Water resources and groundwater quality in North Peloponnesus (Greece)

Groundwater plays an important role for urban and agricultural water supply in northern
part of Peloponnesus. Despite increasing environmental awareness in this area,
groundwater is a resource that is being stressed. Groundwater provides about 80% the
total quantity of water supply. Distribution of water resources is nonhomogeneous in this
region. In general the eastern part is semiarid, whereas the western part is supplied with
abundant water. Surface water potential in North Peloponnesus estimated to be 0.9-
1.2x109 m3 y-1. Overexploitation of groundwater and the extensive agriculture has created
environmental problems in some aquifers (sea water intrusion, nitrate pollution). Seawater
intrusion occurs in some coastal aquifers, where negative water balance has been
established. High percentage of the examined samples exceeded the maximum
admissible nitrate concentration of 50 mg l-1, set by EU for drinking water. Groundwater in
urban areas has been contaminated to varying degrees. The water quality is classified into
Ca-HCO3 type (fresh water) and Na-HCO3 or Na-Cl type (brackish waters) in the coastal
part, due to seawater intrusion. Some recommendations are made in order to safeguard
high water quality and to develop new ways of providing water source in the study area.
Moreover, an integrated and comprehensive management scheme should be applied,
aiming at sustainability of water resources and based on surface water and groundwater
exploitation, simultaneously.