Can Coastal Hydrogeological Settings on the Island of Crete (Greece) Provide Alternative Fresh Water Source?

Water resources sustainability on islands is a vital issue because of their geographic isolation and size, thus restricting many water resources management practices such as aqueducts, deep groundwater wells and reservoirs. Most common techniques of water management on islands are rain harvesting, use of shallow groundwater wells (to avoid salt water intrusion), desalination plants and external water supply by ships. Except for the rain harvesting, all the other techniques mentioned above require energy and are costly. The island of Crete, largest in Greece, might offer an alternative water supply due to its unique coastal geological structure: high mountains consisting of karstic rocks sloping toward the coast. Mountain elevations of more than 2,000 m produce strong hydraulic gradients that push groundwater into the coastal area and sea, presenting yet an untappable resources. Coastal karstic conduits and their potential use are described in detail in Fleury et al (2007) and Bakalowicz et al (2003). While freshwater discharge to the sea has been known on Crete, systematic monitoring of this phenomenon is lacking. The proposed study will assess temporal variation of freshwater discharges via long-term monitoring to establish their duration and timing, quantitative assessment of freshwater discharges into the sea to establish potential discharge rates, hydrogeologic modeling to understand the behavior and dynamics of freshwater discharges, use of earth observations from space to monitor the Cretan coastline for freshwater discharges (using temperature differences between warm seawater and cold freshwater) and assessment of the economic cost associated with constructing drains/tunnels to intercept freshwater discharges and potential cost-benefit analysis.

References:

Bakalowicz, M., P. Fleury, N. Dörfliger, J.L. Seidel. 2003. Coastal karst aquifers in mediterranean regions. A valuable ground water resource in complex aquifers. In: Instituto Geologico y Minero de Espana Publ., Technologia de la Intrusion de Agua de mar en Acuiferos Costeros: paises mediterraneos (TIAC). Hydrogeologia y aguas subterraneas no. 8, Alicante, 2, pp. 125-140.

Fleury P., M. Bakalowicz, G. de Marsily. 2007. Submarine springs and coastal karst aquifers: A review. Journal of Hydrology, 339 (1-2), 79-92