Sustainable Methods for Reducing Shoreline Erosion

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1 Sustainable Methods for Reducing Shoreline Erosion Chris Randall Master s Student Natural Resources Institute University of Manitoba

2 Disclaimer For advise on specific problems relating to erosion and bank stability I recommend you consult a a Professional Engineer (P.Eng) But also talk to an ecologist!

3 Contents Understanding Erosion Conventional Erosion Protection The Bioengineering Alternative Some Examples of Bio-engineering Projects

4 Understanding Erosion -slumping Red River St Adolphe

5 Understanding Erosion -slumping Red River, Nth Dakota from Schwert 2003 A geologist s perspective on the Red River of the North: history, geography, and planning/management issues. Proceedings 1st International Water Conference, Red River Basin Institute, Moorhead, MN

6 from Schwert 2003 Understanding Erosion -slumping

7 Understanding Erosion -corrosion South Tobacco Creek, Miami

8 Understanding Erosion -corrosion Lake Winnipeg, Camp Morton

9 Understanding Erosion Overhang fractures and debris collects at toe wave or flow action

10 Conventional Techniques -RipRap

11 Conventional Techniques -concrete or lumber sea walls

12 Rock fill trenches and columns -Swan Lake cemetary

13 Environmental Impacts GHG emissions from production and transport Loss of habitat from mining Habitat loss from construction Harms wildlife migration routes Prevents natural recovery Increases invasive species

14 The Bioengineering Alternative Incorporating vegetation as a key part of the bank protection system Much more than just a landscaping scheme

15 The Bioengineering Alternative Combining both ecological principles and engineering laws merging both ecological systems and human activity for the beneficial coexistence of both Key attribute is that its resistance to the erosion increase over time

16 strength bioengineering Hard engineering time

17 techniques for stabilizing banks live staking horizontal and vertical willow bundles Increased energy and/or greater consequence of failure requires increasingly more complex and more costly solutions brush grids brush layers branch packing woven live walls live timber crib walls geogrid structures combined with erosion blanket combined with stone rip rap

18 Selecting materials Shrub willows Select multiple sources if possible Cut while dormant Can be stored if kept damp, cold and out of wind Choose stems bigger than a fat thumb Trim side branches and ends Soak before use

19 St Malo Lakeshore

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21 Riverton- Icelandic river

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25 Dormant sandbar willow poles Tightly packed willow branches 3ft minimum 6ft by 4 fence posts

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29 Minnedosa- Lt. Saskatchewan River

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31 Existing bank Natural fibre erosion control blanket 15cm Woven willow fence Live sandbar and yellow willow stakes Brush layer Notes Brush bundle layer laid at 90 to bank, staked into place Woven fence of willow branches over bundle layer Erosion control blanket laid over brush layer and wrapped up and over re-graded bank, secured in trench at top of bank. Insert live stakes at mm intervals 90cm Softwood stake

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37 Killarney- Pembina River

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39 Sandbar willow poles Sandbar willow stakes Notes 1. Re-grade bank to approx. 1 in 3 or shallower 2. Sandbar willow poles 20mm-25mm dia., >1800mm long staked in shallow trenches and covered with soil/water mix. Lower end below low water level, upper end exposed. 4. sandbar willow stakes 25-50mm dia. >1500mm long. Leave 500mm- 600mm exposed.

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46 Deloraine Lake

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49 Balaton Beach

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53 Willow Island, Lake Winnipeg

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63 Problems! Lack of water much worse on clay soils

64 Problems! Lack of water Too much water Though normal spring flooding not an issue

65 Problems! Lack of water Too much water Early Impacts Summer storms wash sand away

66 Problems! Lack of water Too much water Early Impacts Pests Impact likely worse for drought stressed trees

67 Problems! Lack of water Too much water Early Impacts Pests And more! Beaver cutting doesn t appear to affect survival

68 Thank You