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| Trapper Creek |
Klamath County, Oregon |
Primary Project Type: Instream Restoration
Secondary Type: Instream Restoration |
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Gabions were built in the 1960s along both sides of Trapper Creek adjacent to th... |
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Primary Problem: Channel Alteration
Secondary Problem: Loss of Fish Habitat |
| Main Restoration Action(s): Channel reconstruction, Habitat enhancement |
| Native Fish Focus: Bull trout |
Is this project part of a watershed scale restoration? No
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| Project Dates: 1998 to 2003 |
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Initial Monitoring: 1996 to 2002
Restoration Implementation: June 2002 to September 2003
Follow-up Monitoring: October 2003 - ongoing |
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Lead Agency:
U.S. Forest Service - Deschutes National Forest, Crescent Ranger District
Upper Deschutes Watershed Council
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| Project Location:
Trapper Creek is located approximately 70 miles south of Bend and 20 miles west of Crescent, and is the main creek flowing into Odell Lake.
Click here for a map of the project area.
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Project Description:
Odell Lake supports the only known population of federally listed Threatened bull trout in the upper Deschutes River watershed. Within the Odell Lake watershed, Trapper Creek provides the only bull trout spawning habitat. The Odell Lake bull trout population is a significant resource for the upper Deschutes watershed because it is a small, isolated population that was separated from the lower Deschutes basin by lava flows approximately 5,500 years ago. This population is recognized as the only remaining non-reservoir, adfluvial bull trout population in the state of Oregon. (Adfluvial refers to fish that live as adults in a lake and spawn in a creek.)
Over the past 70 years, channelization, berm creation, and the installation of gabion baskets have severely degraded spawning and rearing habitat for bull trout and significantly diminished the hydrologic integrity of Trapper Creek, threatening the persistence of the Odell Lake bull trout population. High stream velocities caused by these modifications have created an unstable system that is reducing ‘egg to emergence’ success and the survival rates of juvenile bull trout that rely on stream habitat for cover and protection from high flow events. The accelerated flows displace spawning gravel and can flush eggs from redds, with the ultimate impact being the potential loss of a year’s age class. Successive years of gravel flushing can result in the loss of several years of age classes, leading to a severely depressed population. Pre- project habitat measurements found less than 4% of the habitat available to bull trout is rated as ‘fair to good’ for bull trout spawning and rearing (Dachtler 1999).
The Trapper Creek Restoration Project was conceived after site monitoring showed that the 100yr flood event of February 1996 caused severe hydrologic instability, damaging habitat to the federally threatened bull trout. The USFS was charged by the USFWS to develop a long-term solution to lessen the impacts of flooding to bull trout habitat.
Dachtler, N. S. 1999. Trapper Creek bull trout spawning and fry rearing habitat assessment. Deschutes National Forest, Bend, Oregon. |
Project Goals: The goal of this project is to create and enhance bull trout spawning and rearing habitat by restoring the biologic and hydrologic function to the Trapper Creek channel and floodplain.
Specific goals include: (1) Increase hydrologic stability of Trapper Creek - increase floodplain, connectivity, reduce bank erosion / bank shear stress, reduce width / depth ratios, redirect thalweg off of road bridge wing wall, establish riparian vegetation and stream cover; (2) Increase bull trout spawning and rearing habitat - accumulate and retain spawning sized gravels, increase pool quality and pool complexity, create quality off-channel habitat for bull trout rearing; (3) Improve public awareness of watershed issues through interpretive opportunities; (4) Maintain established recreational uses at Trapper Creek Campground and protect the restored areas from recreational impacts. |
| Project Methods:
Restoration was accomplished by creating a meandering channel including critical habitat elements for bull trout, such as off-channel habitat for juvenile refuge, and in-channel features including pools, riffles, large woody debris, boulders, gravel beds, and other features. Heavy equipment was used to increase stability and hydrologic function of the stream channel by increasing meander bends, narrowing the channel, decreasing the streambed gradient, sloping back vertical banks, installing energy dissipation pools, and removing earthen berms and gabions to allow flood flows to access the flood plain.
Click here for more details on methods used.
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(After) The bankfull channel was narrowed and the unstable vertical banks were l... |
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(After) Structures, such as this rock cross vane, increased pool, rearing, and s... |
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| Monitoring Data and Collection
Methods: Monitoring on Trapper Creek has been conducted by the ODFW and/or the USFS since 1996. Both reaches were monitored post-restoration and monitoring is scheduled to continue for the next 5 to 10 years to monitor success both physical and biological.
Click here for more details on monitoring.
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Was this project effective
and how was this determined? Fish populations are reflected in the quality of their habitat, especially cover and velocity (Lewis 1966). The effects of straightening severely limits salmonid habitat, and habitat enhancement techniques that move the channel towards a more natural range will allow expansion of the population White (1973). Trapper Creek was designed with this in mind. Reference reaches of a natural condition and of similar channel type were used to determine the design characteristics of the restored Trapper Creek channel. Post-restoration monitoring results showed channel improvements created an additional 880 m2 of good-to-fair spawning habitat — a four-fold increase from pre project conditions. An additional 836 m2 of good-to-fair fry rearing habitat was also created by this project — a 3.6-fold increase from pre-project conditions. Observations of juvenile bull trout increased from 26 in 1996 to 180 in 2005, and bull trout use was greatest in the lower portion of the project area where wood volumes were the highest. Post-restoration bull trout redd surveys show use of the restored channel for spawning.
In 2004 and 2005, the years following restoration completion, Trapper Creek experienced less than bankfull discharge due to below average precipitation in the drainage. Consequently, Trapper Creek had not yet experienced a discharge that would adjust the physical dimensions of the rehabilitated channel. However, the less than bankfull seasons presumably allowed settling and strengthening of the log and boulder structures and establishment of riparian vegetation to increase bank stability. Photopoint monitoring has shown good reestablishment of riparian vegetation.
Click here for more details.
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(Before) Below the railroad bridge fast water habitat dominated the stream.... |
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(After) The restoration of step pools as energy dissipaters increased pool, rear... |
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| Confounding Effects/Additional
Information: |
| Project
Specs (all specs are estimates): |
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Man Hours:
Machine Hours: 216 hrs
Cost of Materials:
126 tons of spawning gravel: $824, 314 tons of boulders: $5560, Fill material: $1500, Wood hauling: $280, Barrier material: $230, 3600 plants, 45 kg of seed: $19,297
Overall Estimated Cost:
$231,700 (NEPA: $50,000, Pre-project Design and Monitoring: $42,000, Implementation: $97,930, Riparian Rehabilitation and Protection: $41,770)
Cost per foot: Phase 1: $103, Phase 2: $82, Total: $115
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| For more information on this project
contact: |
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Louis Wasniewski, USFS Forest Hydrologist, Deschutes National Forest, Email: lwasniewski@fs.fed.us
Ryan Houston, UDWC Executive Director, Upper Deschutes Watershed Council, Email: rhouston@deschuteswatersheds.org
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| This information
was collected by: Molly Boucher |
| Project last updated on: 4/7/2007 |
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