Reef Catchments has been awarded funding from the Queensland Government DEHP to study the water quality benefits of constructed wetland treatment trains. The study ran from 2017 to 2020.
Treatment trains use natural processes to eliminate runoff pollutants like sediment and nutrients, ensuring cleaner water to the catchment, rivers and ultimately the Great Barrier Reef.
Constructed wetland treatment trains use multiple chambers to treat water as it moves through the individual structures or basins. Included within the structures is a shallow macrophytes zone where reeds take up nutrients for their own growth. A biofilm, similar to an algae around the reeds, and the reeds themselves, also use nutrients for their growth, removing excess from the water. Within the design can be a deep chamber which landholders can utilise to pump extra water to irrigate crops, providing good production benefits. A larger biodiversity wetland area also provides a native wetland ecosystem for fishing and detains water on the property for as long as possible before entering the receiving waters.
Water Quality Improved
Past monitoring indicates these structures improve water quality while also increasing water availability for growers.
The difference between pollutant levels from the inflow and outflow of the two treatment trains will be studied, then compared against traditional sediment basins and standard cane drains. Reef Catchments will be measuring pesticide, sediment and nutrient levels to gain a better understanding of the effectiveness of these multiple basins.
“If this is a solution which gives the farmer more access to irrigation water, while also providing better water quality outcomes, we’ll be advocating to build a more of these in the region,” said Chris Dench, Reef Catchments Coordinator of Water, Waterways and Coasts.
This is a Reef Catchments initiative, made possible through funding from the Queensland Government Department of Environment and Science.