Estimated total value of stormwater assets across Greater Melbourne – including hydraulic, water quality and environmental assets

Systems Analysis quantifies urban stormwater resources and market mechanisms for stormwater and environmental management

Presentation Dr Peter Coombes at Stormwater 2018 conference at 2:00 pm on Tuesday 9 October 2018.

This research project builds on previous publications by the author that utilised a Systems Framework of historical big data from government agencies and utilities to identify the water and stormwater benefits of property scale water conservation measures for Australian cities. Bottom up systems analysis is used  quantify the stormwater resources and economic value of  stormwater infrastructure for Greater Melbourne.

This project combines additional spatial and temporal detail from the Australian Bureau of Statistics (ABS), Bureau of Meteorology (BOM), utilities, government agencies, local government and latest research in the Systems Framework to quantify the stormwater resource and associated impacts throughout Greater Melbourne. The Systems Framework for Greater Melbourne was enhanced by the addition of higher resolution spatial detail of demographic, socioeconomic, land use, local observations and economic information.

The results for the enhanced systems analysis were combined with local and regional costs of stormwater management that include infrastructure, amenity, waterway health and recreation actions. This process is used to estimate the economic and infrastructure requirements for management of urban stormwater runoff, and to develop a new market mechanism for pricing stormwater and environmental management services via impervious area tariffs.

The total value of stormwater infrastructure for the Greater Melbourne region ranged from $20,600 million in 2010 to $40,050 million in 2050. The magnitude of additional urban stormwater runoff volumes from Greater Melbourne ranged from 405 GL in 2010 to 700 GL in 2050. Total annual costs to manage stormwater runoff ranged from $1020 million in 2010 to $2003 million in 2050. The impervious area tariff varied from $0.67/m² to $1.36/m² across Greater Melbourne (average value of $0.86/m² and $583/property) and generated decreased directly connected impervious areas, stormwater runoff and management costs.