Water cut blamed on staff inexperience

Ruapehu Bulletin, Volume 9, Issue 414, 26 November 1991, Page 3

Water cut blamed on staff inexperience

Sending staff who were unfamiliar with the Ohakune Water Supply system was the cause of last Thursday's extended shutdown of the water supply. The water was to be cut for an hour in the morning to allow staff to remove a water flow meter, installed in the main pipe near the bush exit of the pipe near Soldier's road. However the works team carrying out the task failed to open the sluice valve which releases the pressure on the pipes from the intake, Ruapehu mayor Garrick Workman said yesterday. "We regret any inconvenience caused by the delay in resuming the water supply," said Mr Workman. "What did happen should definitely

not have happened." He said the decision to send the team that carried out the work was made by senior staff who were normally very competent, "However they are also human. In my view, in hinds ight, they erred in proceeding without having someone more senior supervising the job, who knew the system better," he said. Those people were not available at the time, said Mr Workman. Mr Workman said the disruption to the supply occurred as a result of work carried out on the pipe in removing the flow meter, borrowed from the Rotorua District Council, that had been installed the week before, for the purposes of determining the capacity of the main from the intake to the town.

The meter had been installed by making a cut in the main in the vicinity of the pressure reducing valve where the main comes out of the bush at Soldier's Road. Restoration of the pipeline involved removal of the meter and reinstating the section of pipe with two "Gibualt" joints. The procedure was seen as being relatively straightfbrward, said Mr Workman, and was anticipated to take about 15-30 minutes, which it did. However when the team came to refit the section of pipe it was found to be too long because they had not reduced the pressure on the main by opening the sluice valve at the intake. This meant the pressure on the main moved it and closed the

gap. After shortening the section they managed to refit it and turn the water back on, but then they found water emerging from the ground on the pipeline route. The water had to be shut off again and the leak found, which was at a rubber ring joint in the asbestos concrete pipe, dislodged due to the movement of the main. This leak took some

time to be repaired, with the water being turned on at 6.30pm, said Mr Workman. He said there was no permanent damage caused to the main. The mayor has been advised that, failing natural disasters, there should be no further disruption to the water supply until work is carried out on commissioning the new water treatment system.