The use of replacement cost method to assess and manage the impacts of water resource development on Australian indigenous customary economies

The value of functional and biologically diverse landscapes to indigenous societies is increasingly recognised in public debates about development pathways but rarely rigorously assessed in development decisions. Using the replacement cost method, we quantify the direct consumptive value of aquatic species and sites for indigenous subsistence in three Australian tropical river catchments where negligible data exists on indigenous water values and the extensive use of wild resources for food, art, craft and medicines. The results establish a baseline for assessing and monitoring the socio-economic impact of hydrological and ecological changes from water resource development. More than 90% of the gross replacement value in each catchment was accounted for by a small subset of high value species which could be used as integrated indicators of ecological and socio-economic change. The total value of species harvested was distributed across a large number of sites, justifying the need for a regional management approach to ensure the maintenance of diverse habitats for hunting and fishing. While ‘value’ is a cultural, context-dependent construct, studies like this one can lend legitimacy to a targeted approach to environmental and social impact assessment of water resource development proposals by calling for prioritisation of mitigation and management actions. •Aquatic species are highly valued by indigenous people of north Australia.•Replacement cost method was used to quantify aquatic species and sites of importance.•More than 90% of the replacement value comprised a small subset of species.•Less than 53% of the replacement value was represented by the top five sites.•Economic valuation assists prioritising environmental monitoring and management actions.