CO 119 Boulder Canyon

Project completed

Damage Overview

This section of Colorado Highway 119 provides East-West access from Boulder to Nederland.  Boulder Creek winds through the canyon adjacent to the highway.  Intense rain in the mountainous terrain surrounding CO 119 saturated the steep embankments and triggered the movement of rock, mud, and debris with the runoff down the mountain slopes and onto the highway in several locations.  The runoff flooded roadside ditches and clogged drainage culverts causing floodwater to flow over the highway and deposit debris.  There was damage to ditches, embankments, guardrails, and pavement.  The excess rainfall increased flows in Boulder Creek causing erosion and undermining of the roadway embankments and shoulders, resulting in roadway failures in several places.

Emergency (Temporary) Repairs

CDOT maintenance removed large amounts of rock debris from the highway surface and repaired numerous material slides along the canyon slopes adjacent to the highway.  Damaged embankments, ditches, culverts, and guardrail were repaired and sections of pavement loss were filled and repaved.

Permanent (Long-Term) Repairs

Permanent repairs will include removing and replacing materials placed during emergency repairs, excavating slope failures where necessary, reconstructing embankments, and reestablishing native grass seed and erosion control to slopes that were disturbed during ER work. In elongated areas with major road damage, the road width template is being analyzed to see what the cost/benefit ratio is to build a wider road.  

Estimated Timeline

  • Est. Design Start: Fall 2014
  • Est. Construction Start: Spring 2016

Estimated Budget

  • $4 to $10 million

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.  Along this corridor, there are several proposed site resiliencies that will be determined during the initial design phase of the permanent repair project.