Decision-making for sewer asset management: Theory and practice

Operational decision-making for sewer asset management has hardly been empirically analysed, hampering the current challenge for cost-effectiveness in the urban drainage sector. This paper analyses how decisions for sewer replacement are actually made and to what extent complexity of the decision-making environment is addressed. Decision argumentation of 150 sewer replacement projects in the Netherlands was obtained by interviews. The decision process was analysed by the rational and streams model. The decision argumentation is a relatively wide variety of information sources, of which the majority is case-specific. Yet, decision-making does not rely purely on data analysis; it also includes negotiations between involved infrastructure managers. Then, replacement planning of a sewer asset manager depends on other public works. Consequently, individual cost-effectiveness as an evaluation criterion should be expanded to include group utility.