Rain garden - Isabella Plains (Lake Tuggeranong catchment)

Rain garden, Upstream from Upper Stranger Pond, Isabella Plains

Welcome to the biggest rain garden in the southern hemisphere.

Located in parkland beside Upper Stranger Pond, this rain garden has a treatment area of 5200m2 and, when it rains, it will treat about 1800 litres of stormwater a second before it enters Lake Tuggeranong.

The Lake Tuggeranong catchment was identified as a priority when planning for ACT Healthy Waterways first began. The ACT Government knows the community is concerned about water quality and this project focuses on limiting the amount of pollutants entering the lake.

The completed rain garden remove over 80,000 kg of nitrogen, phosphorous and suspended sediment every year before it enters Lake Tuggeranong.

Stormwater run-off is the biggest source of water pollution in our creeks and lakes, posing a risk to public health and aquatic life and threatening the many social, economic and environmental benefits our lakes and waterways offer.

A two year macrophytes (water quality plants) establishment period has commenced. Establishment period refers to the process by which a plant becomes established in a new habitat.

Design changes

During the final design phase, some changes were made to the original concept designs to accommodate community feedback, make best use of the existing terrain, reduce project costs and maximise water quality outcomes.

  • The existing open gross pollutant trap (GPT) will be extended in place of the planned additional GPT and diversion pipe.
  • The treatment area has been divided into two sections to eliminate the need to re-lay an existing stormwater pipe.
  • A fringing swale has been added to divert major surface water flows around the treatment area.

More information

Find out what you can do on your own block to improve water quality in our lakes and waterways.

Rain gardens are great for backyards as well. Learn how to build your own rain garden.

Landscape design plan

Click on the image to enlarge.

Rain garden landscape design for Upper Stranger Pond