The ACT’s Environment, Planning and Sustainable Development Directorate engaged Natural Capital Economics (NCEconomics) to undertake an ex-post economic evaluation of the ACT Healthy Waterways program. This program was aimed at improving water quality in the ACT and downstream into the Murrumbidgee River system by reducing total nitrogen, total phosphorous and total suspended solids through water quality control infrastructure, encouraging behaviour change, and improving data and knowledge.

Natural Capital Economics partnered with Alluvium and Mosaic Insights to investigate the benefits of investing in water quality improvements infrastructure, behaviour change programs and research activities. Infrastructure projects included the construction of wetlands, rain gardens, ponds and waterway restoration works. We followed an ecosystem services evaluation framework to scope the different benefits of the program. Identified key benefits included water quality improvement, amenity enhancement, improved recreation and physical activity stimulation, urban cooling and enhanced biodiversity.

We undertook a cost-effectiveness analysis, a cost-benefit analysis and a regional economic impact assessment. The cost-effectiveness analysis provided information on the most effective assets to manage total nitrogen, total phosphorus and total suspended solids.

Our study provided the ACT Government with confidence that the program has led to multiple benefits across the ACT and nearby regions and that this was an economically viable undertaking. Our finding will be used to inform policy, support efficient resource allocation as well as provide enhanced understanding about the benefits of water sensitive urban design assets.