ACT Healthy Waterways Project

The ACT Government Environment and Planning Directorate engaged Alluvium to develop water quality improvement solutions for six priority catchments in the ACT. The project involved an assessment of the effectiveness of existing stormwater treatment infrastructure and the identification and conceptual design of new stormwater treatment systems. The overall goal of the project was to develop and cost a range of whole of catchment treatment train options to improve water quality in the six priority catchments and thereby improve water quality entering ACT lakes and the Murrumbidgee River system.
Regard was had to the major sources of pollution in each catchment and their relative contribution to water quality. A key issue for all priority catchments was the engineered nature of the drainage systems, which have virtually eliminated any habitat or landscape value from the creek systems and exacerbated erosion in remnant natural sections. Priorities for stormwater management therefore included measures to address sediment and nutrient pollution, such as bioretention systems, wetlands and ponds, and the stabilisation of active erosion at sites in the lower reaches of some systems.
The work entailed initial site identification and feasibility studies, MUSIC modelling to identify water quality improvements associated with each option, and analysis and quantification of social, environmental and cost criteria. Final reporting on the options in each catchment included hydrology and water quality analysis results from MUSIC modelling, detailed descriptions of each option and advanced concept design sketches, including life-cycle cost estimations.