Multiparameter monitoring

Are there Alternatives to the DMA?

For many years water utility leakage engineers have been dividing large distribution zones into smaller areas (or DMAs) as a first step in localising potential areas of leakage. However, the DMA philosophy is not supported by all water company practitioners. With the recent surge in innovative monitoring technology, are DMAs still necessary? Let us look at the alternative technologies for monitoring networks without closing boundary valves, or, if large DMAs are already in place, some low-cost innovative flow metering technologies for sub-dividing them into smaller areas.

Malcom Farley

Multi-parameter monitoring is a technology comprising a sensor that can simultaneously measure, record and communicate bidirectional flow, pressure and noise. This system lends itself admirably to the concept of monitoring leakage throughout the entire network without creating zone boundaries. Instead, sensors are installed at key positions to create 'virtual zones'.

The MWM system developed by Martinek Water Management is one such system designed to be used in the distribution network. The three parameters are continuously monitored, measured and analysed during the night hours (between 03:00 and 04:00) and compared against a reference value. If a reference boundary value is breached - increased flow, changed flow direction, decreased pressure and/or higher noise (leak or flow) an alarm is raised (Figure 2).

The interaction between the parameters and the automaticallycalculated reference values gives an indication of where leakage is occurring. The system can be used in a DMA or in an open network creating 'virtual zones' (Figure 3).
(source: Asian Water - Dec. 2010)