NORNS CREEK 2000 FISH HABITAT ENHANCEMENT

Transcription

1 COLUMBIA BASIN FISH & WILDLIFE COMPENSATION PROGRAM NORNS CREEK 2000 FISH HABITAT ENHANCEMENT PREPARED BY Michael Zimmer FOR Columbia Basin Fish & Wildlife Compensation Program Ministry of Environment, Lands & Parks BC Fisheries November 2000 IN PARTNERSHIP WITH Castlegar & District Wildlife Association Columbia Kootenay Fisheries Renewal Partnership

2 NORNS CREEK 2000 FISH HABITAT ENHANCEMENT Prepared for: Columbia Basin Fish and Wildlife Compensation Program Victoria Street Nelson, B.C. V1L 4K3 Prepared by: Michael Zimmer, R.P.Bio. Zimmer & Associates Environmental Consultants Box 2115 Grand Forks, B.C. V0H 1H (Ph/Fax) November 30, 2000

3 EXECUTIVE SUMMARY Planning and implementation phases for fish habitat enhancement work were completed for Norns Creek in A 65 m long eroding bank in reach 1 was re-visited to improve rip-rap and maintain bioengineering treatments. Approximately 21 m 3 of graded riprap up to 900 mm diameter was used to improve bank protection along the toe of the bank. Modifications were also made to one of the rock spurs constructed in The fish habitat enhancement structures in reach 2 were re-visited to implement safety modifications and structure maintenance to increase habitat value for rainbow trout fry. Approximately 50 large boulders were strategically placed around most of the structures to deflect high flows. Structures were also trimmed to remove protruding elements which might be hazardous during high flows. Select structures were re-ballasted and re-anchored to improve stability. Several dozen thinned conifer trees were also integrated into most structures to increase available fry cover. The fish habitat goals of this project were: (a) to maintain and increase stability of various existing structures, (b) to create additional conditions for gravel deposition within a useable portion of the channel for use by spawning adults; (c) and to enhance rearing habitat for juvenile rainbow trout by providing small wood debris. A secondary, but important, aspect of this project was to improve public safety in relation to the existing fish habitat enhancement structures. Funding and support for the project was provided by the Columbia Basin Fish and Wildlife Compensation Program, Castlegar & District Wildlife Association, Columbia Kootenay Fisheries Renewal Partnership, Columbia Power Corporation, Peter Kiewit Sons Ltd., and the Regional District of Central Kootenay. Zimmer & Associates Environmental Consultants ii

4 ACKNOWLEDGEMENTS This project was completed through the combined efforts of the Columbia Basin Fish & Wildlife Compensation Program (CBFWCP), the Castlegar and District Wildlife Association (CDWA), Fisheries Renewal British Columbia (FsRBC), Columbia Power Corporation (CPC), and Peter Kiewit Sons Ltd.. Steve Arndt from the CBFWCP provided direction and planning input. CDWA provided personnel for maintenance work; volunteers included: Fred Salekin, Gerry Brown, Henry Kuryluk, Jim Salekin, Barry Salekin, and Gary Gebert. Clint Tarala assisted with field work through a grant from BC Hydro Youth 2000 to Selkirk College. Fisheries Renewal British Columbia (FsRBC) assisted with funding through the Columbia-Kootenay Fisheries Renewal Partnership (Bill Green), which also provided the necessary tools. Wally Penner of The Columbia Power Corporation and Peter Kiewit Sons Ltd. provided the necessary rock, including transportation, to the project site. Hans Kolman, the adjacent land owner in reach 1, provided access to the project site through his property and agreed to keep livestock from the rehabilitated bank area. The Regional District of Central Kootenay provided access to reach 2. Zimmer & Associates Environmental Consultants iii

5 TABLE OF CONTENTS EXECUTIVE SUMMARY... ii ACKNOWLEDGEMENTS... iii TABLE OF CONTENTS...iv TABLE OF FIGURES...iv 1.0 INTRODUCTION METHODS RESULTS SUMMARY AND RECOMMENDATIONS REFERENCES...6 TABLE OF FIGURES Figure 1. Lower portion of Norns Creek indicating 2000 fish habitat enhancement treatment areas....4 APPENDICIES APPENDIX A APPENDIX B PHOTOS HYDRAULIC ANALYSES Zimmer & Associates Environmental Consultants iv

