Rainwater Harvesting of Some Catchment Areas in Mosul City/ Iraq by Small Dams Construction

Abstract

In semi-arid and arid areas, there is little surface and groundwater. Consequently, efforts are being undertaken to protect and collect rainwater as much as possible. When the rainfall is irregular in arid and semi-arid regions, a large portion of it is lost as surface run-off creating a water shortage that puts people at risk. Water collection is a substitute in these circumstances and is crucial. Water harvesting is the process of collecting rainfall and run-off using various storage structures, such as tiny dams, primarily for human, agricultural, and livestock use. For the construction of storage structures to impound and harvest rain and run-off water, forming surface storage reservoirs, four sites with special hydrological and geomorphologic characteristics have been identified and pointed in the drainage map of the studied areas (Tal-Kaif, Zummar, Al-Shor, and Wadi-Almur). A dam model was created using a Global Mapper and Watershed Modeling System program, WMS. Each reservoir's geometrical dimensions and the overall volume of water held behind each site's dams were measured and computed. The four sites' combined storage capacity for water behind the dams might exceed (75×106) m3. Several dam heights were selected in each basin, and the submerged areas for each height were determined to select the optimal height in each basin, i.e., 11.75, 13.9, 9.8, and 12.3 m.