The increasing human activity related to land utilization through intensive agricultural production as well as increasing urbanization leads to the development of various anthropogenic pollutants in the catchments. The drainage system on agricultural areas and drainage drainage in open cannal of individual drainage areas constitutes a unique system that collects all precipitation waters to the final recipient by collecting the pollutants generated on the respective surfaces and in their immediate vicinity. The same activities generate certain spotted and scattered pollutants that in most cases surface runoff end in open channels as soon as the sediment problem is created in the form of depositing significant amounts of potentially contaminated material. This dissertation analyzes the hydrological and hydraulic aspect of emergence and (non) initiation of the sediment in the melioration channels with the aim of formulating recommendations for further treatment and the process with large amounts of sediment extracted every year from the open canal network. Since the legislative framework regulating permitted sediment contamination as well as the management of invented material from the melioration channels in Croatia in development, this paper also strives to contribute to this aspect of problem solving. One of the reasons is the fact that watercourse management plans cover watercourses with a catchment area of more than 10 km2 and stand with water surface of 0.5 km2, while 80% of the length of recorded liquids and 2% of the recorded stumps are waste on very small water bodies that are in direct contact with sources of contamination, especially heavy metals. The study included a "micro-catchment" area of 1.4 ha within the lowland part of the Vuka River basin area in the period from 2013 to 2017, the main recipient channel of Drobnjak length 2.686 m. Micro-catchment selection was performed based on sediment analysis 10 potential polluted location. Its contamination shows some deviations from other European and world criteria, especially in terms of copper concentrations. Modeling of sediment pronouns caused by real rainfall and rainfall of 25 and 50 years of return period with the HEC-RAS program package showed its poor mobility in melioration channels of flatland areas, apropos the possibility of starting in exceptional hydrological conditions. Small watercourses / channels are precisely those in which pollution leaves a trail faster, and it is more difficult to return it to a natural or satisfactory state. Thus, reclamation channels become pollution tanks that are not detected by the existing monitoring. According to some of the criteria, they are included in a category that should not be disposed of on agricultural land, and in addition, contamination due to poor mobility of sediments is kept in the area of micro-basin. The analyzes made indicate the necessity of carrying out analyzes before disposal.