In the late sixties and early seventies the processes of intensive erosion prevailed in the catchment and channel of the torrent Lonjinski Potok, Serbia (Yugoslavia). As the consequence the village Lonjin and the very important road Belgrade - Loznica - Uzice, Serbia (Yugoslavia). In the period 1973-1980, significant erosion control works (ECW) were performed in the watershed and in the channel of the Lonjinski Potok torrent. As the results of this the processes of low erosion occur in the watershed and sediment transport is under limit of the runoff regime. Now, runoff regime is balanced without the floods and long drought period. According his quality water belongs to the first classe. Results of research shows that erosion control works are, also, very important factor for balanced runoff regime and water quality.

There was investigated potential erodibility of two small experimental watersheds, which belongs to the watershed of Topciderska river, Serbia (Yugoslavia), on the base of geological structure of the watershed area. The investigations of potential erodibility of watersheds were included the analysis of tectonical and every geological formation, as from viewpoint of its possible erodibility as well as of possible sediment type (load, suspended and mixed) which were originated in desintegration processes. The sediment type domination, which was produced from watershed, was confirmed from granulometric composition of sediment in experimental watersteams. The synthesis of results of this analyses is presented with map of potenatial source of sediments from experimental watersheds.

In this paper sediment production and sediment discharge and its influence on hydroenergetical potential as well as pollution of river Lim - upper flow, Montenegro (Yugoslavia), were taken into consideration. Besides of problems of sediment and water discharge protection - biological and technical measures for sanation the negative effects of erosion processes were recommended. Total annual sediment production for the river Lim - upper flow was 679,763 mE-3/year and annual sediment discharge was 312,013 mE-3/year. Such sediment (produced and discharged) has negative impact on the hydroenergetical potential and soil resources and also pollutes water with sediments and other harmful and hazardeous materials. Introduction of erosion control measures will reduce the negative effect of erosion on the tolarant level.