Vital supply to metro cut off in Kirkwood canal collapse
In the wake of a further blow to Nelson Mandela Bay’s precarious water predicament, engineers and construction teams will be scrambling to repair a collapsed water canal in the Sundays River Valley within the next few days – or taps in parts of the metro could run dry.
The canal, running through a Kirkwood farm, was destroyed in a landslide on Wednesday, cutting off the main water supply to the Nooitgedacht water treatment facility.
Thousands of litres of clean water went to waste before the supply was closed off.
Now teams from the Department of Water and Sanitation, in cooperation with the Lower Sundays River Water User Association and the Nelson Mandela Bay Municipality, are working on a temporary solution to restore the water supply.
Department spokesman Sputnik Ratau said their officials had been on site shortly after the landslide occurred and were assessing the situation.
“We are still determining the extent of this disaster and can waste no time in restoring the water supply,” he said.
“This canal is an integral part of the Nelson Mandela Bay water supply, and also affects the Sundays River Valley directly.
“It is difficult to put a timeframe on the repairs as assessments and costing are still being done.
“But we have no choice but to get this waterline up and running as soon as possible.”
The canal is fed by the Sundays River and leads water to the Scheepersvlakte Dam, and then to the Nooitgedacht facility near Addo.
From there, it is pumped to the Grassridge Reservoir that supplies areas like Coega Kop, Colchester, Motherwell, Chatty, Bethelsdorp, Bloemendal, Despatch and parts of Uitenhage.
“Soil naturally shifts from time to time. This canal was built around 1986 and unfortunately these things happen,” Ratau said.
An on-site official from the department, who declined to be named, said the landslide could also have been brought on by small leaks in the canal wall that, over time, softened the clay soil, causing it to shift.
“However, it does not really matter what caused the slide,” he said.
“What we need to do now is figure out how we are going to relay the water temporarily and restore the supply.
“The permanent repairs will come later because it won’t be a quick fix.”
Nelson Mandela Bay mayoral committee member in charge of infrastructure and engineering Annette Lovemore said the Scheepersvlakte Dam held enough water to supply the affected areas for seven days when full. However, under the current conditions it held enough water for only four days.
“The significance of this incident is that 30% of the water supply to Nelson Mandela Bay is at risk,” she said.
“The damage is significant and with only four days’ storage left in the Scheepersvlakte Dam it is envisaged that from Monday the supply to the eastern and northern parts of the metro will be affected.”
Ratau said it should not take more than a week to find a temporary fix, but Lovemore said that could leave the affected areas without water for three of four days.
The municipality plans to relay water from other pipelines to help mitigate the problems. Water tankers will also be deployed.
“It is therefore imperative that water usage in the metro be cut to the bare minimum. Non-essential use, for example washing cars, must be stopped,” Lovemore said.
Sundays River Citrus Company managing director Hannes de Waal said it was still too early to tell whether the fruit production operation in the valley would be affected.
Lower Sundays River Water User Association chief executive Harms du Plessis said only once the water supply was restored would they be able to determine how this disruption would affect irrigation.
Hannes Joubert, the owner of the farm where the canal collapsed, said they were still assessing the full extent of the damage to their orchards, but were relieved that no one had been hurt in the incident.
“Some workers phoned me and told me about the landslide around 4pm [on Wednesday],” he said.
Joubert, who also runs Habata Fruit, one of the largest fruit producers and exporters in the valley, said 26ha of orchards where they grow lemon and orange variants were affected and the chances were that they would not be able to harvest from this section.
“Besides the trees that were buried under the mudslide, we have to look at the effect the floodwater, mud and silt will have on the remaining trees,” he said.
“Fruit could drop from the trees as well, and if we cannot get to it on time, due to the flooding, we cannot use it for export or local markets.”
Joubert said the financial implications still had to be determined.
However, he estimated that each hectare could deliver 40 tons of fruit, equating to a potential loss of 1 040 tons of fruit.
Once the cleanup is complete, he will have to determine how many trees can be salvaged and how many of the orchards will have to be started from scratch.
Operations to clean up the orchards and roads leading to sections of the farm cut off by the landslide are already under way.
Joubert said their first priority was to regain access to all parts of the farm.
“That way we can at least continue working on the sections that are still operational,” he said.