Or Creek Stream Bank StabilizationProject # 03.Co.02

Prepared by:

Bob Cavill, Ron Van Oord, John WorthenGreater Vancouver Regional District

Watershed Management Division

Prepared with the Financial Support of:

BC Hydro Bridge Coastal Fish and Wildlife RestorationProgram

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Executive Summary

Urbanization and sedimentation has resulted in the degradation of water qualityand fish habitat in the Coquitlam River/Or Creek drainage. Or Creek has beenthe site of a few small landslides in areas of glaciofluvial materials underlain byglaciolacustrine deposits. Subsequent erosion of this material has contributedsignificant amounts of fine textured sediments into the river system.

The Or Creek watershed is approximately 2100 hectares in size and is locatedapproximately 3 kilometres north of the City of Coquitlam. The flows to theCoquitlam River have been reduced due to the operation of the BC Hydro dam.The Watershed Management division of the Greater Vancouver Water District(GVWD) manages the Or Creek watershed via a 999-year lease from theprovincial government.

The intent of this project was to minimize sedimentation into Or Creek. The goalof the project was to protect and enhance fish habitat in the Coquitlam River/OrCreek system. In order to achieve this goal, the project had to satisfy waterquality and fish habitat objectives.

This project involved the construction of a 120 metre long rock armoured bermon the south bank to stop and contain slide debris from entering Or Creek.Another 120 lineal metres of rock armouring was placed on the north bank toprotect it from subsequent stream erosion. A total of 6 log jams were alsoinstalled in the stream channel. Some bioremediation was conducted on the slideitself.

The Watershed Management Division of the Greater Vancouver Regional District(GVRD) and the Habitat Enhancement Branch, Lower Fraser River Region ofFisheries and Oceans Canada (F&O) partnered to complete this bankstabilization project. This project was funded by the BC Hydro Bridge CoastalFish and Wildlife Restoration Program (BCRP).

This erosion control project was divided into 3 phases. This was done todifferentiate and prioritize the various activities. BCRP contributed funding in theamount of $97,225 and the GVRD provided $60,000 of in-kind contributions.

Based on the results of this project the following recommendations can be made:

1. The project management team should meet onsite annually to review anddiscuss the effectiveness of the project design.

2. A review of the effectiveness and appropriateness of the engineered logjams.

3. Any fine textured material that needs to be end hauled off site should bedone at the time of excavation.

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4. The development and growth of riparian plant species should bemonitored.

5. Effectiveness monitoring will determine the integrity and status of theinfrastructure that was installed in this area.

6. Subsequent remedial work should be conducted on a long termpartnership basis.

TABLE OF CONTENTS

EXECUTIVE SUMMARY............................................................................................................................. I

LIST OF FIGURES ...................................................................................................................................... 2

A. Bioremediation on the slide ........................................................................................................ 2B. Temporary access road into Or Creek ...................................................................................... 2C. Diversion trench ........................................................................................................................... 3D. Starting south side berm ............................................................................................................. 3E. Dumping rock for south side berm............................................................................................. 4F. South side berm during construction ......................................................................................... 4G. Removal of slide debris from the interceptor channel ............................................................ 5H. Phase 2 key way construction.................................................................................................... 5I. Phase 3 rock armour construction............................................................................................... 6J. Hauling woody debris for log jams ............................................................................................. 6K. Placing logs ................................................................................................................................... 7L. Log jam construction .................................................................................................................... 7M. Anchor placement for log jams .................................................................................................. 8N. Hydroseeding the berm ............................................................................................................... 8O. Slide before construction ............................................................................................................ 9P. Slide after construction ................................................................................................................ 9

LIST OF TABLES...................................................................................................................................... 10

INTRODUCTION......................................................................................................................................... 11GOALS AND OBJECTIVES........................................................................................................................ 11STUDY AREA ........................................................................................................................................... 11METHODS................................................................................................................................................. 12RESULTS.................................................................................................................................................. 15DISCUSSION............................................................................................................................................. 17RECOMMENDATIONS ............................................................................................................................... 18ACKNOWLEDGEMENTS............................................................................................................................ 19REFERENCES........................................................................................................................................... 20APPENDIX I – FINANCIAL STATEMENT ................................................................................................... 21APPENDIX II – PERFORMANCE MEASURES ............................................................................................ 22APPENDIX III – CONFIRMATION OF BCRP RECOGNITION ..................................................................... 23APPENDIX IV – AS-BUILT DRAWINGS .................................................................................................... 24

