As the first raindrops marked a very wet weekend, residents were left without water and electricity and municipal maintenance teams were pressured into long hours, harsh weather conditions and one problem following right on the heels of another.
“The past weekend reminded me of periods last year and painfully illustrated that we still have a long road ahead of us, before our infrastructural base will be stable and less fault prone. This weekend we were confronted with numerous water and electricity problems, and this affected specific areas more than others,” said a tired administrator, Mr Theo van Vuuren, who kept residents updated on the problems on Facebook.
Rain and old cracked cables is not a good combination.
As equipment, and especially cables, are old cracks may develop which absorb moisture and lead to blow ups. Considering that the normal lifespan of a cable is 20 years, some of the electrical cables are approaching 50 years.
The cost per meter on a cable, like those that are constantly blowing, is R1 500. To overhaul the electrical system is estimated to be in access of R400-million. This forces the municipality to operate in crisis management mode.
“The argument that these cables should be replaced is very relevant, but normally a maintenance and replacement programme should annually have formed part of the municipality’s activities. For many years it didn’t. We are systematically, as funds allow, replacing cables, but do not have the funding for any large scale replacement programme at this stage,” Van Vuuren said.
Apart from the old dilapidated infrastructure, vandalism and cable theft also add to the frustration.
“When doors have been broken open, this also affects the water resistance of a facility such as a substation. Where illegal connections are made, these connections are often not well water proofed and can also lead to blow ups. Due to the magnitude of these problems, it is not possible for the municipality to constantly search and repair these issues,” Van Vuuren said.
Often cables are damaged by other entities doing repairs on their networks. In many cases the damage is minor and often not visible, but these points become brittle and in the rainy season water may penetrate.
On Friday, November 14 residents were left in the dark when a 22kV cable between Driehoek and Malherbe substations failed. Fault finding became increasingly difficult as a maintenance team made their way on the 8km cable that runs through a densely populated area, mining area and bushveld.
The maintenance team on standby only had skeleton staff available and did the repairs assisted by an external contractor. Inclement weather made it difficult for the teams to work, and it was eventually found that the cable had blown on a section previously damaged by Telkom contractors on the corner of OR Tambo and Steenkamp streets during the laying of optic fibre cables.
The continuous rain caused the cable to absorb moisture and thereby causing the fault. The areas that were affected were Klipfontein, Del Judor and Extensions 5, 8, 12, 16, 18 and 41.
Power was restored at 20:00 on Saturday, November 15.
Half an hour later Extensions 12, 16, 18 and 41 again had no electricity when a mini-substation transformer in Steve Bantu Biko Street blew and caught alight on the high voltage side.
This caused extensive damage to the high voltage switchgear and cables. The explosion was due to the presence of moisture with the continuous rain that has currently been experienced in the area.
Only at 16:30 the next day was power restored.
While all that drama was unfolding, a feeder line absorbed moisture and caused the power supply to Ben Fleur and Reyno Ridge to trip on Saturday at about 18:30.
This was partially restored the same evening; however an 11kV feeder line remained off due to a cable absorbing moisture which supplied a section of Ben Fleur and Bankenveld. This was restored 16 hours later.
But there was no time for the maintenance team to take a break when power was restored to Die Heuwel Substation and it was discovered that the Amsterdam feeder line had an earth fault indication due to a faulty underground cable.
The power tripped at 02:00 due to a blow up of a feeder cable in Amsterdam Street which supplies Die Heuwel and parts of Model Park.
The maintenance team was assisted by an external service provider to identify, excavate and repair the power supply which was restored at around 15:30 to the affected consumers.
However commercial customers complained of reverse rotations and the supply had to be switched off to rectify the matter and was eventually restored around 18:00.
The cable absorbed moisture and blew on a worn out section of cable. The customers that were affected by the cable fault were in Amsterdam Street and surroundings, Saveways Crescent, part of Model Park and Fransville. Power was also out most of the day in Vosman, at the KG Mall area and at Hlalanikahle 1 and 3. These problems had to do with breaker overloads and minor burns. These were repaired.
Sunday had a similar pattern.
At 12:30 an underground line feeder cable blew up between Point B Substation and Montgomery Street, causing a power outage to residents around Witbank Extension 5 and Point B. The electrical maintenance team utilised a ring-feed supply to restore power to the affected areas.
“Reasons for the blow up are still unknown and the maintenance team will perform the repairs during the course of the week,” Van Vuuren said.
Power was also out for another hour in the area and the fault was found to be a mini substation transformer which had tripped and the maintenance team restored the power supply after performing all the relevant tests to determine if there was any fault.
“Klarinet Ext 5 also experienced an outage due to overload at the substations. So did Hlalanikahle 1 and 3,” Van Vuuren sketched the weekend’s power outages.
Although many water outages were in the same areas as power outages, they were unrelated.
The water outages in all cases were as a result of pipe bursts. The bursts occur as old pipes (similar to electrical cables) develop weak points over time, which at any given time may result in a crack and eventually a burst.
To overhaul the total water system will cost the municipality R1.1-illion and they hope to achieve this over a five-year period.
“There is a programme with Rand Water on the go to systematically replace especially the old asbestos pipes but it will take a number of years to complete. In addition, many of the pipes do not have air valves and when air is trapped in the pipe, this will lead to a burst. We are in the process of installing air valves in the most problematic areas and have already done so in many areas,” said Van Vuuren.
He said the team attended nine pipe bursts in Blanchville alone last weekend.
All of these affected the same areas, as the main supply had to be closed to allow repairs. In Clewer there were not less than four pipe bursts in different streets last weekend,
“A complicating factor is that during rainy weather, like over the weekend, work conditions become very difficult especially with machinery slipping in the mud and visibility being impaired, leading to longer than normal repair times,” he explained.
