Theme of diploma thesis is project of small water reservoir on Rakovnický brook in cadastral Pšovlky. Water reservoir is designed to fulfil accumulation and retention function. This function will be verified by calculations in technical part of diploma thesis. There are further processed basic parameters of small water reservoir and its objects, such as safety overflow or feed–pipe. I follow applicable regulations and standards. Diploma thesis is divided into three parts. First part is the accompanying report, where identification of construction, history of territory, basic data of territory and natural conditions of territory are described. Second part consists of technical report. Hydrotechnical calculationsare part of this charter. These are included in the text for better clarity. Third part of diploma thesis is proposal and calculation of flood wave transformation.