Rebman Creek Rock Riffle Construction

Objectives

The objectives of this project are to reestablish pool riffle morphology within the system. Minimal existing pool habitat was determined to be a detriment to low flow refuge and to rearing capabilities of the system. Reestablishment of a higher percentage of pool area is the primary objective.

FRBC Region/ MELP Region/ MoF Region

Cariboo/Cariboo/Cariboo

Author

Michael Parker

Proponent

Weldwood of Canada Ltd., Quesnel Division

Watershed

Rebman Creek

Location

Rebman Creek is a tributary to the Willow River. Located in the Quesnel Forest District, it lies approximately 100km Northeast of the City of Quesnel.

Introduction

Rebman Creek is approximately 3m bankfull in width with a gradient ranging 3-6%. It is a rearing area and high water refuge for fish from the mainstem Willow River. An extremely high (>53%) proportion of the watershed has been logged, with much of it leaving little to no riparian area. Pool habitat was approximately 3% over the first 4 reaches. LWD was extremely limited. Extreme low flows in August often cause the first reach to go dry, and lack of pools in the upper reaches cause a variety of problems from thermal warming, predation, crowding, etc. during low flow periods.

Assessments and Prescriptions

As part to the Willow River Watershed, Rebman has been subject to Overview and Level 1 Fish Habitat and Riparian Assessments completed in early 1998 by LGL Ltd. Level 2 Assessments were conducted during the fall of 1998. Many upslope assessments have also been completed and road deactivation and slope stabilization projects were underway during the fall of 1998.

Rehabilitation Work

Given the late start of in stream works in Rebman, six consecutive sites in Reach 4 were prescribed for works during the fall of 1998. The remaining 40+ will be completed in 1999. This years work consisted of the construction of rock riffles using local materials and a hand crew from Randall and Associates. This crew pioneered a technique of using compressed air to loosen impacted substrates, freeing the rocks necessary to construct the riffle and pool sequence. This technique appeared to be successful in execution, and will therefore likely be used in the coming year to eliminate riparian damage that would be caused by using a machine. This was deemed important as regeneration of riparian was providing the primary cover along the mainstem. Fish salvage was conducted prior to construction of individual structures.

Cost Summary

Restoration Results

Six structures were completed over a test section of approximately 200 meters of stream. Reevaluation of these hand constucted structures that utilized on site materials will be done in the spring, and a determination made if it is necessary to use machinery and / or imported materials to complete remaining structures.

Proposed Work

Approximately 40 remaining riffle structures and bank stabilization efforts are to be completed during the 1999 season.

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Hand constructed rock riffle completed on Rebman Creek mainstem, Willow River watershed.