The base level of leakage is the minimum level of leakage achievable in a District Meter Area (DMA) immediately after leakage surveys and repair work have been completed. It consists of small leaks and seepages (commonly referred to as 'background' leakage) but it may also include larger leaks which cannot be detected, e.g. leaks on long PVC mains.
For most Water Utilities base leakage makes up a major element of total DMA leakage. Reliable assessment of base levels in individual DMAs is crucial in Utility discussions with Regulators and to effectively target leakage detection resources.
WRc carried out this UK Water Industry Research (UKWIR) project to:
- Question the concept of base/background leakage
- Assess different methodologies used to determine base levels and recommend a standard procedure for estimating
- Assess explanatory factors for differences in base levels between different water utilities and geographical regions
- Investigate the relationships between base leakage, infrastructure condition and leakage control effort, to determine whether practical lower limits can realistically be placed on base leakage.
Understanding the causes of different base levels of leakage will:
- Improve the robustness of the Economic Level of Leakage (ELL) calculation
- Enable efficient targeting of leakage control resources.