In 2013, Bangalore Water Supply & Sewerage Board (BWSSB) undertook a project to improve water distribution system, reduce Unaccounted for Water (UFW) and leakage control in Central Division of the city covering an area of 26.5 square kilometers with 725 kilometers of the distribution network and 86,349 connections. SUEZ was entrusted with this responsibility.
This 8-years project has broadly two objectives:
- Suggest and implement system improvement works through existing system design and alterations.
- Reduction of UFW to 16% and maintain the level across all established DMAs in the project area.
Unaccounted-for Water (UFW) is the difference between the quantity of water supplied to a city's network and the metered quantity of water used by the customers. It has two components -- physical losses due to leakage from pipes and administrative losses due to illegal connections and under registration of water meters.
Since the major objective was to reduce UFW, it was necessary to know the total number of customers receiving water through that network and the exact cumulative quantity that was used by the customers. The Company successfully completed a customer survey of 91,284 properties, updated and mapped 86,349 properties with registered water connections. The survey was undertaken digitally, through tablet computer application, capturing the picture of meter and GPS coordinates among other 22 attributes. A detailed walk through survey and regular updates were carried out to map 756 kilometers of the existing and rehabilitated distribution network of GIS. 43 DMAs were designed through hydraulic modeling exercise with demand for 2025 and established with Pressure Zero Testing. Helium leak detection technique was used to detect the leaks for around 1300 kilometers. A total of 8568 leaks – 6873 visible and 1695 invisible leaks were found in the network. The leakages were fixed. House Service Connections and consumer meters were replaced.