Using a groundwater quality negotiation support system to change land-use management near a drinking-water abstraction in the Netherlands

A negotiation support system (NSS) was developed to solvegroundwater conflicts that arose during land-use management. It was setup in cooperation with the stakeholders involved to provide informationon the impact of land use, e.g., agriculture, nature (forested areas),recreation, and urban areas, on the quality of both infiltrating andabstracted groundwater. This NSS combined simulation programs thatcalculate (1) the concentrations of nitrate in shallow groundwater foreach land-use area and (2) the transport of nitrate in thegroundwater-saturated zone. The user interface of the NSS enabledscenario analyses. The NSS was validated at a drinking-water abstractionnear Holten (the Netherlands) using a spatial planning process aimed atsustainable land-use and groundwater-resource management. Two land-usescenarios were considered: a base scenario reflecting the autonomousdevelopment and an adapted land-use scenario. The calculated results forshallow groundwater provided an explicit spatial overview of the impactof historical land use and N application on the quality of abstractedgroundwater as well as insight into the impact of changes in land useand N application. Visualization of the conflicting interests ofagriculture and the drinking-water abstraction helped all stakeholdersaccept the necessary changes in land use identified by the adaptedland-use scenario of the NSS. These changes were included in thepreferred land-use management option in the regional planning process,which has since been formalized. The NSS provided system insight,scoping analyses, and education, in addition to generating quantitativeinformation on the impact of land-use functions on groundwater quality.