CO 60 in Weld County
Damage Overview
Colorado Highway (CO) 60 in Weld County provides an important means of access for local agricultural activities and oil and gas development. The roadway provides access from the Town of Milliken to US 85 and I-25.
During the flooding, the Town of Milliken and portions of Johnstown were completely isolated due to flood damage to CO 60 and other nearby roads. Flood waters overtopped CO 60 for about half a mile in and west of Milliken.
The CO 60 bridge that spans the Little Thompson River experienced erosion and wash out of embankment at the abutments, loss of guardrail, and minor damage to the channel banks. Due to the large amount of debris that collected downstream on the adjacent railroad bridge, the embankments in between the two bridges were eroded as well.
The bridge that spans the South Platte River 3 miles east of Milliken was overtopped during the flood event. The roadway itself was also overtopped for approximately 1,000 feet on the north end of the bridge. The north abutment of the bridge was eroded and 10 feet of roadway pavement and embankment were washed out, exposing the bridge support piles. Large amounts of debris and sediment were deposited upstream and underneath the bridge.
Emergency (Temporary) Repairs
Temporary repairs were completed and the highway was reopened to traffic on September 21, 2013. At both locations, the roadway around the damaged abutments was repaired. The exposed piling and concrete abutment structures were filled and repaired. The south roadway embankment slopes and ditch were re-graded and backfilled, and guardrail was repaired or replaced.
Permanent (Long-Term) Repairs
Long-term repairs at the Little Thompson River will include removal and replacement of pavement overtopped by flood waters, repair of damaged utilities, removing and replacing temporary pavement installed during Emergency Repair and repairing and/or replacing damaged Right of Way fencing. Embankment slopes adjacent to the roadway that were disturbed during Emergency Repair will be re-vegetated with native grass seed and mulch. Erosion protection will be installed along the east bank of the Little Thompson River to tie into repairs made by the nearby railroad.
No permanent repairs will be made to the bridge crossing the South Platte River as the structure has been funded for replacement.
Estimated Timeline
- Estimated Design Start: Fall 2014
- Estimated Construction Start: Winter 2016-2017
Estimated Budget
- $10 million - $20 million (shared with project CO 257A)
Benefits
One of the goals in the repair process is to introduce certain betterments to roadway facilities that were damaged and make them more resilient to similar storm events in the future. Having analyzed the damage caused during the flood event, certain design elements will be incorporated in an effort to prevent or lessen the severe damage that significant flood events can cause.
At the Little Thompson River bridge site, protecting the roadway embankments on both sides of the highway east of the bridge will help prevent erosion failure during similar flood events.
