Bowie’s Flat

Bowie’s Flat is a wetland project on Bridgewater Creek in Coorparoo. This project was designed to find out how effective wetlands could be in removing pollutants from urban run-off before they reach Moreton Bay.

Project Details

Background

Bowie’s Flat is a constructed wetland which lies between Leicester St and Boongall Rd Coorparoo. It receives stormwater from the catchment of Bridgewater Creek, which brings with it all the normal suburban pollutants as rain flows over roads, carparks, backyards, council parks, footpaths and the like. Bowie’s Flat was created in 2001 by Brisbane City Council, in partnership with N4C and in consultation with the local community. The goal was to treat stormwater and mitigate flooding, whilst providing habitat and a pleasant spot for a picnic.

The wetland includes structures such as trash racks, a sediment pond, vegetated wetland areas and a natural channel. These were intended to remove pollutants like sediments, nutrients, heavy metals and bacteria. At the time, it was a pioneering project as some of today’s commonly used modelling tools were not yet available.

Water level issues

Rather than a lake, the design of Bowie’s Flat wetland originally intended a low water level to allow for plenty of plants to grow on the banks; however, the system is possibly too small for the catchment it is serving, and some of the ponds may have been over-excavated. In addition, blocking of the outlet has been a problem. The water level has been too high for long periods, and the native grasses and reed beds have died. From time to time, the outlet has been cleared and new planting has been done, but the water level has varied too much.

Strategic plan

In 2012, a strategic plan was developed for Bowie’s Flat by Ashley Nicholson, landscape architect. You can download it here. It proposes a review of Bowie’s Flat, along with research and monitoring and community input. Water level and water quality should be monitored before during and after rain events. It appears that engineering solutions as well as proper maintenance will be required to make the wetland function better and make the site look more attractive, as it was intended.

Bushcare volunteers

A group of volunteers have started caring for Bowie’s Flat from November 2021. The group meets up on the first Saturday of each month, and performs maintenance through the clearance of invasive species, mulching, planting native plants and clearing the area of rubbish. Through constant upkeep, they have assisted in the reduction of pollution levels, and increased the population of native flora. Follow their Facebook page for additional information on their activities, and how you can join.

Further information about design for sustainable water management: Water by design at Healthy Land and Water.