Assessment of Riverbed Clogging in Reservoirs by Analysis of Periodic Oscillation of Reservoir Level and Groundwater Level

In the area of Krško alluvial field, Brežice hydroelectric power plant (BHPP), with its surface water reservoir, was completed in 2017. The new BHPP reservoir dam is located approximately 7 km air distance downstream old nuclear (NEK) dam. NEK built 1970s. primary purpose to provide fresh for cooling reactor. To assess impact newly on groundwater, we performed a series data analyses prior construction. One part analysis relating from monitoring facility showed an interesting correspondence between level oscillation and groundwater nearby observation well. Based measurements taken 2000, sought estimate clogging Sava riverbed sediments reservoir. determine permeability sediments, applied geometry similar that chosen by Hantush his pumping test method. Using Fourier analysis, determined dominant frequencies hydrograph records pressure probe determination frequency, used wave equation compare influence different values hydraulic transmissivity clogged transfer oscillations For non-clogged aquifer (T, S), assumed experiments polje. We also homogeneous isotropic, as had method semipervious river beds. results obtained indicated potential estimation thickness layer which, analogy geophysics, can be called apparent thickness. This meant could basis default conceptual model rather than real measurements. presented shows using periodic piezometers, clogging, cases where periodical occur wells are near enough detect oscillations.