The sinkhole along Anzac Pde that has opened up and now threatens telco cables.
The sinkhole along Anzac Pde that has opened up and now threatens telco cables.
A small sinkhole next to the Whanganui City Bridge has grown and is now threatening telecommunications wiring.
A reader called the Chronicle, concerned about the hole, which she says has been getting gradually larger. It is part of a washout caused during flooding in June last year.
The riverside walkwayand edges of the road - which is part of State Highway 4 - were damaged when a part of the footpath near the Anzac Pde-Portal St intersection collapsed. Then, at the end of July, another section slumped, taking out the footpath from Taylor St to the City Bridge.
Repairs are expected to start soon.
Ross l'Anson, NZ Transport Agency highway manager, confirmed to the Chronicle late last year that design work should be completed in December, and that contractors should be on the job early in this year.
At the time NZTA said engineering assessments after that second slump showed up a bigger - and more costly - problem than first thought. The final sum could reach $5 million.
"We had identified potential issues with erosion of the river bank below the water level so we've been working with a geotechnical expert to come up with the right option for this area which has complex hydrology and river dynamics," Mr l'Anson said.
He said several options had been considered but, based on advice from a geotechnical expert, NZTA was now taking the best option through to a detailed design stage and that was expected to have been completed last month.
"Having detailed designs and construction drawings will enable the contractor to start their preparations, including sourcing materials and subcontractors and we expect the contractors to start on site early 2017.
"It's important that we get the right design to repair this section of Anzac Pde and we appreciate the ongoing patience of the Whanganui community," he said.
NZTA will foot the bill for the project because it's part of the state highway network. Mr l'Anson said they were considering using sheet piling, which uses interlocking sheets of steel to form a retaining wall. This retaining wall will allow contractors to clear the site of water, before building a permanent retaining structure.
