The relationship between land use and groundwater resources and quality

Groundwater has three major roles in our environment: providing the baseflow that keeps most rivers flowing all year long, maintaining good river water quality by diluting sewage and other effluents, and as an excellent source of water supply, providing over 75 per cent of the potable supply in some regions. Groundwater is intimately connected with the landscape and land use that it underlies, and most of the landscape and is vulnerable to the anthropogenic activities on the land surface above. Land use affects groundwater resources through changes in recharge and by changing demands for water. Inappropriate land use, particularly poor land management, causes chronic groundwater quality problems. Acute groundwater quality problems are common and arise from unsuitable land use and control, notably through point sources of hazardous chemicals. Current land use instruments have only been designed to address quality issues in groundwater and do not consider recharge. These instruments have been largely ineffective in protecting groundwater from diffuse pollution for several reasons including fragmentation, their general absence of teeth, and their lack of integration into the land use planning system. This paper argues for a more radical approach which would zone land according to its overall vulnerability and resilience to anthropogenic and climatic influence in order to sustainably support the ecosystem services it can deliver. Land use would be matched with the vulnerability of the soil, with geology and water, and with the whole ecosystem. The Water Framework Directive offers a mechanism to do this, but there is no evidence of enough political will to tackle the long-term conflicts between land use and groundwater.