CO 257 in Milliken

Damage Overview

CO 257 is a primary commuter access route between Greeley and the Milliken/Johnstown area, connecting CO 60 in Milliken and US 34 about 10 miles west of Greeley. During the flood event, floodwaters from the Little Thompson River overtopped the roadway in Milliken from the intersection with CO 60 north to where CO 257 crosses the main channel of the river.

The bridge there sustained significant damage to its abutments, and part of the roadway was washed out.  Farther north, where CO 257 crosses the Big Thompson River, similar damage occurred to the bridge there as more than half-of-a-mile of roadway was overtopped.

Emergency (Temporary) Repairs

Temporary repairs were completed and the highway was reopened to traffic on September 29, 2013. At both locations, the roadway around the damaged abutments was repaired. The exposed piling and concrete abutment structures were filled and repaired. The roadway embankments were repaired, and damaged guardrail sections were reset. At the Little Thompson site the east roadway embankment and ditch were re-graded and repaired.

Permanent (Long-Term) Repairs

Long-term repairs 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. Ground adjacent to the roadway that was disturbed during Emergency Repair will be re-vegetated with native grass seed and mulch.

Estimated Timeline

• Estimated Design Start: Fall 2014
• Estimated Construction Start: Winter 2015-2016

Estimated Budget

• $10 million - $20 million (shared with project CO 60B)

Benefits

One of the goals in the repair process is to introduce certain betterments (improvements beyond bringing the road to standard) to roadway facilities that were damaged and make them more resilient to similar storm events in the future.  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 the east side of the highway will help prevent erosion failure during similar flood events.