Water flowing in with full pressure from the much-awaited Melamchi drinking water project may see taps running soon; but it could also cause damaging pipe-bursts and high volume of leakages
Illustration: Ratna Sagar Shrestha/THT
Reasons vary on why such accidents could happen. Some areas that still have old pipes run that risk.
The way even new pipes have been laid down and the topography of the
Valley could also become reasons. The Ministry of Water Supply has even
formed a taskforce whose mandate is to commission the pipelines after
testing so that risk of leakages and bursts can be reduced.During the testing phase, there was a joint slip that led to spewing up of a huge amount of water out of the pipes in Chabahil area on November 1. Bhim Upadhyaya, former secretary, Ministry of Water and Sanitation, who is now the coordinator of the taskforce, says it could become a major issue. “If this happens during the operation phase when pipes are fully pressurised, it may create a problem with massive flow.”
Knowledgeable sources say about 35 per cent pipes used in the Melamchi project are old. That is why, they add, there is a risk of leakage, water burst, flooding of roads and even accidents when the water flows in full force. However, even the new pipes that are yet to be installed properly or where poor quality materials have been used are prone to burst. Water fountains from such bursts could be up to 10 metres high or more and they could damage infrastructure, property and passing vehicles and even injure people.
Government officials, however, say the risk of pipeline bursts is very low, but there could be high volume of leakage. They argue that Ductile Iron (DI) Pipe and High Density Polyethylene Pipes (HDPP) have been used in the construction of distribution pipeline networks and they can withstand pressure up to 250 metres but the pressure from Melamchi is only 130 metres. The total length of the existing drinking water pipeline in Kathmandu valley is 1,300 kms and 1,000 kilometres of that has been replaced.
Many sections of the pipe networks were laid during nighttime without adequate lighting and that, experts say, could have meant that some of them may not have been installed properly.
Add to that the uneven surfaces of the Valley that make pipes more vulnerable to disjoining and leaks. If installations in such locations have not been done properly, the risks of bursts grow. Of course, Kathmandu valley’s age-old drinking water pipes have always been notoriously leaky — around 40 per cent of the supplied water leaks. But because the water running in the pipes were relatively less, the leakages were not dangerous. Once the multi-million-dollar Melamchi project kicks off, the flow will rise by at least four times, which means bursts could be damaging.
The Valley will receive 170 million litres of water a day under the scheme while now the supply is nearly half of that during dry season. To cope with the spiralling demand, projected to reach 530 million litres a day by 2021, Melamchi project will add waters from Yangri and Larke rivers from Sindhupalchok. And that could mean more pressure to the pipes.
General Manager of Kathmandu Upatyaka Khanepani Limited (KUKL), Mahesh Bhattarai, however, agrees that there is a high chance of leakage of water after implementation of the Melamchi Drinking water project. “These existing system pipelines are vulnerable to leakages due to increase in the volume of water supply.”
The KUKL has formed its Project implementation Directorate (PID) to look after loss or damage in the new pipelines. This unit operates with the assistance from the Asian
Development Bank (ADB), a major donor of the Melamchi project. The bank’s officials say PID will go neighbourhood by neighbourhood to test the
system.
Once they are assured that the leaks are minimal then they will switch the old networks to the new networks. And PID officials assure that they are equipped with patching tools and machines and that they are prepared for burst-related events.
Despite such assurances, there is a reason to worry: Even after significant increase in water supply volumes once Melamchi project is commissioned, monitoring and control of flows will be done manually for now. A computerised system, called the Supervisory Control and Data Acquisition (SCADA), is in the process of procurement and will be installed only after two and a half years once the project has been completed. That means it will not happen before 2020. Till then monitoring and controlling will have to be done manually which may become very challenging when the water flow increases by four folds.
KUKL officials claim that they are capable of handling the situation even if that will have to be done manually for now. But there will be few takers of that given the mismanagement of sewage and drinking water infrastructure in the past. Only recently, a cyclist in Kirtipur lost his life after falling into a manhole, which KUKL has been accused of keeping intermittently open for months.
A version of this article appears in print on December 12, 2018 of The Himalayan Times.
