Large Woody Debris Structures for Habitat Enhancement in British Columbia Rivers

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Penelope Randall
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1 Cheakamus Ecosystem Restoration Stakeholder Team Meeting #22 June 30, 2011 Large Woody Debris Structures for Habitat Enhancement in British Columbia Rivers an example from Cheakamus River Derek Ray, M.Sc., P.Geo. Barry Chilibeck, M.S., P.Eng. Squamish, BC

2 Introduction LWD self-organises in natural streams: form & function Engineered structures seek to mimic the natural function but not necessarily the natural form Variations are almost limitless but typically contain: Logs Rootwads Ballast and/or anchors Sandstone Creek, Haida Gwaii

3 Introduction LWD structure features: Typically do not require excavation avoid dewatering Ballasted structures adjust to subsequent scour Relatively inexpensive to construct Employ hand labour Can be assembled by hand in remote areas Quilla Creek, Vancouver Island

As practitioners we must design with the materials available to us and

4 LWD Structure Types Every restoration manual and guidelines document lists a variety of structures with various naming schemes. As practitioners we must design with the materials available to us and to suit the specific site requirements. Simplest structure: single log Plan Section

5 LWD Structure Types Plan Section Triangular spurs with variations Plan Plan Section Section

6 LWD Structure Types 1) Section Lateral jam built in stages all elements form triangles = strength 1) Plan 2) Section 3) Plan 3) Section 2) Plan

7 LWD Structure Types Cheakamus River, BC March, 2010

channel Often creates: underflow jam, single pieces

8 Design Considerations The importance of scale Small Stream Debris Length >> Channel Width Initially LWD spans the channel Often creates: underflow jam, single pieces Challenge: match LWD size to channel size Plan Section Summarized from Hupp, 1999

9 Design Considerations The importance of scale Medium-Large Stream Debris Length Channel Width Debris transported short distances Creates: deflection jam; lateral scour; local pool Challenge: possible to be too aggressive Plan Section Summarized from Hupp, 1999

10 Design Considerations The importance of scale Very Large River Debris Length << Channel Width Debris easily transported Creates: lateral jam; apex jam (bar) Challenge: ensuring structure stability can be an issue Plan Section Adapted from Hupp, 1999

11 Project Examples The following examples are intended to illustrate various project scales and project focus: Small Stream Sauk R. side-channel habitat Medium Stream William Creek by hand Large River S. Fk. Nooksack restoration and bank protection Very Large River Pine R. channel stabilisation

solution: lateral LWD jam Typical eroding bank South Fork Nooksack River pre-project,

12 Project Example Large River South Fork Nooksack bank protection: Eroding bank threatening public and private land Funding source tied to habitat enhancement Obvious solution: lateral LWD jam Typical eroding bank South Fork Nooksack River pre-project, July, 2009 Channel width of 30 m to 60 m Bank height of 4 m Gravel bed river Sandy/silty banks

13 Project Example Large River South Fork Nooksack Over 300 logs Approx. 250 boulders Typical log length: 10 m Typical log diameter: 0.7 m Piles for lateral stability As-Built, 2009 & 2010 S. Fk. Nooksack - completed structures, July 2009

14 Project Example Large River S. Fk. Nooksack, Feb S. Fk. Nooksack, July 2009

15 Project Example Large River Existing Conditions During Construction

16 Project Example Very Large River Pine River replace lost LWD: Pipeline ruptured on Aug. 1, 2000, spilling 6,200 barrels of oil into the river Cleanup included removal and disposal of all LWD in the affected 30 km reach Restoration included re-installing LWD jams in an attempt at avoiding destabilisation of the river

17 Project Example Very Large River Pine River LWD removed = potential reoccupation of side-channels Log jam removal site Pine River, Sept. 2000

18 Project Example Very Large River Control flow into sidechannel

19 Project Example Very Large River Post 2001 Freshet

20 Post 2001 Freshet

Demonstration Project One component of a

21 2010 Cheakamus Logjam Project Cheakamus River Logjam Project: A project initiated by BCCF BCCF teamed with NHC to provide technical input Building on the 2007 LWD Demonstration Project One component of a reach-wide approach Images from 2008 CERTC LWD brochure

22 2010 Cheakamus Logjam Project Funding support: BC Hydro Bridge Coastal Fish and Wildlife Restoration Program Cheakamus Ecosystem Recovery Fund Other funding and in-kind support: Squamish First Nation also part of construction crew Living Rivers Georgia Basin/Vancouver Island Fraser Salmon and Watersheds Program Canada Summers Job Subsidy BC Ministry of Environment

23 2010 Cheakamus Logjam Project Letters of Support: Randall Lewis, Squamish First Nation Greg Wilson, Regional Biologist, Ministry of Environment Poul Bech, Vice-President, Steelhead Society of BC Dan Cahill, President, BC Federation of Fly Fishers Brent Leigh, Deputy Administrator, District of Squamish Edith Tobe, Project Manager, Squamish River Watershed Society Carl Halvorson, Property Manager, North Vancouver Outdoor School Jack Cooley, Squamish Streamkeepers

24 2010 Cheakamus Logjam Project Permits and Approvals: Navigable Waters Protection Division Transport Canada Property owner permission (Squamish First Nation) Instream Works DFO, letter of support Instream Works Water Stewardship, Section 9 Approval

25 2010 Cheakamus Logjam Project Project Design Process: Preliminary field review (BCCF, MoE, SFN, NHC) Airphoto reach assessment Topographic/Hydrographic surveys Hydraulic analysis determine design flow 1D hydraulic model (HEC-RAS) Detailed jam design BCCF project coordination Implementation: BCCF construction with NHC support

26 2010 Cheakamus Logjam Project Site 1 Reach Assessment Rail Line Side-channel Site 2 Selected for 2010 construction Site 3 Spawning Channel

27 2010 Cheakamus Logjam Project Previous NHC Investigations last 20 years: Hydrological and Water-use studies in support of the Water Use Plan; River and fish habitat modelling in the lower river; and Various geomorphological studies looking at potential effects of BC Hydro operations.

28 2010 Cheakamus Logjam Project Design Process

35-6 Number Total Weight Required (kg) Approximate Weight per Boulder (kg) Boulder

29 2010 Cheakamus Logjam Project Length (m) Typical Root Wad Diameter (m) Design Process Diameter (m) Number Total Weight Required (kg) Approximate Weight per Boulder (kg) Boulder Diameter (m) 135, , , , Total Number Required

30 2010 Cheakamus Logjam Project Construction

31 2010 Cheakamus Logjam Project Construction

32 2010 Cheakamus Logjam Project Construction

33 2010 Cheakamus Logjam Project Construction

34 2010 Cheakamus Logjam Project June 2011

Cheakamus River October 2003 Flood Restoration Project (04.Ch.03)

Cheakamus River October 2003 Flood Restoration Project (04.Ch.03) NVOS Hatchery in flood October 2003 Canada Government of Canada Fisheries and Oceans North Vancouver Outdoor School Cheakamus River October