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List of Figures

A. Bioremediation on the slide

B. Temporary access road into Or Creek

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C. Diversion trench

D. Starting south side berm

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E. Dumping rock for south side berm

F. South side berm during construction

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G. Removal of slide debris from the interceptor channel

H. Phase 2 key way construction

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I. Phase 3 rock armour construction

J. Hauling woody debris for log jams

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K. Placing logs

L. Log jam construction

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M. Anchor placement for log jams

N. Hydroseeding the berm

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O. Slide before construction

P. Slide after construction

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List of Tables

Table 1. Fish Salvage Summary Results

Table 2. Summary of the Various Rock Products Installed During Phase 1

Table 3. Summary of the Rock Product Installed During Phase 2

Table 4. Summary of the Rock Product Installed During Phase 3

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Introduction

Over the years the Coquitlam River has been on the ‘top ten’ list of endangeredrivers in British Columbia. The area just upstream from the confluence of theCoquitlam River and Or Creek, a major tributary, has been the site of smalllandslides. The local glaciofluvial materials, underlain by glaciolacustrinedeposits, have been undercut leading to significant amounts of fine texturedsediments being deposited into the river system. Because the lower reaches ofOr Creek include good spawning habitat for coho and steelhead, thesedimentation has had a direct impact on fish habitat.

The intent of this project was to minimize further sedimentation into Or Creekfrom one of the larger and active landslides just upstream from the confluence ofthe Coquitlam River.

Goals and Objectives

The goal of this project was to ultimately protect and enhance fish habitat in theCoquitlam River/Or Creek drainage. Both water quality and lack of rearing siteand cover opportunities were concerns.

Short and long term water quality had to be protected from erosion during heavyrainfall events and high stream flows. Secondly, coho, steelhead and cutthroatrearing opportunities had to be created in the stream channel adjacent to theslide area.

Armouring the stream banks in the area of the active slide and constructing arock berm below the slide were key design features. Six logs jams were designedand installed in the stream channel near the slide to meet the rearing site andcover objectives.

Revegetation techniques were used with the objective of enhancing localterrestrial habitat. Bioremediation techniques added native plant species thatultimately increased biodiversity while also adding some slope stability.

Study Area

The Or Creek watershed is about 2100 hectares in size and is locatedapproximately 3 kilometres north of the City of Coquitlam. Or Creek is the maintributary to the Coquitlam River and provides the majority of flow to the riversystem. Annual precipitation is about 4000 mm per year. GVRD’s WatershedManagement Division manages the Or Creek watershed through a 999-yearLease with the Province. Or Creek Drainage is a water reserve and is currentlynot used for domestic water supply purposes.

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The Coquitlam River flows 10 kilometres from the BC Hydro Dam to the FraserRiver and supports anadromous and native fish populations. However, reducedwater flows, urban development and the operation of gravel pits on the CoquitlamRiver have degraded this habitat. The waters of Or Creek are consideredpotentially critical to the survival of salmonids in the Coquitlam River system. Themainstem of Or Creek is approximately 7 kilometres long and ranges from 100 to800 meters in elevation. Or Creek provides spawning and rearing habitat for bothsteelhead and coho. Riley et al. (1997) noted in a habitat survey an almostcomplete absence of large instream woody debris in the Coquitlam mainstem.Complex fish habitat associated with this type of structure was rarely present.Results of Riley's et. al. (1997) habitat survey suggested that lack of cover andhigh proportion of fine substrate at some mainstem sites might be limitingsalmonid production on the Coquitlam River.

GVRD Involvement

GVRD completed sediment source surveys and watershed assessments, relyingon Forest Renewal BC funding in 1997 and 1998. As a result of theseassessments, to minimize erosion in 1999, GVRD completed a bioengineeringtreatment of the active slump 1.1km upstream of the Coquitlam River junction.These works have been effective in reducing fine sediment delivery from thisslide into Or Creek and the Coquitlam River.

It was determined that slumps from the lower slide area (site of this project) willcontinue to be the largest single contributor of the approximately 2000 tonnes offine sediment that enters the Coquitlam River from the Or Creek watershedannually. Remedial works proposed were designed to improve the stability of thelower slide and reduce overall fine sediment supply to Or Creek and theCoquitlam River.

