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Shoreline Habitat Enhancement

JOHNíS WALK LAKESHORE PROJECT

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Implementation

Monitoring

Location: Along waterfront in Johnís Walk Subdivision, Nelson, British Columbia

Client: Subdivision developer

Objective:  Establish riparian vegetation to enhance fish habitat, reduce sediment delivery and stabilize eroded bank sections along the West Arm of Kootenay Lake.

 

The Johnís Walk subdivision is located on the former Kootenay Forest Products plywood mill site in the city of Nelson. Based on the Federal Department of Fisheries and Oceans requirement, in order to obtain approval for residential sub-division, the developer had to provide enhancement of shoreline fish and wildlife habitat. Terra Erosion Control Limited was retained to develop and implement a shoreline reclamation / habitat enhancement prescription for this area.

 

The shoreline treatment is approximately 580 m in length, with banks ranging from 35 to 80% in slope gradient. A pedestrian pathway runs along the top of the bank. A small stream (Anderson Creek) also enters Kootenay River along this section of shoreline; the banks along the lower reach of this stream were also treated.


 

 
 
 
Johnís Walk Shoreline before treatment,
February 2005
John’s Walk Shoreline before treatment, February 2005

Peninsula on Johnís Walk Shoreline before treatment, February 2005

Peninsula on John’s Walk Shoreline before treatment, February 2005

 

Johnís Walk Shoreline before treatment,
February 2005

John’s Walk Shoreline before treatment, February 2005

Johnís Walk Shoreline before treatment,
February 2005

John’s Walk Shoreline before treatment

 
Lower reach of Anderson Creek before treatment, February 2005

Lower reach of Anderson Creek before treatment, February 2005

Implementation: 

The prescription developed for this area was implemented in April 2005; it included the use of brush layers and live cutting pockets in riprap. Planting of structures was machine assisted using an excavator. Straw wattles were also installed in some areas to control surface erosion. Prior to their installation, these wattles were used as temporary sediment barriers during construction. The area was also hydro-seeded with a mixture of native grasses and legumes, and planted with a native rose species (Rosa acicularis).

Live cuttings used in soil bioengineering structures were collected locally in spring 2005, and composed of a mixture of Willow (Salix bebbiana / scouleriana / exigua) and Red Osier Dogwood (Cornus stolonifera).

 
Machine-assisted installation of brush layers,
April 2005

Machine-assisted installation of brush layers, April 2005

Machine-assisted installation of brush layers,
April 2005

Machine-assisted installation of brush layers, April 2005

   
Placing live cutting pocket into riprap,
April 2005

Placing live cutting pocket into riprap, April 2005

Live cutting pockets in riprap,
April 2005

Live cutting pockets in riprap, April 2005

   
Straw wattle used as temporary sediment barrier during construction, April 2005

Straw wattle used as temporary sediment barrier during construction, April 2005

Straw wattles installed between brush layers to control surface erosion, April 2005

Straw wattles installed between brush layers to control surface erosion, April 2005

   

Monitoring:

During the summer of 2006 weed invasion, mainly Alfalfa (Medicago sativa), was a problem on this site necessitating manual weeding treatments. The seed source for the seeds is assumed to be within the imported construction fill materials.

 

As of spring 2007 the survival and growth of brush layers, the bulk of the structures installed, was assessed as fair to good. Although a portion of the live cutting pockets placed in riprap were growing well, they did poorly overall. Weed invasion was still a problem, but becoming less so as the Willow and Dogwood are emerging in height growth. Overall the objective of establishing riparian vegetation on this challenging site (due to heavy weed competition) was accomplished.

The site was further monitored in 2010 and 2014.

Growth, June 2005

Growth June 2005

Growth, June 2005

Growth June 2005

 
Growth, September 2005
Growth September 2005

 

Growth ďCornus stoloniferaĒ, September 2005

Growth September 2005

Growth, September 2005

Growth September 2005

Growth, September 2005

Growth September 2005

   
Growth of pockets in riprap, September 2005
Growth of pockets in riprap September 2005
 
Growth after manual weeding treatment,
November 2005

Growth November 2005, after manual weeding treatment

 
Growth, August 2006

Growth August 2006

   
Johns Walk shoreline, spring 2007

Johns Walk shoreline spring 2007

Growth, spring 2007

Growth spring 2007

   
Growth, spring 2007

Growth spring 2007

Anderson Creek, spring 2007

Anderson Creek spring 2007

   
Growth next to Anderson Creek, spring 2007

Growth next to Anderson Creek spring 2007

Shoreline, spring 2007

Shoreline spring 2007

   
Anderson Creek, summer 2010

   
Growth, summer 2010

   
Lower reach of Anderson Creek before treatment, February 2005

Lower reach of Anderson Creek before treatment, February 2005

Lower reach of Anderson Creek after treatment,
summer 2010

   
Field tour, fall 2014
Field tour, fall 2014

 

 

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Shoreline Habitat Enhancement