This article represents data of the drainage system functioning at the experimental field "Radmilovac" just after its construction and eleven years later. In the first three years of the system functioning the values of drainage discharge, water table depth and soil moisture content were in the range which characterizes satisfactorily drained soil. The absence of weed control and luxinate growth of annual and perennial weed every year canal silting, solid waste disposal in the canal significantly reduced cross- section of the water flow and blocked the outflow of the drain pipes. Mean value of the water table is moved toward the higher value, with small dispersion around the mean value, which can be used as one indicator more to describe the reduced functioning of drainage systems. To enable the system functioning on the design level, some extra works, out of regular maintenance, should be done to revitalize the system. Some of the works should be: to excavate the silt from the canal, to reshape the canal drainpipes leaching, to root up bushes and trees from the bottom of the canal.