The article presents the results of the Mielnica watercourse bottom sediments analysis. Its typically agricultural catchment drains loess areas of the Trzebnica Hills. The material sampled represented different sections of the watercourse flowing through: headwaters and areas located on un-built-up grounds among meadows where water flows very slowly and often stagnates locally, rural built-up area, grounds located below built-up area where, after its tributary inlets, a bigger amount of the water flows as a compact current. Moreover, samples representing sediments developing at the bottom of a ditch discharging water from a pond were included in the analysis. It was found that the granulometric composition and the properties of sediments at the watercourse were conditioned by the catchment soil cover, anthro-popressure influences and hydrological conditions of the individual watercourse sections. Although the content of biogenic elements and heavy metals at the bottom sediments of built-up and lower located sections has risen, they are not dangerous for organisms in the watercourse and in ponds alimented by its water.