ANALYSIS OF THE SAFETY LEVEL OF THE DOWNSTREAM AREA OF LOČE DAM

Abstract

Draft regulations for the assessment of the hydraulic consequences of dam failure were prepared within the VODPREG 2 project. An analysis of the safety level for Loče dam was carried out as a case study based on those draft regulations. The unlikely, but still possible, failure of Loče dam was analyzed using the model PCFLOW2D. The LIDAR records were used for geometric data, while the bottom of Šmartinsko Lake was verified by extra measurements. A partial immediate failure was assumed as the mode of failure. The reach of the flood wave, its speed, and the depth of the floodwater was calculated. The accuracy of the calculation of the maximum water level was estimated to be ±15 cm (a relative error of ±5% in the case of a maximum water depth of 3 m above the ground). The calculation was carried out at normal water level in the reservoir (Z0 = 265.4 m above sea level) and two lower water levels. A water level of Z0 = 260.0 m above sea level was identified as a safe level which does not endanger downstream villages or the town of Celje. The article also describes the necessary extent of the hydrological and technical monitoring and required refurbishment works to minimize the risk of dam failure.