The article analysed increased risk of local flooding as a result of reducing the fl ow capacity of ditches. The subject matter is important because of the possibility of reducing the effi ciency of agricultural crops as a result of malfunctioning of midfi eld ditches. The methodology was based on the fundamental equations describing the hydraulic parameters of water fl ow in the river. In order to reduce undesirable phenomenon the authors propose to perform regular maintenance, pointing to the economic justifi cation of the costs incurred related to improving the fl ow capacity of flume.