Summary:

In this paper we described the process of watercourses maintenance and analysed the problems involving its quality management in terms of the water-course efficiency. The watercourse efficiency is determined by running waters use and maintenance works. Both actions are characterized by good quality when the good technical condition of the river-bed, its capacity and the good ecological status are provided. River-bed capacity ant the ecological status of the running waters are influenced by the aquatic plants. Therefore control and assessment of aquatic plants abundant are major elements of the quality management of the wa-tercourses efficiency.
To identify the problem of overgrowing of running waters with plants, the lowland watercourses in the Lower Silesia were investigated during the years 2007-2009. Field studies showed, that the overgrowing of river-bed begins straight after the maintenance works. Generally the aquatic plant development is rapid. Therefore the correct watercourse maintenance demands cyclical mainte-nance works. Maintenance works comprise a lot of technical actions, which are related to each other. In this paper we showed, that each of these actions affects the watercourse efficiency. The field studies and analysis proved, that quality management of the watercourses maintenance requires establishment criteria of the process quality assessment. Criteria should consider technical and ecological aspects.