Abstract
Scarcity of water resources in the Middle East represents a prime factor in the stability of the region and its economic development and prosperity. Accordingly, augmenting water is considered very important. Therefore, building of dams is an important mean to achieve such a goal. Despite the fact that number of dams had been built but maintenance operations and reduction of siltation rates are still not up the standards. Two small reservoirs, north West Jordan, were investigated. Sad Wadi Alarab reservoir constructed in 1986 (storage capacity of 20x106 m3). The second, Alghadeer Alabyadh, was constructed 1966(storage capacity 7 x 105 m3). The actual storage capacities of these reservoirs were calculated using echo-sounding traverses. Data obtained were used in special computer software to construct the bathymetric maps and calculate the existing storage volume. The results showed that the reservoir storage capacities were reduced at an average annual rate of 0.3 x 106 and 1.7 x 104 m3 respectively. This implies that Sad Wadi Alarab reservoir will be filled with sediment within 38 years, while Alghadeer Alabyadh reservoir is already filled with sediment now. Bottom sediments of the reservoirs were collected and analyzed. In all the cases, sand, silt and clay were the dominant sediment components.