Contracted crews and workers are preparing to fix the sinkhole on Winnipeg Street.

Workers will be installing a 9 m by 4.8 m concrete chamber to replace a failed section of sewer pipe, which has caused several sinkholes at that location over the years.

For the past two weeks, crews have been constructing the chamber on site. This chamber will be able to withstand the pressure of large storm events similar to the one in June.

Photo Credit: City of Prince George

During earlier work, it was discovered that over 8 m of pipe was completely deteriorated at the sinkhole. The City believes the deterioration was caused by turbulence from the discharge of stormwater from the Carney Street sewer system that enters the pipe at the location of the failed pipe.

“The pre-cast concrete chamber is designed by engineers to withstand the turbulent forces of large amounts of water flowing through it during storm events,” says Josh Kelly, Supervisor of Energy, Environment, and Sustainability. “Now that the chamber has set to the required strength, a crane is being used to install each of the four 23,000 kilogram sections to replace the deteriorated portion of the metal pipe.”

After installation, the water main at the site will need to be replaced, traffic signal and streetlight poles must be reinstated and backfilling will be done to restore the road base.

The City estimates that the entire intersection will reopen to traffic by mid to late October.