While installing a new 8-inch water main in Main Street, contractors for the City of Vancouver today uncovered an old cistern, about 16 feet in diameter and 12 feet deep, used an estimated 75-100 years ago to collect stormwater runoff for fire suppression.
About 90 cubic yards of stabilizing material, just over a dozen loads of controlled density fill – a type of concrete – is being brought in to fill up the deep hole beneath the street. The stabilizing fix is expected to be completed quickly, so work on the water main installation can resume.
“When working underground in the oldest areas of a city, you can encounter the unexpected,” said Dan Swensen, Vancouver Public Works Construction and Engineering Manager. “Over the years, we’ve discovered old trolley lines, wood-stave water lines and wooden telephone conduit buried deep beneath the streets, along with other abandoned infrastructure.”
Work on the installation of the new 8-inch water main line in Main Street, between 12th and 15th streets, began March 24. Integrity Excavating of Battle Ground is the City’s contractor and lowest responsive bidder for this project. The new, larger-diameter line will provide improved water distribution and fire flows in the area, and resolve maintenance issues and service interruptions related to the old, aging 4-inch-diameter main line, also about 100 years old.
Traffic disruptions are being minimized to the extent possible for this downtown Vancouver project. However, drivers are asked to be prepared for delays and watch for traffic changes.
The water main replacement project is anticipated to be completed by the end of April.