Crews Complete Flood Repairs Under I-25 Between Northgate & Interquest Parkway

SOUTHEAST COLORADO—CDOT has completed culvert repairs at the Monument Creek Branch under I-25 between the Northgate and Interquest Parkway interchanges (from mile points 154.9 to MP 155.0). This work was necessary following storm damage in 2013 and 2015.

"The flood work was completed with minimal impacts to traffic. Work was in the median between southbound and northbound I-25 and west of southbound I-25," said CDOT Project Engineer Austin Gilbert. "The project finished on budget and completed in under six months."

Completed Work

• concrete box culvert and wingwall repairs
• construction of concrete drop structures to prevent future failures
• channel armoring with boulders, riprap and grouted riprap
• placement of embankment material to restore the Monument Creek Branch channel and surrounding areas
• seeding of disturbed areas
• Prebbles Meadow Jumping Mouse habitat allowances
• placement of approximately 6,500 cubic yards of embankment material
• Approximately 1,550 cubic yards of structure excavation

Project Background

The soil throughout this area was highly susceptible to erosion. Storm flooding in 2013 and 2015 overwhelmed existing riprap in the channel and created several new channels. The channel in the 350-foot-wide median between the structures was significantly degraded and the box culverts were significantly scoured. The runoff collected within the roadway sag of the southbound I-25 lanes, overtopped the asphalt curb, and eroded a large area of the west side roadway embankment of I-25.