Northbound Interstate 25 between Interstate 70 and 58th Avenue closed this afternoon after five-foot-diameter water main burst under the highway near 58th Avenue.
At one point this evening, northbound traffic was backed-up south all the way down I-25 to University Boulevard.
Rush-hour traffic is being diverted over to Washington Street to the east and Federal Boulevard to the west. Some traffic is using the two-lane HOV lanes without being charged a fee.
No one was injured when the pipe burst around 3 p.m. but one nearby business suffered some damage.
More than 2 million gallons of water gushed out, causing the highway roadbed to develop a sink hole estimated at 40 feet by 40 feet and as much as 16 feet deep.
CDOT spokeswoman Stacy Stegman said that the interstate would definitely be closed overnight.
“This is a big one,” she said.
She said the sinkhole was twice as big as one that closed Interstate 70 near Vail for three days in 2003.
Brian Good, director of operations and maintenance for Denver Water, said at an evening press conference “our goal is to have the repairs completed by rush hour (Friday).”
Good said the break was caused by overpressurization of the line after a pump failed and shut down in an emergency situation.
Denver Water said no one should lose their water service, although some may experience low water pressure. If there is an outage, customers should call Denver Water at (303) 628-6000.
The same pipe broke in 1997 about 100 yards to the west on the other side of the highway, causing flooding and significant damage. Clean up and repairs took three days.
Since then, Good said, the line has been inspected four times and more than a mile of it has been replaced.
The conduit was installed in 1978. Good said that age was not a factor in the break, since the line can last up to 100 years.
Good said the concrete transmission line will be repaired with steel.
