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| Gold Creek |
Missoula County, Montana |
Primary Project Type: Instream Restoration
Secondary Type: |
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This photograph depicts Gold Creek prior to restoration in 1996. Since the earl... |
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Primary Problem: Loss of Fish Habitat
Secondary Problem: |
| Main Restoration Action(s): Habitat enhancement |
| Native Fish Focus: Bull trout, Westslope cutthroat |
Is this project part of a watershed scale restoration? Yes
Click here for the description. |
| Project Dates: fall 1996 to 2002 |
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Initial Monitoring: 1990 to 1996
Restoration Implementation: fall 1996
Follow-up Monitoring: 1996 to 2002 |
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Lead Agency:
Montana Fish, Wildlife and Parks
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| Project Partners: |
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| Project Location:
Gold Creek, a third-order stream, is the largest tributary to the lower Blackfoot River. It drains 98.6 square kilometers, enters the Blackfoot at river kilometer 21.7 and is 29 kilometers in length. Discharge at the mouth of Gold Creek was .06 cubic meters per second (2 cubic feet per second) in August 2000. The project area was located in the lower 4.8 kilometers of the stream, where most of the channel was stable, well-armored, and confined. An adjacent 4.6-kilometer control reach was located upstream of the project area and was largely unaffected by anthropogenic disturbances.
Click here for project area map.
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| Project Description:
Since the early 1900s, the riparian zone of Gold Creek was logged extensively and the stream was cleared of large woody debris. When large woody debris was removed from the channel, it was cut into 3-meter lengths and flushed out of the system during high spring flows. The cumulative effects of these impacts significantly reduced habitat complexity within and surrounding the stream. A 1996 habitat survey of the lower 4.8 kilometers of Gold Creek indicated aquatic habitat diversity was lost from old-growth timber harvest in the riparian area, and pools made up only 1 percent of the wetted surface area of this section of stream. There were 0.13 pools per 100 meters, and the section contained 0.42 pieces of wood more than 15 centimeters in diameter per 100 meters. Only two log-formed plunge pools were observed in the lower 4.8 kilometers prior to treatment. Low densities of age 1+ fish resulted from this habitat simplification. A control stream reach located upstream of the impacted area contained pools over 14 percent of the reach. In 1996, restoration activities were implemented and included the placement of 66 instream habitat structures made of native rock and wood. These were constructed to improve habitat quality in the lower 4.8 kilometers of stream channel. Gold Creek has consistently tested positive for whirling disease in recent years, but at very low infection levels. Whirling disease was not detected in Gold Creek in 2003. |
| Project Goals: The objectives of this project were to: 1) restore pool habitat and morphological complexity; 2) restore thermal refugia for Blackfoot River native fish including westslope cutthroat trout and bull trout. |
| Project Methods:
Land use in the Gold Creek drainage predominantly consisted of commercial timber harvest. Logging in the riparian area and removal of large instream wood from the channel greatly reduced the diversity of fish habitat. Prior to the restoration project, fish habitat consisted mostly of shallow, cobble-dominated riffles. Instream structures were installed in Gold Creek during the fall of 1996 to improve fish habitat. The channel was restored to a step-pool and riffle/pool sequence consistent with Rosgen B3, B4, and C3 channel types.
Click here for more detailed information on methods used.
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To create complex fish habitat, 66 rock and log instream habitat structures were... |
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This photograph depicts the riffle/pool sequence established on Gold Creek after... |
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| Monitoring Data and Collection
Methods: All habitat structures were surveyed during the fall of 1996 following project completion and resurveyed during the fall of 1997 at a similar discharge (approximately 1.0 meter per second). Surveys included measurements of pool length (tail crest to head), average width, and maximum depth. Dominant substrate, pool type, formation, and hydraulic function (e.g., log-formed plunge, lateral scour) were noted. All measurements were accompanied by detailed photo-documentation. In addition, electrofishing was used to collect information on population estimates, relative abundances, and standing crop estimates of bull trout, westslope cutthroat trout, rainbow trout, brown trout, and brook trout, from before restoration in 1996 to after restoration in 2003.
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| Was this project effective
and how was this determined? The use of natural materials, as well as thoughtful restoration designs that incorporated the observed channel types and fluvial processes, contributed to a successful project without augmentation from synthetic materials such as concrete, wire rope, or chain-link fencing. In addition, the winter of 1996-97 accumulated snow packs in the Blackfoot River drainage of approximately 180 percent of the 30-year norm. During the following spring, run-off from snowmelt produced an estimated 50-year flood in the drainage (approximately 33 meters per second). This flood event was of moderately high magnitude and provided a unique opportunity to evaluate the success of the project.
Click here for more detailed evaluation of project success including photos and tables.
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(Before) Gold Creek before restoration. Showing simplified channel composed of ... |
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(After) Gold Creek following restoration. Showing a plunge pool created by a lo... |
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| Confounding Effects/Additional
Information: Although significantly more structures failed in the C channel than in the B channel, failure rates may have been affected by the character of each channel type rather than the structures themselves. B channel types are confined by valley walls and have little floodplain development, whereas C channel types meander and have a more extensive floodplain. The sinuosity inherent in C channel types contributed to the failure of all pool types except lateral scour pools, which rely on channel migration for their development. Rock-formed pools had the lowest success rate in this channel type. The complex shape of sills created by rocks may have reduced the velocity of the water intended to scour. The frictional resistance of the substrate may have led to pools filling in and subsequent failure. |
| Project
Specs (all specs are estimates): |
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Man Hours:
240 (includes surveys/staking, design, construction, monitoring and agency/landowner time)
Cost of Materials:
$21,500 (Trees donated by Plum Creek and DNRC: $40,000 value)
Subcontracted Costs:
$30,552
Overall Estimated Cost:
$54,652
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| For more information on this project
contact: |
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Ron Pierce, Montana Fish, Wildlife, and Parks, Email: bigfish@blackfoot.net
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| This information
was collected by: Clint Sestrich and Michelle White |
| Project last updated on: 5/22/2007 |
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