Not many people know that the drinking water pipelines in Bangalore were laid over 70 years ago and their replacement is long overdue. Water pipes in the old areas of the City like Malleswaram, Chamarajpet and Chickpet were laid 50 years ago.
Not surprisingly, the pipes are corroded and leaking, thereby resulting in millions of gallons of water going down the drain.
The Bangalore Water Supply and Sewerage Board (BWSSB) has finally galvanised itself into activity and taken up a mega-pipeline replacement project.
Three key factors dictate the need for the project. Road-digging work for the Namma Metro project, road-widening projects as also the flyovers and underpasses being built by the BBMP and the BDA, which have damaged the pipelines over the years.
The BWSSB used to replace water and sanitary pipelines only on complaints or whenever there was a major damage to the supply lines.
For a city with 4,000 km of pipelines (water and sanitary) in core areas and nearly 3,000 km of pipelines in the newly added old CMC areas, the BWSSB has its hands full. The Board has proposed to replace at least 100 km of pipelines every year. Since 2008, it has already replaced 428 km of water pipelines at a cost of Rs 104.34 crore and 469 km of sanitary pipelines at a cost of Rs 80.19 crore.
The BWSSB is changing all water lines from old CI (cast iron) pipes to DI (ductile iron) pipes. For sanitary lines, SWG (stoneware glazed) pipelines are used. The Board is also using MDPE pipelines (Medium Density Polyethylene) and Galvanised Pipes (GA pipes) to replace the old lines.
A necessity
Nearly 36 per cent of the water pumped from various Cauvery projects is wasted due to leakage. Replacement of the water lines is then the only option. Recently, such pipelines were replaced on Hosur Road (near Nimhans) and Miller’s Road. These lines had been installed over 30 years ago. Heavy traffic on these stretches had taken a toll on the pipes, causing major leakages. After enduring traffic diversions for a few weeks, the residents around this area now get regular water supply.
T Venkataraju, engineer-in-chief, BWSSB, admits that such works will inconvenience the public for some time, but that has to be endured. “Citizens must understand that some of our pipelines are very old and need to be removed. The Board is now replacing feeder lines and sub-mains and subsequently house lines. But it is also the responsibility of citizens to change their house connection pipelines, which run from the road to their house taps, since leakage can happen at any point,” he explains.
According to BWSSB officials, the residents often complain about the mess in front of their houses whenever pipeline works are taken up. Procedure mandates that the engineers involved in the project wait for two days after relaying the lines to check if there is any leakage in the new lines. “The inspection of lines can be done only during supply time, but the residents do not wait till we complete our inspection. They just want the mess cleared,” laments an official.
Restoration costlier
Digging roads is a costly affair for the BWSSB, since the BBMP charges the Board more than it does the BSNL or Bescom. A BWSSB official explains that restoration work is 113 per cent more expensive than the actual pipe-laying work in the case of water distribution lines and 196 per cent more in the case of sewage lateral pipelines. The Board takes up restoration work only if it is part of their work order. However, in some places, the BWSSB pays the BBMP or the BDA to carry out the restoration work or to asphalt the roads.
To avoid digging the road, the BWSSB is also adopting the ‘trenchless technology’ wherever possible. This technology was used near the Silk Board junction, where the BWSSB was able to execute the work without disturbing the traffic. The same technology is to be adopted for the Cauvery IV stage II phase at the Kengeri railway station, where pipelines will have to be laid across the railway tracks.
Maps not available
Using Geographic Information System (GIS), the BWSSB had developed maps of all its water and sanitary pipelines in the City. These maps enable the Board’s engineers to track every pipeline and manhole. But despite this, the Board is handicapped without ‘altitude maps,’ the so-called ‘reduced levels’ 3D image measurements.
Explains a BWSSB official: “Maps on reduced levels would give us an idea about the level of the ground, and that in turn would enable us to pinpoint the place where leakage has occurred. These maps will also help in better maintenance of our pipelines. Although we don’t have them now, they could be created using Google Earth.”
Pipeline replacement
With the Namma Metro work gathering pace, the BWSSB had to replace pipes and shift utilities along different stretches. Since 2008, the Board has spent an estimated Rs. 24.59 crore on such works spread across all its six divisions. Utility lines along the entire Metro Reach-1 lane, with seven stations, have to be relaid.
The Trinity Circle junction was a mess till recently, with some of the sewage lines broken due to road-digging. It took nearly six months for the BWSSB to replace them.
Utility shifting
Every time the BBMP or the BDA takes up road-widening, underpass, flyover or stormwater drain work, the civic agency will have to shift its utilities to a safer place. The Cauvery junction underpass was one of the first projects, where the Board had to do this, triggering massive traffic blockages.
Subsequently, the BWSSB has taken up shifting of water lines at the BDA head office underpass, Cunningham Road Junction, Bellary Road ( for widening work), Golf Course Road, Palace Road, Race Course Road, Maharani College junction, Seshadri Road, Campbell Road, Nagarabhavi Main Road, Raj Bhavan Road, Nrupathunga Road, JP Nagar Ring Road, Miller’s Road, Ulsoor Main Road, Kalidas Road junction, BG Road, Yelahanka-Doddaballapura Main Road, Hosur Road Central Silk Board and Kadirenahalli Road junction.
Similar projects will be taken up in the future on the Madivala- Koramangala Road, Hosur Road-Sarjapur Road, Yelahanka-Doddaballapura Main Road, Palace Road, Yeshwantpur-Okalipura Road and on the Mysore Road-Sirsi Circle stretch.