity
4. Re-establish a stable meander pattern, width, depth and native bank material / riparian vegetation
5. Improve public awareness of watershed issues through interpretive opportunities
6. Maintain established recreational uses at Trapper Creek Campground and protect the restored areas from recreational impacts.

Restoration Results

The restoration efforts improved the average width of Trapper Creek from 50 to 32 feet and changed the average width to depth ratio from 35 to 16. Boulders and whole trees were utilized to create naturally occurring pools, fish habitat and bank stability. 200 feet of side channel was re-activated to restore critical rearing habitat.

Approximately 700 feet of gabion baskets (rock filled retaining walls) were removed and the sharp meander bends were enlarged to mimic naturally occurring stream systems and reconnect the flood plain. Log jam complexes and log and boulder structures were added back into the meander bend. These wood complexes provide necessary channel stability and critical fish holding and rearing habitat. The average width to depth ratio within the meander bend was reduced from 25 to 16 feet, narrowing the channel from 42 to 32 feet.

Fish Habitat Improvement

The channel improvements created an additional 880 m² of good to fair spawning habitat, providing a 4-fold increase from pre-project levels. An additional 836 m² of good to fair fry rearing habitat was also created by this project resulting in a 3.6-fold increase.

Habitat complexity in Trapper Creek was greatly increased with more pools, side channels, log complexes and increased floodplain width. This process has increased habitat by nearly five times as compared with what was available as recently as 1998. Based upon comparative studies in other streams, increasing habitat complexity will benefit the aquatic community within Trapper Creek.

Post project bull trout monitoring by ODFW during fall of 2003 found 12 of the 16 redds (bull trout spawning beds) within phase 1 of the project area. The remaining four were located within the wilderness area of the creek. 2004 surveys documented 12 redds in Trapper Creek, 10 of which were within the project area.

Riparian Restoration and Recreational Accomodations

Nearly 820 feet of cedar split rail fencing was installed to protect the stream and stream banks from campers and other recreationalists. Two campsites were permanently closed. Compacted areas such as trails and closed campsites were tilled and planted. Over 700 feet of Gabion baskets and 130 feet of berm were removed, and new streambanks developed, sloped and planted. About two acres of riparian habitat were planted using 3,600 native plants and 100 lbs of seed to rehabilitate the Trapper Creek project area.

Outreach