In recent months Wellawatte South where I live has had water supply failures very often. My complaints to the National Water Supply and Drainage Board have brought no permanent solution, but water bowsers were offered. There is in fact a serious situation arising. The UDA is best equipped to initiate and monitor action by the National Water Supply and Drainage Board (NWSDB) to avoid such a crisis.
Only some consumers are aware of the water interruption. Two categories of consumers know the water failure immediately. Those living in buildings with no overhead tanks who depend solely on the supply from the street and those in two floor buildings that have the supply on the second floor from an overhead tank and the ground floor direct from the street water.
Those with overhead tanks up to about 25 ft above ground who depend on them filling at night will have no water when the tank runs dry – may be hours or a day later after a water cut depending on tank capacity and daily usage. The last to be affected are those with an underground tank (sump ) from which water is pumped up to overhead tanks, when both sump and tank are empty. During this staggered impact, (quite a contrast to electricity failure ) the water supply often re-starts and as long as some water comes from taps the consumer grudgingly accepts it. All this has led to an attitude amongst us, that everything is all right with the water system in Colombo city.
More than enough water is available at the source, with the Kaluganga water supply scheme now supplementing the Kelani river Ambatale intake. This availability will in future increase when the huge second filtration plant on the Kelani comes on-stream. By then the age-old problem of salt water coming to Ambatale during certain months would also be solved.
The problem lies elsewhere-- small size and very old iron pipes
The iron water pipes along most roads are over 70 years old. In the late 1970s the large diameter pipes (about nine inches and over ) from which connections are given to the smaller diameter pipes, were lined with cement by a foreign-funded project. Nothing was done by NWSDB for the small diameter pipes which connect to the consumers. Such small diameter iron pipes are so old and corroded that they are beyond repair. Water leaks through them and is now the main reason for “non revenue” water for the NWSDB though this was blamed on wastage at street standpipes and taps in ‘wattes’. This has now been stopped, but the non revenue water still continues because of leaking pipes.
These leaking pipes are also a serious health hazard. When water pressure inside them decreases during hours of high consumption, the water outside goes inside the pipes. Outside water would come from polluted ground especially as the glazed clay sewerage lines are also very old and often run close to the water pipe lines. The water pipes also pass garbage dumps and marshes on the roadsides. Therefore while at the filtration plants’ water conforms to WHO standards, it certainly would not at all times, conform at the tap of a consumer.
There is black stinking sediment deposited inside the pipes thus reducing their carrying capacity by as much as 50 % and over. This was seen by all when some 10 years ago the CMC was pressurised to clean the pipes down the lane where I live. The pipes break when cleaning them out and therefore no attempt is made to clean them, either by the CMC in past years or now by the NWSDB.
With many high-rise apartment blocks coming up, the consumers per given area have increased by as much as 12 times. Yet the water lines connected to the apartments are often from the closest water line that served the single home that was in the premises before the apartments were built.
Apartment buildings have huge underground sumps from which the water is pumped up into overhead tanks. So long as the sump gets enough water for the consumption until the next water failure, the apartment dwellers have adequate water. Gradually these sumps will get less water and when the supply is not enough for the next day and the overhead tank is empty, apartments will have no water.
This situation is not far away. Some apartment blocks have dug tube wells to supplement supplies.
Apart from the corroded small diameter pipes, the valves also need replacement. They control the amount of water that is sent down different areas. They are underground and the tap by/in the road is opened or closed by NWSDB employees manually with a lever. These valves are as old as the pipes. They do not operate properly and therefore the control of water flow is adversely affected. Some years ago NWSDB marked their locations with pegs driven to the ground with the letters SV but we have seen no site visits.
There is an expected standard water pressure in a pipe line. Our water pressure at most times is well below this. NWSDB may have the technical equipment to record continuous water pressure like what the CEB has for electricity. If they do, they have not used it so far. Recently a group of eight workers went down our lane asking “do you get water? “. Surely the NWSDB can do better.
Consumers have taps at various heights; toilet cistern at 3 ft, wash basin at 4 ft, pantry swan neck taps a little higher, showers at 7 ft. and overhead tank at 23 ft At least enlist the support of say one household in each lane, to write on a pre-printed sheet the day and times at which there is adequate water at each of these levels.
Fortunately for Colombo the re-vitalised UDA has stepped in. A programme of replacing the small diameter pipes must be started simultaneously in several Wards. NWSDB engineers should be required to prepare a comprehensive Project Report within a given time frame. There would be several who have much experience as Project Directors and would be familiar with this task. New pipes should be laid alongside the old ones and the consumer connections transferred from the old to the new pipes. This would minimize the water supply interruptions.
Our engineers would be able to handle it with local materials and with no further overseas training. It should be outsourced as in- house work will suffer very long delays, due to absenteeism, lack of coordination to have all materials and equipment at each site at the required time, low productivity and the absence of professional level Job Costing so in house costs often exceeding the sums paid for outsourced work, will remain hidden. The labour supply for this type of work is limited as hundreds of thousands of men prefer to be tri shaw drivers. Perhaps an attractive daily pay may persuade an adequate number of them to change over.
It would be ideal if the outsourcing is to the armed forces. They would do a great job.
(The writer was a Deputy General Manager of the NWSDB)