IWRA Proceedings

AbstractABSTRACT The phenomenon of the water's escapes on the level of the dams results by considerable into invaluable water and rare losses and also in very serious threats of the stability of the hydraulic works. Moreover, more the share of the stoppings are subjected to a loss of capacity due primarily to three phenomena to knowing: water leakages, the silting of reserves and intense evaporation. In Algeria, we listed approximately fifteen stoppings having losses by escapes which exceed 1 million m3 per year for each one, among these stoppings six have a volume of escape higher than 5 million m3 . Due to the non existence of a better site and the establishment of the dam Ouizert in an unfavourable site with the storage of water and favorable to the water leakages, this stopping is strongly prone to this problem and its loss of capacity is in evolution because of the increase in the water leakages. In spite of the grouting curtain which were carried out along the axis of the dam and which allowed the suppression of the right bank water leakages, the problem of the water losses through left bank of the stopping towards the downstream always remains. The dam ouizert is Located at approximately 35 km in the Western – South of the place head of the wilaya of Mascara. It has a total capacity of 100 million m3 , it is intended to increase the degree of regularization of the Wadi El Hammam for the drinking and industrial water of Oran – Arzew, the irrigation of the perimeter of El Habra located at the North of Mohammadia and to feed the dam Bouhanifia by the lâchers. However, this stopping is threatened by the escapes through the left bank in clear evolution in time. The stopping has never reached its maximum level, since the lost volume generally borders the value of 1m3/s. We present in this study the assessment of the total water the total losses of the dam Ouizert while trying to show the impact of these escapes on losses on the level of this stopping especially which we considered interannual the volume of the escapes average at 10.42 hm3. From where we can conclude that the water leakages are the principal cause in the increase in the total losses of the dam Ouizert beside the accelerated silting of reserve and intense evaporation.