average annual rates of ground-water recharge (1,534 million m³/yr) and surface water flow (1,429 million m³/yr) are renewable resources. Unfortunately, these two water sources together cannot provide the total annual renewable water resources of the study area. As already noted, water moves from aquifers to streams (as base flow) and also from streams to aquifers (as recharge of stormwater runoff). An apparent attempt to reconcile all these factors has been made by the Multilateral Working Group on Water Resources (CES Consulting Engineers and GTZ, 1996). Although their definitions and methods are unclear, they estimate that annual average renewable water resources in the study area are 2,600 million m³/yr, consisting of 1,400 million m³/yr of ground water and 1,200 million m³/yr of surface water (Table 2.2). It is not clear how the 175 million m³/yr of ground water that discharge into the upper Jordan River and Lake Kinneret/Lake Tiberias/Sea of Galilee (Table 2.2 in CES Engineers and GTZ, 1996) are accounted for. An alternate calculation of renewable water resources, recognizing that there may be differences in accuracy of field data, would be to subtract the 175 million m³/yr from the total annual ground-water recharge (estimated in this report to be 1,534 million m³/yr), because it is eventually accounted for (and used for water supply) as surface water. This calculation yields an annual average renewable water resource of 2,788 million m³/yr (Table 2.2). Development of the total renewable resource, whether 2,600 million m³/yr or 2,788 million m³/yr, would be highly impractical because of the difficulties inherent in capturing all the storm flows.

The large amount of water stored in aquifers that could provide supplies in excess of natural replenishment is not considered in the above estimates of available water resources. Although short-term use of such storage to moderate the temporal variation in recharge is a standard water management practice, long-term and continual use of storage, or ground-water mining, would seem to be inherently a nonsustainable development. Use of fossil ground water is also nonsustainable, and this