Approximately 40% of the drinking water supply for South East Queensland is either sourced from, or travels through, the Mid Brisbane Catchment before being treated at the Mount Crosby Water Treatment Plant. Key risks to drinking water quality include pathogens, turbidity, chemicals and salinity. Healthy Land and Water together with Seqwater and interested landholders have come together to deliver the Mid Brisbane Water Quality Partnership Program, which aims to improve water quality and resilience in the Mid Brisbane catchment.
Source water protection programs like this one can reduce water treatment costs, improve asset life, and deliver a value for money water supply to the people of South East Queensland.
In 2017, a previously installed rock chute in a landholder’s gully in Vernor sustained damage during ex-tropical cyclone Debbie. The area directly above the rock chute was undermined with exposed geofabric and an erosion head was forming.
A second gully on the property had also been steadily eroding for some years and during the six months between July 2019 to February 2020, an estimated additional five and a half tonnes of soil eroded from the site.
The first gully project involved installing rock gabions at the top of the rock chute to flood the forming gully head and establishing vetiver grass to avoid the problem occurring again. The erosion heads in the second gully were battered, and a leaky weir was constructed from logs with a rock stilling well downstream. This floods the eroding area to a level where the slope is more gradual, reducing the risk that it will erode again.
Rows of vetiver grass and lomandras have been planted upstream and downstream of the site to assist in its stabilisation. Care will have to be taken with future grazing to ensure the vetiver becomes established.
According to Healthy Land and Water’s project manager for this project, Mark Waud, “the program has been a huge success”.
“Healthy Land and Water is getting real work done on the ground to tackle erosion, landholders are being supported and Seqwater is getting results in improving the water quality of the Brisbane River,” he says.
Healthy Land and Water is wrapping up the first three years of the Program and working with Seqwater to secure funds for the next iteration.
Click here for more information about the Program.