State project officials received $1.3 billion for the rebuild of Interstate 70 through northeast Denver and now say they will investigate severe flooding in an under-construction section.
According to The Denver Post, this flooding resulted in the rescue of motorists. Heavy rain fell in a short amount of time and I-70 was closed for hours with the highway reopening at about 10 p.m August 7th. Since the flooding, project officials aim to investigate what happened to overload the system.
According to The Denver Post, the flooding occurred in a 1.8-mile recessed, mostly open air section built below ground level between Brighton and Colorado boulevards to replace an old viaduct, which is nearing the completion of major construction. According to state officials, this project is a major portion of the 10-mile Central 70 project that requires a stormwater drainage system. This includes 6-foot-diameter pipes and eight detention ponds, but the system is not yet complete, Sellers.
“Safety is always CDOT’s number one priority, (and) we will do what it takes to help prevent something like this from happening again in the future,” said Stacia Sellers, the spokeswoman for the Colorado Department of Transportation’s Central 70 project office, in an email, reported The Denver Post.
Denver Fire Department firefighters rescued 11 people from their waterlogged or stranded vehicles on the highway near the westside of York Street.
“The Central 70 Project is going to conduct a thorough investigation to determine what exactly caused the flooding this evening,” Sellers wrote in the email, reported The Denver Post. “As an active construction project, if there are any system failures, we are able to go in and remediate any issues that occurred during this event and have everything in order before the project is officially complete.
He added that, "however, without conducting the investigation, we do not know if there was a system failure.”
Once complete, the drainage system is designed to channel water off the freeway surface during a 100-year flooding event. A similar drainage system was built for a recessed section of Interstate 25 in Denver. Officials are unsure if the August 7th rainfall over I-70 neared the 100-year event threshold.
Lead contractor, Kiewit Construction, sent workers to pump water to offset the lack of a full drainage system, added The Denver Post. The recessed highway zone eastbound side’s traffic now is in its final configuration and the westbound side remains in a temporary setup with plans to remove remaining concrete barriers in coming weeks.