The Hayman Fire of 2002 burned more than 138,000 forested acres southwest of Deckers, greatly increasing the run-off and erosion potential of the surrounding mountains. On July 7, 2006, a 100-year storm dumped more than four in. of rain on the 90-sq-mi., fire-ravaged West Creek drainage basin, creating an 80-ft-wide and 10-ft-high flood, which devastated five mi. of Highway 67.

With 15 sections of roadway scoured from the valley floor, a 100-mi. detour was quickly established.  Within a month, the Colorado Dept. of Transportation quickly assessed the damage, developed a remediation plan, solicited bids for repair work and awarded the project to SEMA Construction.

The emergency repair project included five mi. of roadway reconstruction and channel restoration.  Stream and roadway restoration work included burn and flood debris removal, fish habitat and stream bed enhancements, 53,300 cu yd of riprap revetment, 100,000 cu yd of sediment export, 100,000 cu yd of new roadway embankment, 12,000 tons of asphalt paving, 20,000 ln ft of culvert pipe, numerous drainage structures and 50 acres of revegetation and stabilization—all to be completed before winter.

The channel work was conducted under live water conditions, and SEMA worked closely with CDOT, Colorado Department of Public Health and Environment, U.S. Corps of Engineers, Douglas County and Colorado Division of Wildlife to assure environmental protection. 

In addition to the unique stream bed work, this project was extremely sensitive to maintaining local traffic, using pilot car operations to navigate the dangerous route. This required tremendous coordination efforts between construction forces, traffic control providers and the Colorado State Patrol to ensure public safety while allowing fast-paced reconstruction work. 

The on-schedule grand reopening of the roadway took place on October 31, 2006, 62 days after the start of repairs. Final vegetative stabilization, wetlands plantings and project close-out work were completed in spring 2007 when weather conditions allowed for final reclamation. 

Highway 67 Emergency Repair
Deckers

Silver Hard Hat Award

The Colorado Department of Transportation’s $11.4-million Keystone Hill project on State Highway 145 is located five mi. west of Telluride. S.H. 145 is the only access to the town and the vast majority of traffic funnels through the bottleneck created by the steep, side-cut roadway.

Kiewit Western Co. added a climbing lane, six-ft-wide shoulders, seven retaining walls, guardrail and drainage improvements to improve safety. With an abbreviated construction season caused by early snowfall and a late spring thaw, crews worked double shifts to complete the project on schedule by November 2007.

The steep mountainside and drop-off angles of 60 degrees made it impossible to simply add fill material to the outside roadway grade. Construction of retaining walls was challenged by zero clearance to expand the roadway.

A bench was pioneered across a steep slope to provide access for drilling soil nail walls. More than 44,290 ln ft of soil nails were punched in slide material to stabilize the slope for construction of MSE walls, followed by application of shotcrete and grout to stabilize the existing road. Structural concrete caps placed on piling foundations supported roadway fill material and paving.

With no viable detour, maintaining traffic was critical. One lane of traffic was maintained during daytime operations. While this delayed motorists, it resulted in a 20-min. work window each hour. Conducting multiple, simultaneous operations was essential to maximizing overnight road closures. Reopening the road at 1 a.m. each morning required detailed scheduling and cleared waiting traffic.

Major quantities of materials placed included:

 • 17,050 ln ft of vertical micropiles,

 • 14,444 cu yd of excavation,

 • 20,434 cu yd imported fill material,

 • 9,119 tons base course and asphaltic concrete roadway paving,

 • 3,450 ln ft of new guardrail,

 • 12,505 sq yd removal of existing asphalt.

Keystone Hill, S.H. 145
Telluride

Bronze Hard Hat Award

Prairie Gateway is a 917-acre parcel of land located between 56th Avenue and State Highway 2, bounded on the western edge by Quebec Street and to the east by the Rocky Mountain National Wildlife Refuge.

Mortenson started construction on the $70-million infrastructure contract in July 2005, with final landscaping work in the open space and park area completed in August 2007. The first stage of the project required moving and compacting four million cu yd of dirt to construct the main terrace.

The subsequent installation of utilities on the site involved the laying of more than 70,000 ln ft of RCP, PVC and DIP piping. Additionally, more than 14,000 ft of roads and street were built to provide access to the new soccer complex and the Commerce City Civic Center.

In addition to the on-campus work, Quebec Street was re-built and widened from just north of Interstate 270 to S.H. 2. This included reconstruction of about a mi. of 56th Avenue, mostly east of Quebec, and a short section of S.H. 2, including a new intersection, rail crossing and reconstruction of sections of 80th & Rosemary to the north of the highway.

In spite of the new concrete roadway being almost three ft higher at the busy intersection of Quebec and 56th Avenue, the reconstruction work was completed under traffic with only a single weekend road closure. Even the exceptional snowfall of the 2006/7 winter failed to prevent the project team from opening the roads in time for the Colorado Rapids’ first soccer game at their new stadium on April 7.

Prairie Gateway Infrastructure
Commerce City

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