The aim of the WFD is to achieve good ecological status of water bodies by 2027. EU- countries are busy deciding on the measures needed to achieve this target in the last planning period. The WFD accepts exemptions to the environmental objectives in cases where achieving good ecological status is disproportionately costly when compared to the environmental benefits. However, few countries have succeeded in such an analysis and so the wish for exemptions is often not founded in actual CBA analyses. In a previous paper an approach to screening of catchments has been presented (Jensen et al., 2013).
In this new analysis, an effort has been made to improve both the cost and especially the benefit estimates. For each catchment area, the current water quality status is identified and the costs of achieving good ecological status are determined. The cost estimates include a range of non-point pollution measures in agriculture and urban wastewater (overflow and from sewage works). Benefit assessment is based on a meta analysis of primary valuation studies in the Nordic countries. The analyses are carried out for the 108 catchments included the River Basin Management Plans for Denmark.
On the cost side, the reduction target of 13,000 tN has been set in order to reach good ecological status in 2027. The national costs vary from 600 to 1100 million DKK depending on the potentials and the measures used. The highest costs are where the reduction requirements are the largest.
The benefit estimates are based on a meta function. The meta function has been tested at it shows that the transfer-errors are within the bounds of what is considered acceptable for this type of benefit transfer. The average transfer error is 13.7 % with a median of 0.7 %. The benefit results show significant variations across catchments; accordingly, willingness to pay for good water quality varies across households. Variations in aggregate willingness to pay across catchments is also attributed to the variation in number of households across catchments. The average WTP was 1313 DKK per household. Further analyses will show the cost/benefit ratio in the different catchments which will be presented.