Lake Coogee Rehabilitation

Overview

  • Client:Tokay Property Developments
  • Locality:City of Cockburn
  • Summary:Implementation a Wetland Foreshore Management Plan for a portion of Lake Coogee commencing in 2012. Extensive weed control required for problematic species, followed by planting of 48,000 wetland seedlings.

Location

Lake Coogee

Lake Coogee

Topsoil being scalped - note high concentration of Castor Oil weeds in foreground

Before revegetation activities

The Brief

In 2012 Tranen was commissioned to implement a Wetland Foreshore Management Plan for the rehabilitation of a portion of Lake Coogee, adjacent to a small new subdivision.

Lake Coogee after revegetation

After revegetation

Constraints & Issues

  • The site was a highly degraded wetland, dominated by problematic weeds.
  • Some area are seasonally inundated with water.
  • The ground was hard along one site boundary due to construction of a limestone wall.

Our Management Approach

  • The upper 100 mm of the site was scalped after herbicide application to remove dead vegetation and weed seed contained in the topsoil.
  • 48,000 wetland seedlings were planted.
  • Tree guards were installed around all trees and shrubs to obviate herbivory and facilitate seedling establishment.  Rush and sedge species did not require them.
  • In hard areas, planting holes were augured to facilitate planting and loosening of soil to assist root penetration.  Wet areas were progressively planted as winter water levels receded.

The Outcome

  • In 2015 the completion criteria were achieved, on time and within budget.  The site was then handed over to the City for future management.
  • Forward planning, intensive site preparation and follow up weed control were the keys to success.
  • Plant density was significantly higher than expected, and weed levels were low throughout the life of the project.