Council trials new passive irrigation solution
Date published: 4 October 2022
A new Water Smart Tree Planting project at Heatley will test three different designs of passive tree irrigation solutions to beautify the streetscape and increase shade while helping Townsville City Council integrate methods to improve stormwater treatment before it reaches the Great Barrier Reef.
The project is being delivered by Council with support from the Queensland Government’s Reef Water Quality Program and is a trial to help inform the development of the Bohle River Catchment Offsets Roadmap, improving stormwater runoff before it reaches Townsville’s local waterways, wetlands, reefs and seagrass beds.
Community Health, Safety and Environmental Sustainability Committee chairperson Maurie Soars said the project involved trialling innovative roadside structures for diverting stormwater and planting 11 Northern Australian native dry tropics trees known locally as Red Condoo (Mimusops elengi) to utilise the runoff water and uptake nutrient, along about 160m of Mill Dr.
“In its 2021-2026 Corporate Plan, Council committed to bolstering Townsville as a sustainable destination that embraces and participates in recreational activities, which is why it’s essential that we do our part to protect our land and the 180km of coastline that connects Townsville to the Great Barrier Reef,” Cr Soars said.
“This project will not only provide the community with leafy trees, which will beautify the streetscape and offer shade to help cool the area, but it will also help test three different designs of passive tree irrigation solutions to improve tree health and resilience.
“The structures will capture stormwater which would ordinarily run-down drains and into the Bohle River to instead irrigate the trees. This passive irrigation method removes the need for long term potable water use, meaning we can use any available runoff and help filter it to improve water quality flowing to the Great Barrier Reef.
“Stormwater runoff contains nutrients and sediment which negatively impacts waterways, as well as the corals and seagrass in our in-shore reef areas.
“The Bohle Catchment Water Quality Offsets project is testing new and innovative ways to offset polluted water that is generated in our homes and usually treated by our water and wastewater treatment plants. In the long run, learning to invest in this type of green infrastructure and apply innovative solutions can directly offset the need to upgrade water treatment solutions and meet other key environmental outcomes for our city streets and improve liveability of our neighbourhoods.”
Cr Soars said the trial would run for at least 12 months and Council officers would use the data to decide whether the irrigation methods could be used in the future.
“Council is installing soil moisture sensors along this stretch of trees, which will help us gather data about how well the passive tree irrigation is working. This data will help inform whether the methods are suitable for future use in the dry tropics on other streetscape plantings across the city,” he said.
“We are embracing our dry tropical identity and I’m looking forward to how this innovation can further Townsville as a water sensitive city and protect our wonderful natural assets into the future, providing cooler, more attractive landscapes for the people of Townsville.”
Planting and passive irrigation works between Marsh St and Narangi St are expected to be complete on Wednesday October 19, weather and conditions permitting.