MANAGEMENT OF GROUNDWATER IN THE SAIDA-NABAA EL TASSEH REGION, LEBANON: PROBLEMS AND SOLUTIONS

Groundwater is the main source of water in Lebanon. Problems facing successful management of groundwater in the region of Saida-Naba El Tasseh are investigated in this study. Results of the study are used to propose solutions to these problems. The study, which covered an area of 725 Km2, comprised geologic mapping, hydrogeologic field investigations, including pumping tests, and bacteriological sampling and testing of groundwater. Results of the study revealed that groundwater occurs in three major aquifers: the Sannine Aquifer, the Nabatiyeh Aquifer, and the Quaternary Deposits Aquifer. The first two are karstic fractured limestone aquifers. The bacteriological analysis indicated contamination of some wells in the karstic aquifers by untreated sewage.

Major problems of groundwater management in the investigated region are caused by the poor infrastructure of the water supply systems, which were significantly damaged during the civil war that extended for 15 years (1975-1990) in the country; the continuous increase in the population growth; administrative problems related to the water-planning authorities; the frequent electrical power outages that affect most of the regional pumping stations; and contamination by seawater intrusion and untreated sewage.

The poor condition of the water supply infrastructure has resulted in severe shortages of water. This has led to the practice of drilling unauthorized wells at random. The unauthorized wells and all private wells in the study area have no flow meters. The shortage in water is also due in part to the low prices of water, which encouraged unnecessary demands, and the rapid increase in the population growth (about 400% in the last 40 years). The major administrative problem of groundwater management is the large number of governmental water authorities. This has resulted in the lack of coordination and cooperation, and the overlap in functions and jurisdiction of the different authorities. Groundwater in the coastal parts of the Nabatiyeh Aquifer and Quaternary Deposits Aquifer is at a high risk of contamination by seawater intrusion; contamination by raw wastewater is limited to some wells in the highly permeable karstic aquifers of Nabatiyeh and Sannine. The latter is the most important in terms of groundwater production and usage.

Solutions proposed to the above-mentioned problems are given in the following. Successful groundwater management has to rely on detailed geologic and hydrogeologic characterization of the three aquifers and the use of groundwater modeling for the determination of the optimum volume of water that can be pumped annually. The existing infrastructure of the water supply systems needs to be replaced or at least upgraded. Strict groundwater legislation should be introduced to prevent unauthorized drilling of wells, mandate installment of flow meters on private wells, adopt realistic water prices to cut unnecessary demands, and protect the quality of groundwater. The latter requires chlorination and installation of sewage treatment systems, prevention of seawater intrusion by artificially recharging the coastal parts of the aquifers, monitoring of sensitive areas most prone to contamination, and zoning of the three aquifers according to their vulnerability to contamination.