Managing Shoreline Erosion Module 2:1. Erosion: A Natural Process Proceeds very slowly Important...

38
Managing Shoreline Erosion Module 2:1

Transcript of Managing Shoreline Erosion Module 2:1. Erosion: A Natural Process Proceeds very slowly Important...

Managing Shoreline ErosionM

od

ule

2:1

Erosion: A Natural Process

Proceeds very slowly Important part of ecosystem function

Cou

rtes

y of

: E

d K

leko

wsk

i

Mo

du

le 2

:2

Natural Causes of Erosion

Wind Ice Water movement

Wave energy Currents Changing water levels Rain/run-off

Gravity

Mo

du

le 2

:3

Human Disturbances

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

Mo

du

le 2

:4

Human Disturbances

Construction on or near the shoreline

Heavy foot traffic

Shoreline alteration

Mo

du

le 2

:5

The Impacts of Erosion

1. Loss of valuable waterfront property

2. Unsafe areas

3. Loss of habitat

Mo

du

le 2

:6

The Impacts of Erosion

4. Changes the characteristics of the bottom

5. Reduces water clarity

6. Increases water temperature

7. Releases chemicals/nutrients into the water

Mo

du

le 2

:7

Signs of Erosion

Areas of exposed soil

Rills and gullies

Slumping, undercut banks

Formation of sandbars and “islands”

Mo

du

le 2

:8

More Signs of Erosion

Cloudy water

Stream or river becoming wide and shallow

Receding shorelines

Leaning & downed trees & exposed roots

Mo

du

le 2

:9

How To Prevent Erosion

1. Protect the natural shoreline

2. Reduce run-off from impermeable surfaces

3. Minimize wake from boats and other motorized watercraft

4. Take precautions during construction

Mo

du

le 2

:10

How To Prevent Erosion

5. Limit foot traffic in erosion prone areas

6. Contour and cover pathways

7. Avoid alterations to water courses

Mo

du

le 2

:11

How to Control Erosion

1. Identify: Cause of erosion Type of erosion Extent of problem Site conditions

2. Select most suitable control method

Mo

du

le 2

:12

Control Methods

A. Natural buffers

B. Bioengineering

C. Hardened structures

Mo

du

le 2

:13

A. Natural Buffer M

od

ule

2:1

4

B. Soil BioengineeringM

od

ule

2:1

5

Slope PreparationM

od

ule

2:1

6

                                     

45° = 1:1 slope

27° = 2:1 slope 18° = 3:1 slope

Photo credit: Rian Myers 1993

Bioengineering Techniques above the Water

Live staking

Fascines (wattles/bundles)

Brush layers

Brush mattresses

Mo

du

le 2

:17

Live Staking

Courtesy of: Carolyn Dindorf

Mo

du

le 2

:18

FascinesM

od

ule

2:1

9

Courtesy

of: Douglas F

uller

Courtesy of Maccaferri Ltd.

Brush LayersM

od

ule

2:2

0

Photo credit: Environment Canada

Brush Mattresses

Mo

du

le 2

:21

Courtesy of: Maccaferri Ltd.

MaintenanceM

od

ule

2:2

2

Recommended Native Species

Red-Osier Dogwood

(Cornus stolonifera)

Silky Dogwood

(Cornus obliqua)

Grey Dogwood

(Cornus racemosa)

Mo

du

le 2

:23

Recommended Native Species

Pussy Willow

(Salix discolor)

Shining Willow

(Salix lucida)

Shrub Willow

(Salix eriocephala)

Mo

du

le 2

:24

Gathering Plant MaterialM

od

ule

2:2

5

Bioengineering Techniques In the Water

Fibre rolls

Brush bundles

Plant anchors

Mo

du

le 2

:26

Fibre RollsM

od

ule

2:2

7

Courtesy of: Douglas FullerCourtesy of Maccaferri

Courtesy of: Douglas Fuller

Brush bundles

Courtesy of: Carolyn Dindorf

Mo

du

le 2

:28

Plant Anchors

Fibre mats Fibre bags

Mo

du

le 2

:29

Courtesy of Maccaferri Ltd.

Case Study

C. Hardened Structures

Break walls

Gabion baskets

Riprap

Mo

du

le 2

:32

BreakwallsM

od

ule

2:3

3

Retiring Your Breakwall

1. Dig it out

2. Break it down

3. Plant it

Mo

du

le 2

:34

Photo credit: Cottage Life Magazine

Gabion Baskets

Mo

du

le 2

:35

RiprapM

od

ule

2:3

6

Courtesy of: Douglas Fuller

Approvals

Contact:

Conservation Authority

Ministry Of Natural Resources

Department of Fisheries and Oceans

Parks Canada

Mo

du

le 2

:37

Managing Erosion

1. Practice erosion prevention

2. Understand the source of erosion

3. Research your options

4. Make an informed decision

Mo

du

le 2

:38