Methods

The project team consisted of Greater Vancouver Regional District (GVRD) andFisheries and Oceans (F&O) staff. The design was coordinated by F&O. Theproject management, survey and drafting services were provided by the GVRD.Site supervision and fieldwork was undertaken by GVRD staff and theenvironmental monitoring was conducted by F&O staff.

Several meetings were held to communicate responsibilities and ensure dutieswere completed on time. The project team decided that the original designshould be reviewed by a hydrologist and a geotechnical engineer. This was doneto ensure that the hydrologic and slope stability aspects of the design wereappropriate. Northwest Hydraulic Consultants (nhc) reviewed the hydrology withthe 200-year flood as the design criteria. Baumann Engineering provided

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geotechnical comments and recommendations on the stability of the slopes andthe feasibility of the proposed design.

This erosion control project was divided into three phases to differentiate thevarious activities and to prioritize them to ensure the high priority aspects of theproject were completed first.

When F&O started its detailed design it was found that the north side corner wasconstricting the channel. Therefore, Phase 2 was designed. Upon furtherconsideration, it was decided to complete the needed stabilization upstream ofthe corner and along Ford Branch (Phase 3).

Phase 1 included the following activities:• Bioremediation of the slide• Tree falling• Fish salvage• Creek bypass channels (dewatering)• Berm and south bank armour• Run-off interceptor channel & pipe installation• Clear slide debris• Remove log jam• Engineered log jams (4)

Phase 2 included the following activity (not part of original design or estimate):• Widen channel • Corner armour – north side downstream

Phase 3 included the following activities (not part of original design or estimate):• Corner and armour – north side upstream• Engineered log jams (2)

Bioremediation

The bioremediation portion of Phase 1 was completed by GVRD staff in thespring of 2003. This included the installation of wattle fences made out of willowcuttings. Salmonberry shrubs and red alder seedlings were planted in thetransition and deposition zones. The entire area was then hand seeded with acustom grass seed mix.

Tree Falling

This tree falling portion of Phase 1 was based on the geotechnicalrecommendations from the Baumann Engineering report. The reportrecommended the following:

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• The removal of unstable trees before they naturally failed so the rootmasses could be left intact along the wall edge, and;

• Spiral pruning to reduce the rocking action of the trees in the wind.

The tree falling took place in July, 2004.

Fish Salvage

Prior to the mobilization of heavy equipment the entire length of the affectedstream channel was delineated with seine nets; one upstream and onedownstream. The fish salvage program consisted of minnow trapping andelectroshocking and was conducted by GVRD Watershed Management staff.

Creeks & Bypass Channels

Construction started on August 3rd. The majority of the three phases werecompleted by the end of August. Minor hand work on the engineered log jamswas completed by mid-September.

A temporary access road (Figure B) was then constructed from Ford Branchdown into the stream channel.

A Cat 235 excavator was used to sort and load blasted rock at the CoquitlamBypass Quarry located at 3.3 km on the Coquitlam M/L. Two off road, articulated6x6 dumpsters were used to haul the rock riprap from the quarry to the Or creeksite (Figure E).

Four engineered log jams (Figures J – M) were constructed along the south sideby GVRD. The logs and anchor rocks were placed by excavator in the desiredlocation and configuration. The logs were then anchored to the rocks with cable.

When the south side armouring was finished, the entire disturbed area washydroseeded (Figure N). The excavator then installed another trench further tothe north to de-water the north side stream bank. The original trench wasbackfilled with the excavated instream materials.

Phase 2 armouring on the downstream north side was keyed into the existingparent material to a depth of 2 metres. To accomplish this some fine texturedlacustrine material was excavated. This material was stockpiled until trucks wereavailable to end haul the material off site.

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The Phase 3 armouring on the upstream north side was also keyed 2 metresbelow the scour zone. Once the armouring was installed the materials for 2 logjams was then placed in position. The access road remained until the excavatorhad completed both north side phases. The access road was subsequentlydeactivated.

Results

The original completion target of the project was 2003, however due to anextreme fire hazard during the ‘fisheries window’ that year, the project waspostponed. Project funds were reapplied for and the project was subsequentlycompleted in 2004. Changes to the dewatering plan were made to adjust for theactual instream flows and the fact the fine textured lacustrine deposits were veryclose to the surface in some areas.

