I-25 at Monument Creek Branch Flood Repairs

Project Facts

  • Cost: $2.4 million
  • Contractor: SEMA Construction
  • Timeline: April - October 2018
  • Location: Beneath I-25 from mile points 154.9 to 155
After: Southbound I-25

From mid-April to early October 2018, crews repaired culverts beneath I-25 at the Monument Creek Branch that were damaged during flooding in 2013 and 2015. The project area—between the Northgate and Interquest Parkway interchanges—addressed the following issues:

  • repaired concrete box culverts and wingwalls;
  • built concrete drop structures to prevent future failures;
  • armed channels with boulders, riprap and grouted riprap;
  • placed approximately 6,500 cubic yards of embankment material to restore the Monument Creek Branch channel and surrounding areas;
  • seeded disturbed areas;
  • made Prebbles Meadow Jumping Mouse habitate allowances; and
  • excavated approximately 1,550 cubic yards.


In 2013 and 2015, flooding overwhelmed the erosion-prevention material—aka, riprap—at this location, creating several new channels. The waters significantly degraded a 350-foot-wide median and the box culverts.

Flood water runoff also collected within a dip in southbound I-25, eroding a large part of the embankment on the west side of I-25. Erosion also undermined the integrity of guardrail.