Sunday, 29 Jan 2023

I-70 flood results in $45,000 fine, new pump system safeguards

The lead contractor on the Central 70 project will pay a $45,000 fine for a pump failure that caused severe flooding and says in a newly released report that it has added safeguards to ensure the system works properly during future storms.

Nearly a dozen motorists were stranded and needed rescue when a burst of heavy evening rainfall hit Denver on Aug. 7, flooding both sides of Interstate 70 through a construction zone near York Street. That is in a section of the highway that was depressed below ground level, replacing a viaduct, as part of the $1.3 billion highway project.

Major construction is now done on the project, with final work expected to wrap up next year. By August, the flood-control system was in place and functional. Kiewit Construction’s corrective-action report, released Tuesday, makes clear that human error was the reason that neither the main pumps nor a backup system kicked on.

“Our investigation of the August malfunction determined that computer settings that manage the pumps were set incorrectly,” a company statement says. “That has been corrected and the main pump system and the backup system have been tested frequently and have effectively managed rainfall since the August event.

“We continue to monitor the system to ensure its continued reliability.”

The fine is based on contractual violations and was set based on Kiewit-Meridiam Partners’ overarching public-private partnership agreement with the Colorado Department of Transportation. The team designed, financed and built the 10-mile highway project, which added express toll lanes between I-25 and Chambers Road and includes a new cover park over the highway in Denver’s Elyria-Swansea. It also will maintain the highway stretch for three decades.

While the flooding incident won’t cost Kiewit much, it did give the project team a black eye.

“We are embarrassed by this event, especially in the light of the many current successes,” Kiewit executive vice president Scott Cassels wrote in an email to a CDOT official the morning after the incident, pledging to investigate what went wrong.

The pump failure spotlighted a key vulnerability before a worse disaster happened.

In the 1.8-mile depressed section in northeast Denver, the drainage system is a vital feature since the highway sits in a trench dug down nearly to the water table. It includes 6-foot-diameter pipes and eight detention ponds, along with automatic pumps to quickly clear any pooling water.

“I’m not going to stand there and say that (the flooding) was a good thing, but we did learn a lot, and we’ve now put in safeguards to make sure it doesn’t happen again,” CDOT project director Bob Hays said in an interview last week. “So to me, that is a good outcome of a pretty bad day.”

The fine will be deducted by CDOT from the $13.6 million payment it owes Kiewit early next year following a mid-February deadline to reach substantial completion on the project. Earlier delays pushed that milestone back from March 22 of this year in the original project schedule.

Meeting the February deadline on time now depends on receiving federal certification of a flood map revision for an overflow channel, according to Kiewit’s latest monthly project report.

Read Kiewit-Meridiam Partners’ corrective-action report:

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