In 2013, severe flooding impacted numerous Colorado canyons and rivers, causing major road and bridge closings or damage. One hard-hit route was State Highway 119 in the north central part of the state; a 15-mile stretch of CO 119 in Boulder Canyon between Boulder and Nederland was in fact completely destroyed in some areas and left impassable. 

A Colorado Department of Transportation (CDOT) project now underway is designed to replace the emergency repairs made at the time of the flooding with permanent repairs, resulting in better storm resiliency and motorist safety along a route that serves as the main access to the town of Nederland and the Eldora Ski area. Beyond providing access for those areas, the canyon is also one of the most popular bike routes in the state. 

Construction on the $31 million Colorado 119 Boulder Canyon Project began in March 2019 and is anticipated to be complete by the end of 2020 (weather issues could possibly push paving work in a few areas into 2021). Zak Dirt of Longmont, Colorado, is the contractor on the project, for which federal disaster recovery funding is covering $12 million of the cost.

Jared Fiel, CDOT Region 4 Communication Manager, relates how CDOT addressed the need for a quick response to the 2013 floods. “There were more than 100 roads and bridges closed or destroyed during this event. Following the floods on September 11, 2013, CDOT was issued the challenge by Governor John Hickenlooper to have all the roads open by Thanksgiving. CDOT beat this goal – but that was just the emergency repairs. In the case of CO 119, essentially the road was put back in place with basic fill so that it was safe, but it would not be able to survive any type of flood event.

“After that, the challenge put down by the Governor was to build back all the roads to be more resilient than they were before. CDOT began a very deliberate process of designing and building the permanent repairs, all with an eye on spending the federal funds for floods within the five-year deadline.

“In designing the permanent repairs for CO 119, the goal was to move much of the roadway in those areas on to bedrock to ensure at least one passable lane when the floods hit again. This is much the same kind of work we had previously done on U.S. 36 and U.S. 34 – blasting into the canyon wall to move the road onto bedrock, to allow the river room to go where it needs to and keep the road safe.”

The Boulder Canyon project encompasses multiple components, including the resurfacing of 13 miles of highway and entirely replacing 2 miles of highway; building concrete islands to improve the roundabout in Nederland; installing new highway directional and safety signage; replacing multiple pipes conveying stormwater drainage under the highway; scaling rock in selected areas to reduce rockfalls on the highway; repairing soft shoulder areas immediately adjacent to the highway; and replacing 29,000 linear feet of concrete or metal guardrail. 

Additionally, materials placed during the emergency repairs will be removed and replaced; areas where the slope had failed in the storm will be excavated; specific sections of the highway will be redesigned and widened; embankments will be reconstructed; and native grass seed and erosion control to slopes that were disturbed during emergency recovery work will be re-established.

The widening is to allow for increased shoulders for safety and sightlines around sharp turns as well as rock catch basins, Fiel explains.

Expanding the Trail

Also part of the project is extension and reinforcement of sections of the Boulder Canyon Trail. The 10-foot-wide, multi-use trail will be extended from Four Mile Canyon to Chapman Drive – adding two new bike-friendly tunnels under the highway and approximately 3,500 feet of length to the trail. As Fiel relates, “In addition to our contractor, Zak Dirt, we have worked with local, state and federal groups to ensure compliance for river work and other environmental guidelines. We also worked with Boulder County to pair up a job they wanted (the Boulder Canyon Trail) with ours since they were taking place in the same area.

“This is a beautiful area which draws hikers and bikers from all over the state. The Boulder Canyon Trail is a popular route through the canyon. Boulder County had already been planning an expansion of the trail, but it would require blasting. Since we were already blasting in the area, it only made sense to combine the efforts.”

The project, especially in its early phases, includes heavy rock blasting, which is critical to the work being done. The purpose of the blasting is to move the roadway in the affected section onto mostly bedrock, Fiel points out. “This is for greater resiliency, to ensure that when or if floods return, the road does not get totally washed away like it did in 2013. Some of the blasting is also to help extend the Boulder Canyon Trail past Four Mile Canyon.

“By moving the roadway onto bedrock where it washed out in 2013, we are confident that at least one lane of passable road will remain following future floods, to ensure residents are not trapped. As far as motorist safety, the blasting is allowing us to create rock catch basins in areas where we typically see rock fall that ends up on the road. When completed, this will allow much of that rock to fall safely off the road.

Managing Closures and Traffic Flow

Delays from single lane and full road closures are anticipated throughout the project’s timeline. Four-hour complete closures for rock blasting and excavation are expected; various long-term single-lane closures will be managed by temporary traffic signals and various short-term single-lane closures will be managed by flagging. Lane closures will add approximately 15 to 30 minutes of time to travel between Boulder and Nederland, and speed limits will be reduced to 25 miles per hour at lane closure areas; a permit-load restriction will also be in effect.

Fiel says that keeping the public informed about project status and the amount of time and possible road closures required, as well as minimizing the impact of the project on traffic flow, has been something of a challenge. “Before the project started, we had a telephone town hall where residents could ask questions of the project team. We also set up a phone and email hotline as well as a text alert system to ensure residents and stakeholders had the latest information – which often changes on a daily basis. 

“When the blasting started, we would close the canyon from 9 a.m. to 11 a.m. and from 1 p.m. to 3 p.m. every day, but the opening and closing was taking so much time and effort, the blasting was not progressing as quickly as we planned, so we moved the Monday through Thursday closures from 10 a.m. to 2 p.m. Adding to the struggle was the fact the rock blasting was not responding the way we originally expected. Because of this, instead of using large cranes and other machinery to place the blasts, we are doing a lot more by hand and it is not as efficient or as fast. 

“This has extended the blasting part of the project several months longer than expected which is very tough on the residents. We have had two public meetings to fill them in on the progress; at the second meeting in December, we announced some changes that are speeding up the process. Blasting is now scheduled to be complete this spring.” 

“Floods will always be a part of living in this incredible area, so ensuring our roadways are resilient is a vital piece of what our job at CDOT is,” Fiel continues. “Colorado was hit hard by the 2013 floods. The CO119 Boulder Canyon project is one of 62 permanent flood repair projects that will be complete in response to this disaster.

“We believe that the work and headaches for commuters and residents which we are going through now will save lives and ensure we don’t have the devastation we had following the floods of 2013.”