More than 80 per cent of Christchurch’s water and sewer systems were severely damaged by the devastating earthquakes in September 2010 and February 2011. In response, Sydney Water co-ordinated a taskforce with six Australian pipeline rehabilitation companies to provide personnel and equipment to the disaster-affected areas. Members of Water Infrastructure Group (WIG) were part of the team helping to restore the city’s sewrage system.

WIG redeployed resources so that a team of seven skilled operators and three trucks, equipped for CCTV camera and water jetting work, could travel to New Zealand.

Kevin Kane, Water Infrastructure Group’s Project Manager in Christchurch, said that when the taskforce arrived in March, approximately half of Christchurch’s 1,700 km sewerage network was not functioning.

“As a result of liquefaction, many of the sewer pipes have been left full of sand that is hardening. We’re using 2,000 psi water jetting hoses to soften the sand so that it can be removed,” he said.

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“Our hoses are fed into manholes and can push through the pipes for up to 200 m. When the hydraulic reel on our trucks wind the hose back to the manhole, the sand and water follows the hose back toward the manhole. We can then use suction hoses to pump the sand into trucks for removal.”

Mr Kane said that by Easter it was estimated that 65 per cent of the network was working.

“There have been aftershocks and it is frustrating to arrive at a section of pipe we’ve successfully cleared to find that all our good work has been undone by further liquefaction,” he said.

“This means that it will take longer to get the sewerage network fully functioning but I’m confident we will get there and people in Christchurch will be able to get back to a more normal way of life.

“The effects of the earthquake have been severe and the dusty conditions mean that we have to do a lot of maintenance on our equipment but we are making progress.”

But Mr Kane said “I think I can speak for the whole team when I say that although the conditions are challenging it’s been very rewarding to be part of this massive clean-up operation.”

Once the sewer pipe is clear of sand, the team will be able to send CCTV cameras down the pipe to check for structural damage and provide help with any further work required.

“We are helping to get the system working again as well as providing information collected with our CCTV equipment and advice for the next rehabilitation phase to fully reinstate the sewerage system,” Mr Kane said. “This will be a huge task and could take years to complete.”