Cost-Effectiveness Analysis of Water Management Measures in Two River Basins of Jordan and Lebanon

Chekka Bay area and Amman Zarqa Basin are two complex river basins in northern Lebanon and northern Jordan respectively. Both regions are faced with growing populations, urban development and land-use changes. They also both suffer from water-resource scarcity and contrasted seasons that threaten the perennity of sufficient water supply. Decision makers may have several water-management measures in response to the issue of water deficiency in their regions, but they need simple methods and criteria for ranking the alternatives with respect to their economical efficiency. In this paper, the Cost-Effectiveness Analysis method is used for supporting decisions to optimally combine water management measures at the river basin scale. Hydrologic and socio-economic data are used for assessing the future water balance and determine the sustainable management objectives. Both supply- and demand-side measures are investigated and compared. The analysis is based on two basic metrics to assess cost-effectiveness ratios: the average annualized and the marginal (or incremental) unit cost. The results show that the cost-effectiveness ranking of alternative measures strongly depends on the selected metric. The average annualized unit cost systematically favours large scaled water measures with high costs while the average incremental unit cost facilitates the selection of smaller and costless measures reflecting the time preference for water supply.