Drinkwaterwinning in de duinen. Opzoek naar een duurzame oplossing
Belpaeme, K. (1996). Drinkwaterwinning in de duinen. Opzoek naar een duurzame oplossing. MSc Thesis. VUB: Brussel. 73 pp.
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Document type: Dissertation
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| Keywords |
Topographic features > Beach features > Dunes
Fresh water |
| Abstract |
Drinking water production in the dunes. Searching vor a sustainable solution.Production of water in the dunes has had a long history. In the Netherlands the activities started in the second half of het nineteenth century, in Belgium during the First World War. In the very beginning, the water was extracted only form the fresh groundwater lens in the unconfined aquifer underneath the dunes. This freshwater supply is however limited, and cannot be endlessly exploited. The continuous exploitation of this groundwater lens was the cause of drastic changes in the natural groundwater flow in the dune areas, leading to disruption of the original flora and fauna in these areas. This work is mainly a literature study, which has tried to describe alternatives for groundwater exploitation, and which describes the advantages and disadvantages of each technique. In the first chapter a short review of the legislative protection of the Belgian dunes is given.To discontinue or to decrease the pumping of fresh groundwater and to increase the hydraulic head in the harmed areas, water companies tried to use artificial recharge tests where water from outside the dunes is infiltrated into the dunes, and later pumped up again as drinking water. Two possible techniques are open-infiltration and deep-infiltration. The reasons for this infiltration are bacterial clean-up, homogenisation of the water quality and formation of a water storage. When using open-infiltration water is infiltrated into open basins. Because the water is infiltrated in the upper aquifer, the composition and the hydraulic characteristics of the infiltrated water will directly influence the vegetation. When using deep-infiltration water is injected into a sand layer between two unprevious layers of clay. The injected water is very well isolated from the upper aquifer, therefore the effects on the vegetation by deep-infiltration are reduced to a minimum. Drinking water production in the dune area will, whatever the method used may be, negatively influence the natural ecosystem: the installation, the maintenance and the exploitation of the infrastructure will continuously disturb the system.In the Netherlands open-infiltration and dee^-inflitration were both used. Due to the negative experiences with open-infiltration, this technique is gradually abandoned. For the moment attention is paid to developing deep-infiltration within and outside the dunes. In Belgium the Interurban Water Distribution Company of Veurne-Ambacht (I.W.V.A.) is planning to start the technique of open-infiltration in one of her production areas "De Doornpanne" situated in the dune belt of Oostduinkerke/Koksijde. The necessary permits have how-ever not yet been granted, due to mistakes in the procedures followed and the negative attitude of government agencies and environmental protection groups.The main question is for what pupose people will use the dunes: nature, water production or both. Two main arguments that should be taken into account are the uniqueness of the dune ecosystem and the potential alternatives for drinking water production on the coast. When the water production will continue in the dunes the companies will have to choose the best alternative from an ecological point of view, and co-operation with environmental pressure groups is needed to define ecological boundary conditions. |
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