Strategic groundwater protection

Abstract: Groundwater is an undervalued natural resource that isexperiencing a large number of threats to both its quantity andquality. Different types of land-use activities releasepotentially harmful substances that may be transported down tothe groundwater and have a negative impact on its quality.Society has been gradually recognising the need for bettergroundwater protection based on land-use decisions. Theobjective of this thesis has been to develop and test aframework forstrategic groundwater protection that providesprotection at both the general resource level and at particularwells and springs (abstraction points). The frameworkhighlights protection zones with specific managementrequirements and couples these to matrices with land-useregulations. The framework is developed in a process thatinvolves major stakeholders at different project stages, inline with the intention in the Dublin Statement. The frameworkhas been developed and tested in the Managua groundwater systemin Nicaragua which is a volcanic aquifer of crucial importancefor supplying water to about 1.5 million people. The frameworkis composed of four components: (i)groundwater vulnerability assessment,(ii)estimation of potential contamination load,(iii)assessment of a protection value,and (iv)delineation of wellhead protection zones. It is possibleto extract useful information from a variety of combinations ofthe assessments. Application of the Geographic InformationSystem IDRISI was used in the analyses to facilitate theoverlay procedures. Thecontamination liability,which is a combination ofvulnerability and potential contamination load, provides aninstantaneous image of areas at risk of contamination. At theresource level, groundwater vulnerability and the protectionvalue together formgroundwater protection categories, which indicate thedegree of urgency for regulating land use. Wellhead protectionzones are delineated based on a combination of capture-zonemodelling and particle tracking. Matrices with land-useregulations are outlined and coupled to protection categoriesand wellhead protection zones. Maps accompanied by manuals andguidelines are the physical result, which can then be used inplanning and decision-making situations. A general planningprocess for stakeholder participation in groundwater protectionhas been outlined based on the experience of the work done.This process involves stakeholders at various levels throughworkshops, group meetings, seminars and short courses,depending on the planning stage and the level of expertiserequired.Keywords:groundwater protection, groundwatervulnerability, protection value, contamination load, wellheadprotection zoning, stakeholder participation, Nicaragua