DETECTION OF WATER LEAKS IN THE OUIZERT DAMBY THE TEMPERATURE METHOD

Abstract

Internal erosion caused by infiltration poses a significant risk to the stability of hydraulic structures. This form of erosion is all the more dangerous because it can cause – without any obvious warning signs – a destruction of the structure when the reservoir is full.Seepage areas in dikes are often subject to erosion processes. For this purpose, it is necessary to detect and delineate infiltration zones from their first stage of development. Continuous inspection and monitoring using reliable and sensitive methods for leak detection are therefore of utmost importance.The method is easy to use, and long sections of dikes can be quickly and inexpensively tested. The temperature of the containment fluid playsthe role of a natural tracer. Infiltration of the containment fluid through the dike, causing temperature anomalies in its material, can be detected and localized fromsoil temperature measurements. This is particularly the case for the Ouizert dam, which is located in arid areas where water resources are becoming increasingly scarce. This dam, located approximately 35 km southwest of the city of Mascara (western Algeria), is known for its considerable water losses. With a capacity of approximately 100 million m³, the Ouizert dam is intended to increase the degree of regulation of the Oued El Hammam to supply water to the town of Oran and the industrial complex of Arzew, ensure irrigation of the El Habra perimeter north of Mohammadia and finally supply the Bouhanifia dam with discharges. However, this dam, which has never reached its maximum level, is threatened by water leaks through one of its shores and whose importance is clearly changing over time. Water leakage was estimated at 1 m³/s, which corresponds to a considerable volume of water lost. In this article, we present an observation of the problem of leaks through the dam of Ouizert as well as the results of a study of leak detection by the temperature method.