Australia experienced an outbreak of algal blooms in the early 1990s that led to a concerted national program to reduce eutrophication. Most Australian States drew up nutrient management strategies which required catchment management groups to produce plans for nutrient reduction within their catchments. Most catchment management groups used the Catchment Management Support System (CMSS) to assist them in the preparation of these plans. CMSS is a simple decision support system developed by CSIRO (the national research organisation) which allows managers to assess the effects of Land Use and Land Management policies on nutrient loads. CMSS has been widely adopted by managers and community groups throughout eastern Australia and has been instrumental in drawing up many nutrient management plans. The program's success is attributed to its design features such as its simplicity of use, very low data demand, suitability for the specific institution task and the degree of documentation, training and support offered.
In this paper the application of CMSS to the Hawkesbury-Nepean Catchment in New South Wales is used to illustrate features of the decision support system, and its relevance to policy formulation.