Participative decision-making to identify nutrient pollution sources and potential abatement actions

Computer-based models and Decision Support Systems have become standard tools for water quality management, and many are used by policy planners. Most models are developed in a research environment, have stringent input data requirements, and are becoming increasingly complex. In the early stages of policy development, managers may prefer quick and less accurate solutions to decision problems, and often require simple and flexible models that function as screening tools. In this paper we describe a modelling and participative decision-making activity aimed at identifying nutrient pollution sources and prioritising potential abatement actions for a river basin in western Sydney, Australia. A simple GIS and spreadsheet based export coefficient (EC) modelling approach was used to structure and analyse the problem, the assumptions and application of which were collaboratively explored with a panel of experts. The approach was effective in bringing together a group whose functioning had been impeded by uncertainty and indecision. The simplicity, transparency and flexibility of the approach gave structure to the decision-making problem and empowered the panel by providing a common language with which to collaboratively explore and evaluate prospective solutions.