CMSS is an appropriate tool for any group or agency involved with setting land use policies and developing land management strategies at a catchment scale, with the primary goal of maintaining and improving water quality.

It is particularly suited to use in stakeholder workshops as it can be set up very quickly to provide a quantitative evaluation of alternate catchment actions being considered by the workshop.

CMSS is not complex! It has been designed specifically so that it can be applied to any catchment by people without a high level of computing expertise. Inputs are minimal and are:

• the distribution of land uses in the catchment
• the typical average annual generation rates for nutrients in that catchment, and
• some simple data on the proposed management practices.

Changes in land use and application of the management practices are easily expressed as policies.

The original CMSS was developed as a policy analysis tool in the Onkaparinga catchment of South Australia in the early 90s. Since then it has been used extensively throughout Australia, mainly by regional and catchment management groups.

At national level, it is an accredited estimation tool for the National Pollutant Inventory (http://www.npi.gov.au).

Two documented CMSS applications are:

• Cuddy, SM, F Marston, B Simmons, JR Davis and T Farley (1994) Applying CMSS in the Hawkesbury-Nepean Basin. CSIRO Division of Water Resources, Consultancy Report 93/37, Canberra.
• Joo, M, VH McNeil, E O'Brien and R Fearon (2000) Nutrient Emission Modelling in the Dawson River Basin using CMSS. Report DNRQ00142, Queensland Department of Natural Resources, Brisbane.

CMSS has been designed for the typical strategic policy planning process and is not intended to be a substitute for detailed water quality models. It is a useful first-cut tool for any catchment water quality investigation. It comes with extensive supporting material to assist with catchment description and derivation of appropriate generation rates.