Dive Brief:

• Kiewit Meridiam Partners found computer errors were responsible in part for flooding a low-lying portion of I-70 that nearly submerged cars as heavy rain slammed Denver this summer.
• The contractors were tapped to design, build and maintain the 10-mile, $1.2 billion Central 70 project that runs through northeast Denver. Drainage systems did not perform as planned on the newly opened roadway and the pumps did not kick on automatically like they were supposed to amid an Aug. 7 flash flood. Firefighters had to rescue 11 people from vehicles, according to the Denver Post, but no one was injured. 
• Kiewit is looking into the incident, and found technical errors were responsible for the pump problem. “Our investigation of the August malfunction determined that computer settings that manage the pumps were set incorrectly,” said Matt Sanman, spokesperson for Kiewit. “Although the investigation is still being finalized, 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.”

Dive Insight:

Colorado DOT is also investigating, and is trying to figure out how much to fine the contractors involved. In August, the agency said the amount would be at least tens of thousands of dollars.

The Central 70 project, which began in 2018, was developed to address safety concerns on the aging road and meet growing transportation demand. It entails reconstructing I-70 between Brighton Boulevard and I-270 in northeast Denver, removing a 57-year-old viaduct, lowering the highway and installing express lanes, seven miles of sidewalks and a bike route. To cap it off, a 4-acre park is being built over the interstate.

Progress has continued since the incident, which did not impact the timeline, according to Colorado DOT spokesperson Stacia Sellers. The express lanes opened on Aug. 31, marking the last major milestone on the project. Remaining work on the park portion will extend through 2023.

The day after the flood, Kiewit Meridiam Partners and Colorado DOT pointed to issues with the drainage system, which was supposed to withstand a 100-year storm event but was not yet complete. Besides the issue with the pumps, Colorado DOT said incomplete pavement may have played a role.

In addition, Colorado DOT said it is investigating several “non-conformance events” in connection with the incident. A NCE occurs anytime that the developer does not meet the performance requirement, Sellers said via email. Kiewit Meridiam has a set amount of time to remedy the issue and there are penalties for noncompliance.  

According to Sellers, three requirements were not met on the project at the time of the incident:

• Each element of the drainage system is maintained to ensure that it functions correctly.
• Subsurface drainage and pumping systems are fully operational and clear of debris.
• Command, control and monitoring system provides the intended function of control, monitoring, communication and visual display of all connected systems including integration with other systems. 

The construction industry is particularly vulnerable to the effects of climate change, and the I-70 incident is just one example of how jobsites are increasingly being hit by extreme weather. Heatwaves and intense storms can translate to equipment and jobsite damage, delays, lawsuits and other costly impacts. 

Besides a fine, no other action will be taken against the contractors for the flooding, according to Sellers. A silver lining of the incident is that it highlighted a key vulnerability before the project was finished.

“While the situation is unfortunate, having this happen while construction is still underway helped us identify additional improvements and safeguards that can be made to ensure this event does not happen again,” Sellers said.