Modelling land-use scenarios to reduce groundwater nitrate pollution:: the European Water4All project

The Water4AIIproject funded by the EU Inter-regIIIB programme aimed to demonstrate groundwater protection in the context of spatial planning and the implementation of the EU Water Framework Directive. Through a series of workshops, the four partner countries (Denmark, Germany, the Netherlands and the UK) developed a handbook containing an approach for risk-based land and water management to reduce diffuse pollution of groundwater from agricultural sources. Best practice guidelines were catalogued as a matrix of compensated and non-compensated 'soft' to 'hard' measures and were supported by illustrative case studies. The Water4AII project also showed that spatially targeted measures can have wider benefits as part of a 'whole landscape' approach to planning and management. As an example, this paper explores a set of theoretical land-use scenarios, developed in consultation with stakeholders, which could potentially decrease nitrate concentrations in the regionally important Lincolnshire Limestone aquifer in eastern England. The results of a combined export coefficient and numerical groundwater modelling approach showed that a decrease in groundwater nitrate concentrations can be achieved over several decades with the implementation of a groundwater protection zone in which there is a significant element of land conversion from arable to woodland and grass. Hence, a long-term commitment to land management is required if the alternative and expensive end-of-pipe water treatment is to be avoided.