The US EPA published guidelines for the application of ecological risk assessment (ERA) in the USA in 1998 (US EPA 1998). The process diagram derived by Murray and Claassen (1999) in an evaluation of the US EPA framework is discussed in the context of the South African National Water Act. The evaluation discusses the various steps involved in an ERA and how it can be applied in the implementation of the National Water Act. It is concluded that the application of ERA can make a significant contribution towards sustainable water resource management. Two requirements for this are the need for more demonstration projects and that capacity be developed in risk assessment and risk-based decision making.