Based on Cyprus’ geographical position one would expect that it would be an extension of Nekev desert, with arid to semiarid climate. The differential uplifting of Troodos, however, brought about through complex geological processes, directly influenced the climatic conditions of the island, particularly rainfall. Therefore, average annual rainfall in the Troodos Mountain is of the order of 1.000mm while in the lowlands of 300mm and with the absence of rainfall for nine months or more, there are strong features of arid climate.
Water resources, both surface and underground, constitute a vital commodity for the growth and progress of human kind. Thus, its availability always governed the foundation of new settlements, from ancient times to the recent years.
The foundation of the first settlements in Cyprus was based on the exploitation of spring and river flows. Since the Neolithic times, Cypriots have realized the scarcity of surface waters during the dry seasons and therefore, they initiated groundwater exploration.
The extensive copper extraction (3rd millennium B.C.) resulted also to the overall development of the island giving also rise to population growth and, consequently, to water demand increase. These demands were at first covered by springs and later on by dug well, a practice which continued through the Hellenistic period. During the Roman and Byzantine periods great aqueducts were also constructed such as the one of Salamis, which supplied the city with water from the Kythrea springs. During the Ottoman period, the construction of “Lagoumia”, a chain of wells interconnected through a tunnel, via which groundwater was driven to the surface has been developed.
The systematic pumping of aquifers commenced by the end of 19th century coinciding with the import of windmills and continued later on with the drilling of bore holes. The very first (percussion) rig was imported in 1920. By 1950, the practice of borehole drilling was already established thus intensifying the exploitation of the known aquifers. Eventually, thousands of irrigation boreholes were drilled, unfortunately most of them without any control.
The exploitation of groundwater for irrigation contributed in the replacement of non-irrigated with irrigated crops, such as the citrus plantations in Morfou and Ammochostos. The growth of irrigated agriculture has resulted, however, to the gradual inversion of the water balance.
Therefore, seawater intruded in the majority of the coastal aquifers, groundwater levels lowered and borehole yields reduced. The ascertainment of a negative water balance in many aquifers in conjunction with the increased water needs, have led the State to the design and construction of major waterworks such as dams, water channels, river ponds and, recently, desalination plants. Furthermore, the exploitation of the aquifers in the Troodos ophiolites, commenced; it was made possible because of importation of contemporary and high capacity drilling rigs.
Type of aquifers
In Cyprus there are three types of aquifers. The first one is the clastic aquifers and they are mainly developed in river and deltaic deposits as well as in old marine terraces. In these aquifers, groundwater fills the pore space between the sand arid gravel grains. In the second class belong the karstic and pseudokarstic type aquifers. The former are associated with carbonated rocks such as limestone, dolomite and marble while the latter mainly with gypsum. In these types of aquifers, groundwater takes up the voids (caves) which are created from the dissolution of such rocks. The fractured aquifers represent the third class of aquifers in which water fills up the space created from the fracturing of the sound bedrock-mass (fracture zones). The productivity of these aquifers depends mainly on the lithology, the extend of tectonic fracturing and the presence of (secondary) clay minerals.
The most important clastic aquifer is that of the Western. In the area of Morfou (Mesaoria) it is mainly developed in the alluvial deposits of the torrential river Serrahis. Its recharge results mainly from the flow of Serrahis tributaries which originate from the north-western part Troodos (Peristerona and Akaki rivers). However, because of overpumping, a negative water balance has been developed and consequently, groundwater levels have been lowered. Salinity is also increased, in a great part of the aquifer. Other notable clastic aquifers are those of South-Eastern Mesaoria (Kokkinochoria), Akrotiri and the Pafos coastal zone.
The most important karstic aquifer is that of the Pentadaktylos Mountain. It is developed in limestone, dolomites and marbles. Prior to its exploitation through boreholes, ground water recharged through the known overflow karstic springs (Kephalaria), like the one in Kythrea village. Pseudokarstic aquifers occur in gypsum of the Kalavassos formation such as the one at Maroni village of Larnaka District as well as at Yiolou-Letympou villages in Pafos District.
Finally, the fractured aquifers are mainly developed in the Troodos ophiolites. The most promising hydrogeological conditions are observed in gabbro while in the lavas are the poorest. Similar type aquifers are developed in the massive chalks of the Lefkara formation.
The climatic conditions of Cyprus render great importance to its groundwater resources, towards the development and prosperity of the island. For this purpose, emphasis is placed on research, exploration, monitoring and protection of groundwater resources and for meeting water supply needs. In addition, the relevant provisions of national and community legislation relating to the protection of waters are implemented.
Due to prolonged droughts, which often occur in Cyprus, hydrogeological investigation focuses on drilling new wells to meet water supply needs in mountainous and semi-mountainous communities, which are not connected to major state water projects. In addition, the drilling activity aims to replace existing water supply wells, the water of which differs from the relevant quality standards. Such drilling activities are done by the Geological Survey Department’s drilling crews, as well as through outsourcing.
Systematic monitoring and evaluation of groundwater quality is done in the context of the implementation of the provisions of EU and National legislation. The Department also operates a telemetric monitoring network as well as other networks.
In addition, studies are carried out to implement the provisions of KDP 45/1996 of the Law 106(I)/2002, relating to the delineation of protection zones for all water supply wells.