Managing Shoreline Erosion

1
Managing Shoreline Erosion
Module 21
2
Erosion A Natural Process

• Proceeds very slowly
• Important part of ecosystem function

Module 22
Courtesy of Ed Klekowski
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Natural Causes of Erosion

• Wind
• Ice
• Water movement
• Wave energy
• Currents
• Changing water levels
• Rain/run-off
• Gravity

Module 23
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Human Disturbances

• Removal of shoreline vegetation
• Run-off from paved surfaces
• Boat wake

Module 24
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Human Disturbances

• Construction on or near the shoreline
• Heavy foot traffic
• Shoreline alteration

Module 25
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The Impacts of Erosion

• Loss of valuable waterfront property
• Unsafe areas
• Loss of habitat

Module 26
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The Impacts of Erosion

• Changes the characteristics of the bottom
• Reduces water clarity
• Increases water temperature
• Releases chemicals/nutrients into the water

Module 27
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Signs of Erosion

• Areas of exposed soil
• Rills and gullies
• Slumping, undercut banks
• Formation of sandbars and islands

Module 28
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More Signs of Erosion

• Cloudy water
• Stream or river becoming wide and shallow
• Receding shorelines
• Leaning downed trees exposed roots

Module 29
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How To Prevent Erosion

• Protect the natural shoreline
• Reduce run-off from impermeable surfaces
• Minimize wake from boats and other motorized
  watercraft
• Take precautions during construction

Module 210
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How To Prevent Erosion

• Limit foot traffic in erosion prone areas
• Contour and cover pathways
• Avoid alterations to water courses

Module 211
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How to Control Erosion

• 1. Identify
• Cause of erosion
• Type of erosion
• Extent of problem
• Site conditions
• 2. Select most suitable control method

Module 212
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Control Methods

• A. Natural buffers
• B. Bioengineering
• C. Hardened structures

Module 213
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A. Natural Buffer
Module 214
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B. Soil Bioengineering
Module 215
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Slope Preparation
45 11 slope ? 27 21 slope ? 18 31
slope ?
Module 216
Photo credit Rian Myers 1993
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Bioengineering Techniques above the Water

• Live staking
• Fascines (wattles/bundles)
• Brush layers
• Brush mattresses

Module 217
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Live Staking
Module 218
Courtesy of Carolyn Dindorf
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Fascines
Courtesy of Maccaferri Ltd.
Module 219

• Courtesy of Douglas Fuller

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Brush Layers
Module 220
Photo credit Environment Canada
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Brush Mattresses

Module 221
Courtesy of Maccaferri Ltd.
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Maintenance
Module 222
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Recommended Native Species

• Red-Osier Dogwood
• (Cornus stolonifera)
• Silky Dogwood
• (Cornus obliqua)
• Grey Dogwood
• (Cornus racemosa)

Module 223
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Recommended Native Species

• Pussy Willow
• (Salix discolor)
• Shining Willow
• (Salix lucida)
• Shrub Willow
• (Salix eriocephala)

Module 224
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Gathering Plant Material
Module 225
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Bioengineering Techniques In the Water

• Fibre rolls
• Brush bundles
• Plant anchors

Module 226
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Fibre Rolls
Module 227
Courtesy of Maccaferri
Courtesy of Douglas Fuller
Courtesy of Douglas Fuller
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Brush bundles
Module 228
Courtesy of Carolyn Dindorf
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Plant Anchors

• Fibre mats
• Fibre bags

Module 229
Courtesy of Maccaferri Ltd.
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Case Study
31
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C. Hardened Structures

• Break walls
• Gabion baskets
• Riprap

Module 232
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Breakwalls
Module 233
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Retiring Your Breakwall

• Dig it out
• Break it down
• Plant it

Module 234
Photo credit Cottage Life Magazine
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Gabion Baskets

Module 235
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Riprap
Module 236
Courtesy of Douglas Fuller
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Approvals

• Contact
• Conservation Authority
• Ministry Of Natural Resources
• Department of Fisheries and Oceans
• Parks Canada

Module 237
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Managing Erosion

• Practice erosion prevention
• Understand the source of erosion
• Research your options
• Make an informed decision

Module 238