Management Options of a Brackish Water Spring. Case Study: Almyros Spring (Heraklion, Greece)

Case Report

Austin J Hydrol. 2016; 3(1): 1017.

Management Options of a Brackish Water Spring. Case Study: Almyros Spring (Heraklion, Greece)

Alexakis D*

Laboratory of Reclamation Works and Water Resources Management, National and Technical University of Athens, Greece

*Corresponding author: Alexakis D, Laboratory of Reclamation Works and Water Resources Management, School of Rural and Surveying Engineering, National and Technical University of Athens, 9 Heroon Polytechniou, 15780 Zografou, Athens, Greece

Received: October 05, 2015; Accepted: January 19, 2016; Published: January 22, 2016

Abstract

Management options of brackish water springs seemed to attract many researchers the last decades. The unsuitable quality of the brackish water resources is generally considered as a great barrier to their application for irrigation or human consumption. The main goal of the development of brackish spring water is to obtain a good quality status for water body. This goal can be achieved by taking measures against seawater intrusion (controlled withdrawals, increase fresh water head by dam construction) or by applying desalination methods (e.g. reverse osmosis,ε lectrodialysis). A simplified flowchart has been presented to develop the brackish spring water in coastal aquifers. The example of the Almyros Heraklion spring water (Crete, Greece) is discussed.

Keywords: Brackish water; Water quality; Karstic spring; Almyros spring; Crete

Introduction

Among the possible solutions to combat water scarcity problems in Mediterranean Region, the first priority is usually given to the sustainable use of existing water resources. According to many scientists [1-4], among the main pillars of water management strategies are: (a) to apply measures for efficient use of fresh water, and (b) to develop management of non-conventional water resources (e.g. rainwater harvesting, recycled water and brackish water). Brackish water use can be a possible solution to the water scarcity problems [4-6].

The karstic aquifers in many Mediterranean coasts are the main source of freshwater while they exhibit a very fragile behavior because these systems are prone to seawater intrusion and consequently to the deterioration of freshwater quality. Moreover, issues dealing with karstic springs seem to attract many scientists worldwide [6-8]. It is noteworthy to mention that a water mixture composed of only 5% seawater and 95% freshwater exceeds the parametric values and criteria for drinking and irrigation uses [4,6,9]. Needless to say that management problem of a brackish spring is not an exclusive matter of quantity but also of water quality.

Brackish water management options

The goals of the European Water Framework Directive [10] include, among others, the attainment of good chemical and ecological status for surface water bodies and of good quantitative and chemical status for groundwater bodies. The computation of water balances, the definition of the status of water body, the designing of monitoring networks as well as the management of exploitation plans are quite difficult tasks to be carried out in karstic coastal aquifers due to possibility of seawater intrusion.

Hydrogeological science has advanced the state of the art on seawater intrusion, but has not found a solution yet. The main goal of the management of brackish spring water is to obtain a good quality status for water body.

The main factors controlling the selection of a particular development method are: (a) geological conditions, (b) economic factors, and (c) water needs of the area. The main actions comprising a management plan of brackish water may be summarized as follows (Figure 1 & Table 1): (a) to prevent the water contamination by taking measures against seawater intrusion (upraise the fresh water hydraulic head by a dam construction at the spring mouth, to block entirely or at least partly the seawater intrusion by a special marine dam), (b) to treat the brackish water by selecting the most suitable desalination method (e.g. distillation, reverse osmosis, electrodialysis), and (c) to estimate the useful water potential of sources with varying water quality which is based on the identification of the period at which all quality parameters are within the acceptable limits which are dictated by the quality requirements of the use.