6 1.0 INTRODUCTION A fish habitat enhancement project was undertaken by the Columbia Basin Fish and Wildlife Compensation Program (CBFWCP) in reaches 1 and 2 of Norns Creek through July and August 2000 as part of a multi-year enhancement project (Zimmer 2000; McCleary 1999a; McCleary 1999b). Work completed during 1998 and 1999 was revisited in 2000 for a variety of improvements and maintenance. The CBFWCP retained Zimmer & Associates Environmental Consultants to plan and supervise the majority of the fieldwork for the different components. Field work was completed with the assistance of Mills Brothers Contracting and volunteer support from the Castlegar and District Wildlife Association (CDWA). The fish habitat goals of this project were: (a) to ensure stability of existing structures, (b) to create additional conditions for gravel deposition within a useable portion of the channel for use by spawning adults; (c) and to enhance rearing habitat for juvenile rainbow trout by providing small wood debris. A secondary, but important aspect of this project was to improve public safety (i.e., swimmers, boaters, tubers, etc. (Photo 4)) in relation to the existing fish habitat enhancement structures. Zimmer & Associates Environmental Consultants 1

7 2.0 METHODS Instream work for 2000 consisted of additional riprap placement in reach 1, safety and maintenance modifications to structures in reach 2, and increasing margin rearing habitat by integrating thinned trees into structures in reach 2. Bank stabilization work in reach 1 was improved by adding approximately 21 m 3 of riprap. Hydraulic analysis for determining riprap grading and placement was prepared by Kerr Wood Leidal Associates (KWL 1999; Appendix B). The toe of the slope was shored up using the riprap. Placement extended approximately 2 m into the creek channel. Riprap was placed on the streambed and pushed into the substrate to secure the placement. Riprap placement was undertaken on July 29 and 30, Spoil piles from work undertaken at this site in fall 1999 were removed to an upslope location and the area leveled. Work completed in reach 2 focused on improving the level of safety of the structures to water users. Numerous large boulders were used to block off the upstream surface of previously identified, potentially problematic structures. Rows of three or four boulders were placed at such locations to plug openings through each structure and to force higher flows overtop of a treated structure. Projecting wood debris portions of potentially problematic structures were removed with a chainsaw. Sawed off portions will minimize the risk of hanging up if there are any water users during the high water period. Three other structures were addressed to increase the amount of ballast. Additional boulders were placed at appropriate anchor points adjacent to wood debris structural elements for each structure to be repaired. Half-inch diameter braided steel cable was used to tie down structural elements to anchor boulders using the Hilti epoxy system. A wood auger and a Hilti rock drill were used to make cable connections in the wood and boulders. The majority of structures in reach 2 were also treated with small wood material (thinned trees) of <0.15 m diameter and 2 m long to further block gaps in the structures and also to increase the available rainbow trout fry habitat (Culp et al. 1996). Approximately 200 thinned trees were used to increase fry cover on the majority of structures in reach 2. Zimmer & Associates Environmental Consultants 2

8 3.0 RESULTS The 65 m bank treated in 1999 in reach 1 was revisited to increase stability of the toe. Approximately 21 m 3 (3 loads) of angular rock similar to that used in 1999, was added to the toe of the riprap bank. The toe was further extended approximately 2 m into the creek channel (Photo 3). A third rock groyne was originally proposed for this location, but due to a lack of rock material only enhancement of the original two groynes was undertaken. Monitoring the rock groynes from the effects of the 2000 freshet indicated little or no movement of individual rock elements. This can largely be attributed to the expansive floodplain available to attenuate the flows from Norns Creek, and perhaps the relatively mild freshet. The spoil piles left behind from the 1999 work were removed to an upslope location on the adjacent Kolman property. The site was revisited in early September and seeded with a reclamation mix ground cover. The original bioengineering work was also revisited in April (Photo 1) and August. In August the live stakes showed signs of distress with wilted foliage and browning (Photo 2). It is likely that a large portion of the stakes, primarily those higher up on the banks may not have survived the hot dry summer period. The ground cover seed placed under the coco-matt looked to be successful. Several safety modifications were done on most of the structures in reach 2. Volunteers from the CDWA removed the protruding portions of the problematic structures. Structures were trimmed with a chainsaw so structural wood pieces were flush with the direction of flow. Several large boulders were also placed by excavator upstream of problematic structures to deflect flows around and over each structure at the various anticipated flow levels. The thinned tree component was completed in early August by the CDWA (Photos 10 and 11). Immediately after placement of the small wood material, rainbow trout fry were observed seeking cover in the newly available habitat. Observations were made during the instream work in reach 2 on the habitat use by rainbow trout fry. The majority of structures, particularly those immediately downstream of gravel areas (Photo 12), were heavily used by fry. In one instance approximate densities of 20 in m 3 (0.2 m X 0.2 m X 0.1 m) was observed (Photo 13). The site was also revisited twice in fall 2000 to observe habitat use by spawning kokanee. Numerous kokanee were observed throughout reach 2 coinciding with flow separation areas and gravel deposits immediately downstream of numerous individual structures (Photo 14). Of particular interest was the occurrence of kokanee spawning across the channel cross section including in mid-channel, apparently in suitable sized gravel (Photo 15). Zimmer & Associates Environmental Consultants 3

