One of the strategies of Revitalising Geographe Waterways is ‘Innovation and Remediation’, aiming to fast track water quality improvements in key Geographe waterways through innovative technology and remediation and by implementing key actions from water management plans. The Vasse Taskforce has prioritised investment in these projects because they address an immediate need and can deliver water quality outcomes in the short-term.
The Vasse Wonnerup Wetlands Partnership undertook removal of approximately 787m3 (around 48 dry tonnes) of sediment in the Vasse Estuary alongside Estuary View Drive in Wonnerup. The project removed sediment along a 220m stretch that is exposed over summer months when water levels are low. Build-up and exposure of black ooze sediment in this area is thought to contribute to offensive odours over summer months, impacting livability for neighbours.
A layer of nutrient-rich, fine organic sediments has accumulated throughout the Lower Vasse River with an average depth of 450mm. This sediment provides an internal source of nutrients that contributes to algal growth in summer months.
The City of Busselton is leading this project to remove sediments from the lower sections of the river. Stage 1 was completed in June 2022 and removed an estimated 630 tonnes (dry solids) of sediment between the Butter Factory Museum to the Causeway Road Bridge in Busselton. The technique used a micro-dredge and dewatered sediments using geotextile bags; the first large scale application of this technique locally within these environments. Silt curtains were erected on either side of the dredging area to prevent impacts to water quality in the rest of the river and the Vasse Wonnerup wetlands.
Stages 2 and 3 have now been funded through the City of Busselton and the State NRM program. Stage 2 will occur between the old Boat Ramp and Causeway Roade Bridge in April 2023. Stage 3 is planned for the section upstream of the Strelly Street bridge in 2023-24.
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