18 – River and wetland health in the Lake Eyre Basin – an economic perspective 163 Using the value estimates presented in Table 18.2, economic values for the different attributes of wetlands and rivers were identified for each of the 19 catchments of the Murray– Darling Basin (Table 18.3). These values were extrapolated across households in the state in which the catchment was predominantly located, except for the River Murray where estimates were for all states and territories. These value estimates were then used to identify the economic benefits associated with the Murray–Darling Basin Plan (Centre for International Economics 2011). This involved collecting background information for each of the catchments in the Murray–Darling Basin about how much different ecological attributes were improved by the Murray–Darling Basin Plan, which included increasing water for the environment. The expected change in each ecological attribute was then multiplied by the household value for a unit change, in each of the attributes, and then by the number of households, after adjusting for non-respondents. The least conservative approach for aggregating economic value assumed that all households in the state where a catchment was located had the average sample value. Non-respondents to Table 18.2. Summary of estimates of the economic value of different ecological attributes of wetlands in the Murray–Darling Basin, based on what households are willing to pay (based on Morrison and Hatton-MacDonald 2010). Ecological attributes Description Economic value (per household) References Native floodplain vegetation Additional 1000 ha of healthy vegetation $1–5 Whitten and Bennett 2001 Morrison and Bennett 2004 Hatton-MacDonald and Morrison 2005 Bennett et al. 2008b 1% improvement in area of healthy vegetation $2.20–5.70, apart from $13.72 for River Murray Morrison and Bennett 2004 Rolfe et al. 2006 Bennett et al. 2008a Native fish species and populations Native fish species present 1% increase in native fish populations $3.30–3.50 per species $0.50–5.10, apart from $15.40 for River Murray Morrison and Bennett 2004 Whitten and Bennett 2001 Bennett et al. 2008a Bennett et al. 2008b Waterbird breeding Willingness to pay to increase the frequency of colonial waterbird breeding in major wetlands in the Murray–Darling Basin $14–34/year (increased frequency), apart from $65/year for River Murray Morrison et al. 1999 Morrison 2002 Morrison et al. 2002 Waterbirds and other species Habitat for endangered/ protected/ threatened species Number of waterbirds and other species with sustainable populations $4.3–7.4 per species $3.9 per species Morrison 1999 Whitten and Bennett 2001 Morrison 2002 Morrison et al. 2002 Morrison and Bennett 2004 Bennett et al. 2008a