Pond - Mawson (Yarralumla Creek catchment)
Pond, Athllon Drive, Mawson
With four schools nearby, the new pond opposite Marist College on Athllon Drive could serve as a great location for an outdoor classroom. With this in mind, multiple rock ‘seats’ and benches have been included on the elevated viewing platform.
The pond will divert water from Yarralumla Creek and, in the long term, help improve the quality of water flowing into the Molonglo River. It will also attract a variety of wildlife including water birds.
The pond has a treatment area of 4666m2 and, when full, contains approximately 6 million litres of water (about the same as three Olympic swimming pools).
Careful design has ensured that the size of the pond and the sediment basin is proportionate to the amount of available water during low-flow periods, making it as efficient and cost-effective as possible.
A number of existing trees have been retained, mostly eucalyptus and casuarina. Some trees were removed, mostly Populus alba, a declared weed species.
Each year it will remove over 141,000 kilograms of nitrogen, phosphorous and suspended sediment from stormwater run-off.
The pond also has a natural viewing platform with seating close to the existing bike path.
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.
The establishment period may change depending on ground and weather conditions. During the establishment period, flows into and through the asset will be managed to suit the conditions and to protect and nurture the plants.
Some areas of the site may remain closed to allow for plants to establish.
During the final design phase, some changes were made to the original concept designs to accommodate underground services, community feedback and maximising water quality benefits.
- The total pond area was reduced by 14% to accommodate the surface grade, achieve a better cut/fill balance and avoid disturbing the nearby fibre optic cable.
- The stormwater diversion pit was moved away from Mawson Drive, 100m closer to the pond which resulted in significant cost savings.
- A review concluded that harvesting and reusing stormwater would not provide good value for money at this stage. However, outlet works have been configured to accommodate future harvesting infrastructure.
- The alignment and position of the maintenance access point was changed to reduce the impact on an existing stand of trees.
Find out what you can do on your own block to improve water quality in our lakes and waterways..
Landscape design plan
Click on the image to enlarge.