9 Figure 1. Lower portion of Norns Creek indicating 2000 fish habitat enhancement treatment areas. Zimmer & Associates Environmental Consultants 4

10 4.0 SUMMARY AND RECOMMENDATIONS Work completed in reach 1 of Norns Creek included: 1.A total of 21 m 3 of angular rock was placed to shore up the toe of the riprap bank 2.Spoil piles left from 1999 were relocated to an upslope location 3.Herbaceous mix of ground cover was added to the cleaned site 4.Survival of original ground cover was high 5.Survival of live stakes was marginal in late summer Work completed in reach 2 of Norns Creek included: 1.Removal of protruding portions of enhancement structures to improve safety 2.Addition of boulders to direct flows around and over structures 3.Addition of small wood debris to improve safety and increase fry habitat 4.Addition of ballast to three structures to improve performance 5.Relocation of some large wood debris The treated areas in reaches 1 and 2 should be routinely monitored to determine stability and effectiveness during and post freshet 2001 and during high bank water levels from the Columbia River for a minimum of 2 years. Monitoring should follow recognized methods (Gaboury and Feduk 1996) and focus on the following aspects: 1. determine rate of survival of seeding and live stakes 2. determine stability and rate of erosion of riprap treatment 3. determine stability and functioning of rock groynes and large wood structures 4. prepare a report identifying maintenance and supplementation requirements Further mortality of some of the live stakes is expected. True indications of planting success are typically observed in year two after planting, as the first year is most stressful. The site should be supplemented using recognized techniques (McCullah and Kendrick 1996) in Spring 2001 to replace unsuccessful stakes. The monitoring aspects will ensure proper functioning of the various treatments and determine if further modifications or supplementation is required. Use of the area by juvenile fishes should be assessed by electrofishing or snorkeling in the enhanced reaches during summer of 2001 and periodically as the structures age. Zimmer & Associates Environmental Consultants 5

11 5.0 REFERENCES Culp, M.J., G.J. Scrimgeour and G.D. Townsend Simulated Fine Wood Debris Accumulations in a Stream Increase Rainbow Trout Fry Abundance. Transactions of the American Fisheries Society 125: Gaboury, M.N. and M. D. Feduk Draft Watershed Restoration Program Fish Habitat Restoration Projects Monitoring Protocol. Kerr Wood Leidal Norns Creek Habitat Enhancements Flow, Velocity, and Riprap Sizing Estimates. Prepared for Columbia Basin Fish & Wildlife Compensation Program. 5 p. McCleary, R. 1999a Norns Creek Fish Habitat Enhancement Project. Prepared for Columbia basin Fish & Wildlife Compensation Program. 22 p. + Append. McCleary, R. 1999b. Application for Approval of Instream Works. Prepared for Columbia Basin Fish & Wildlife Compensation Program. McCullah, J. and A.L. Kendrick Biotechnical Erosion Control for Slopes and Streambanks. International Erosion Control Association. 96 p. + Appends. Zimmer, M Norns Creek Prepared for Columbia Basin Fish & Wildlife Compensation Program. 6 p. + Appends. Zimmer & Associates Environmental Consultants 6