The design option appraisal stage of new water industry capital investment projects involve greater levels of complexity than those generally encountered in other stages of the design process. It is at this stage that the issues related to sustainable development will be introduced, as decisions are multi-stakeholder and therefore decision criteria that reflect the views of a wide range of stakeholders with a range of different viewpoints need to be incorporated. This paper describes a case study which maps information flows, identifies decision criteria and evaluates the extent of stakeholder involvement in the design stage of a major UK wastewater system project. A mapping technique was developed to document and represent the flow of information during the decision making process. An in-depth study of the information flows enabled the researchers to establish the extent to which sustainability criteria were actually used. This was compared with recognised sustainability criteria identified in previous research involving the authors to allow an assessment of the effectiveness of stakeholder representation. Recommendations are given regarding ways of improving stakeholder involvement in water industry asset investment decisions