Phase 1

The bioremediation portion of Phase 1 (Figure A) was completed by GVRD staffin the spring of 2003. This included the installation of 235 lineal metres of wattlefences made out of willow cuttings. Salmonberry shrubs (100) and red alderseedlings (100) were planted in the transition and deposition zones. The entirearea was then hand seeded with a successional reclamation mix that wouldprovide some erosion protection and allow natural succession to occur.

The results of the fish salvage program were as follows:

Table 1. Fish Salvage Summary ResultsSpecies Number Average Length

(mm)Average Weight (g)

Coho 753 56.2 2.1Rainbow trout 170 108.8 13.0Dace 301 - -

A total of 32 trees were felled from the headscarp into the slide area for thefollowing reasons:

• Site safety• Windfirming the forested stand edge• Elimination of unstable trees

The rock armoured berm was keyed about 2 metres below creek scour along itsentirety. The berm was about 120 metres long, 3-5 metres high and 4 metreswide at the top. The angle of the rock armour was about 1.5:1. A summary of theactual rock riprap volume used for this phase is as follows:

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Table 2. Summary of the Various Rock Products Installed During Phase 1Rock Product Actual Volume (m3) Estimated Volume (m3)20 mm angular 50 25

Fill & loose riprap 520 375Heavy angular 3750 3150

Totals 4320 3550

A run-off interceptor channel with two angular rock check dams was alsoinstalled behind the berm (Figure S). A 900 mm diameter steel pipe was installedabout 35 metres from the lower end of the berm to drain the interceptor channel.It was skewed and installed at an elevation that would not allow fish migrationinto the channel. About 20-30 cubic metres of slide debris from the toe of theslide (Figure G), behind the berm, were excavated and either end hauled away orplaced and spread over the top of the berm. This was replaced with someangular rock at an angle of repose less than 55%. Some of the existing instreamwoody debris was also placed on top of the berm to enhance terrestrial riparianhabitat and site biodiversity.

The downstream log jam was dropped in favour of 10 metres of bank armouring.It was determined that the log jam would have to be installed too far above thehigh water mark to create any significant habitat.

Phase 2

This Phase consisted of sloping and armouring about 60 lineal metres of thedownstream section of the north side stream bank. This was due to the fact thatPhase 1 caused a constriction in the stream channel that needed to be widened,and therefore not included in the original design. The key way that wasexcavated to install the toe of the rock armour was almost entirely comprised of afine textured lacustrine material (Figure H). This resulted in some extra haulingcosts and the generation of some turbidity that will be discussed further in thenext section. The rock volume summary for this phase is as follows:

Table 3. Summary of the Rock Product Installed During Phase 2Rock Product Actual Volume (m3) Estimated Volume (m3)Heavy angular 750 1580

Totals 750 1580

Phase 3

This phase consisted of sloping and armouring about 60 lineal metres of theupstream section of the north side stream bank. This was done to protect theexposed bank directly above the Phase 2 works and Ford Branch. The rockvolume summary for this phase is as follows:

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Table 4. Summary of the Rock Product Installed During Phase 3Rock Product Actual Volume (m3) Estimated Volume (m3)Heavy angular 750 1580

Totals 750 1580

Two engineered log jams were also installed in this section. The location of thetwo structures was as per the plan.

As per the contribution agreement, BCRP contributed funding in the amount of$97,225. GVRD provided $60,000 of in-kind contributions to this project.

Discussion

The installation of a rock berm along this section of streambank on the Or Creekis intended to minimize the production of slide debris from an active exposedslide. The installation of 6 engineered log jams, strategic placement of coarsewoody debris and the implementation of bioremediation techniques in this areawill add to the rehabilitation of this site by increasing biodiversity and enhancingterrestrial and aquatic habitat.

The construction of the log jams was conducted in a manner that resulted in lessmachine time and appeared to be safer. By first positioning the logs and anchorrocks with the excavator then having the crews assemble the structures meantthat the crews did not have to tighten the cables with heavy equipment. Thecables were simply pulled tight through the drilled holes in the logs by hand thenepoxied into the placed rock anchors.

