Scope of services
Verification of district meter areas (DMAs), leakage detection and non revenue water reduction step test design and implementation

Technical description
London suffers from comparatively high levels of leakage due to the age of its network, the high population density, heavy traffic volumes and soft clay soils.

Halcrow has several specialist teams currently evaluating the integrity of the district meter areas (DMAs) of central and north London.

The DMAs were designed a number of years ago and through operational and maintenance procedures their integrity has suffered.

The teams are completely reassessing the DMAs from meter accuracy, number of properties, understanding internal flows (closed/buried valves) through step and pressure testing.

Once the DMA is confirmed tight further sub-DMAs are designed and proved - known as Leakage Control Areas. These are then assessed and leakage detection programmes are targeted at those areas with most unaccounted for water.

When leakage has been lowered to an economic level the responsibility for active leakage management is returned to the client with associated documentation in order that the integrity may be maintained in future.