Feasibility Study of Arbatan Dam Reservoir Restoration by Clay Blanket

Water leakage from dam reservoir and body is one of the most concerning issues in establishment of such large projects, which in addition to wasting costs brings lots of negative social and environmental consequences. One of the dams of Urmia lake catchment area, which suffers leakage phenomenon being unusable, consequently, due to not doing exact geotechnical studies is Arbatan reservoir of Heris town. Investigation of the dam establishment site shows that the dam reservoir has been placed on evaporative sediments and water penetration has resulted in formation of some sinkholes and water escape channels in the lower substrates and the dam discharge. So the aim of the present research study is to evaluate use of clay blanket for covering the reservoir floor and its restoration. To do so, after identifying subterranean features of the reservoir using SEEP/W numerical model and bent method, leakage amount of water was determined under clay blanket application state. Results of the two numerical and bent methods indicated that leakage amount of the dam reservoir covered with clay blanket are 23569 and 584000 cubic meter, respectively, within 180 days. So, with huge amount of leakage, efficiency of the method will not be effective and a good solution for the dam restoration. In general, such amount of leakage might result in repeated rapture in the dam body and clay blanket. So under such conditions, success of every investment related to this dam will confront high level of uncertainty.