In the paper the evaluation of influence of changes in water catchment area land use on the size of peak outflow was conducted. The investigations were conducted in Winna Góra catchment area located in Mściwojów, Lower Silesian voivodeship. The catchment area is 11.78 hectares. At present, the catchment is used as arable land, forest and meadows. In the future the area of sealed surfaces such as: roofs, roads and car parks will increase. This can contribute to the change of water balance components. Analyses has shown, that changes in the use of a catchment area lead to reduction of surface flow time from the catchment (less resistance to motion) – in effect it causes increase of the outflow volume at about 28%. The increase of the water outflow volume may have significant influence on the Winna Góra development. To counteract the results of adverse changes caused by the catchment sealing – it is recommended for the investigated area to apply a balanced approach. This would consist of retaining precipitation water in its place of origin.