Cost Risk in Water and Sewerage Systems Construction Projects

Due to their complexity and uniqueness, all construction projects are exposed to a high risk. The condition for this risk reduction is an identification of risk events and an evaluation of their occurrence probability and effect.The subject of this study was the risk of an increase in the planned costs of water and sewerage systems construction projects. The data obtained from expert survey constitute the basis of the analyses. The questionnaire prepared especially for this purpose contains the list of 25 factors that generate cost risk events which can occur during construction works execution. The list of these factors is the result of literature studies, interviews, direct field observations, as well as the inspection of investment documents. These factors include the specific features of construction works such as: a large number of people involved, investment process formalization, a long duration of the investment, capital intensity, considerable material resources use, interference with natural environment, dependence on weather and ground conditions as well as topography. The experts pointed out in the survey whether they observed particular factor in their practice, and whether the factor affected the cost of the investment. The questionnaire was filled by 51 carefully selected respondents. Each of the experts had a long-standing professional experience at the managerial position in water supply and sewerage systems realization.