When the Phase 2 key way was installed the excavated fine textured materialthat was stockpiled meant that the material was handled twice. As a result someresidual material remained in the channel. That material was flushed downstreamwith the first runoff event.

The amount of bioremediation that was conducted on the slide was small butappears to be providing some protection, shallow soil root strength, biodiversityand aesthetics. Adding woody debris from the falling component of Phase1 intothe slide area also added surface erosion protection, increased the roughnesscoefficient and added biodiversity to the slope. Bucking of the woody debris to layflat on the ground facilitated faster decomposition of the material. Grass seeding,either by hand or hydroseeding (Figure P) seemed to be quite effective inproviding surface erosion protection, improved aesthetics and biodiversity to theentire site.

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The existing instream woody debris that was salvaged from the channel duringconstruction was scattered on the engineered log jams and also placed on top ofthe berm. The intent of this was to enhance riparian habitat; both aquatic andterrestrial. This should be monitored for effectiveness.

Recommendations

Based on the results of this project and the discussion section of this report thefollowing recommendations can be made:

1. The project management team should meet onsite annually to reviewand discuss the effectiveness of the project design. The site shouldalso be visited by monitoring staff after significant storm events.

2. A review of the effectiveness and appropriateness of the engineeredlog jams is recommended to determine what future situations warrantthese structures or not.

3. Any future fine textured material that needs to be end hauled off siteshould be done at the time of excavation; stockpiling of this type ofmaterial should be avoided below the high water mark of the channel.

4. The status of habitat quality and plant succession on this site shouldbe monitored. Further recommendations should be provided if morework is required.

5. Effectiveness monitoring will determine the integrity and status of theinfrastructure that was installed in this area. Further recommendationsshould be provided if more work is required.

6. Remedial work (repairs and/or maintenance) should be conducted withfunds provided through a long term funding arrangement with thepartners.

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Acknowledgements

We would like to acknowledge Fisheries and Oceans (F&O) staff HaroldBeardmore, Matt Foy, Jesse Neri and Jonathan Bulcock, for providing detaileddesign services, professional advice on habitat issues and environmentalmonitoring during construction in this project.

We would also like to acknowledge members Malcolm Schulz, Bill Amos, GuyGerath, Mike Carson, Scott Stuart, Brian De Gusseme, Denis Ritchot, JohnHowell, Heidi Walsh, and Grace Santos-Ocampo of the Greater VancouverRegional District (GVRD) Watershed Management staff for their participation inthe various phases of this project, as well as Ken Bonderud from Fosters’Construction who undertook the berm construction and streamside armouring.

Finally, this project would not have been possible without the financial support ofthe BC Hydro Bridge Coastal Fish and Wildlife Restoration Program.

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References

Baumann Engineering. 2003. Geotechnical comments and recommendations onthe Or Creek slope failure. Prepared for GVRD, Burnaby. 6 pages.

Greater Vancouver Regional District Report. 1997. Sediment Source &Bioengineering Prescription for a Small Slide in the Lower Reaches of Or Creek.

Northwest Hydraulic Consultants. 2003. Hydrotechnical review of the proposeddesign. Prepared for GVRD, Burnaby. 7 pages + appendix.

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Appendix I – Financial Statement

Or Creek Bank Stabilization Financial Basis for Project

BCRP Funded GVRD Inkind Project Personnel

Prescription, design & approvals $ 2,000.00 $ 4,000.00 Faller $ 1,400.00 $ - Construction Supervision $ - $ 20,000.00 (Foreman + supervisor) Revegetation-Bioengineering $ - $ 5,000.00 Log Jam Construction $ 5,000.00 $ - Post-treatment Monitoring $ - $ 10,000.00

BCRP Funded GVRD Inkind Equipment & Expenses

Log Jam Construction $ 3,200.00 $ - Log Jam Trucking $ 500.00 $ - Rock Armour Construction $ 80,250.00 $ - Rock Armour Source $ - $ 16,000.00 Revegetation $ 500.00 $ - Revegetation-drying trailer $ 1,000.00 $ - Communication Plan $ 3,375.00 $ - Overhead $ - $ 5,000.00

Project Totals $ 97,225.00 $ 60,000.00

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Appendix II – Performance Measures

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Appendix III – Confirmation of BCRP Recognition

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Appendix IV – As-built Drawings

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