3.2.1 Water supply system analysis

Summary of actions

• Assemble a team with appropriate knowledge and expertise.

• Construct a flow diagram of the water supply system from catchment to consumer.

• Assemble pertinent information and document key characteristics of the water supply system to be considered.

• Periodically review the water supply system analysis.

Effective system management requires, first and foremost, an understanding of the water supply system from catchment to consumer. Each element of the water supply system should be characterised with respect to drinking water quality and the factors that affect it. This characterisation promotes understanding of the water supply system, and assists with identification of hazards and assessment of risks to water quality.

A team with appropriate knowledge and expertise should be assembled to carry out the analysis. The team should include management and operations staff from the drinking water supplier as well as representatives from relevant agencies. In most cases, consultation with other agencies will be required for the analysis of catchments, which should include the potential impacts of land uses on water quality and stream and river flows. Health and other regulatory agencies should also be involved.

A generalised flow diagram should be constructed describing the water supply system from catchment to consumer. The diagram should:

• outline all steps and processes, whether or not they are under control of the drinking water supplier;

• summarise the basic characteristics of each component;

• make explicit any characteristics that are unique to the system;

• be verified by field audits and checked by those with specific knowledge of the system.

The water supply system analysis should be reviewed periodically to incorporate any changes that occur, for example in land use, treatment processes or consumer distribution.