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Fast Topo Maps Keep Boulder Canyon Highway Project on Track

Fast Topo Maps Keep Boulder Canyon Highway Project on Track

Heavy civil contractor, Zak Dirt, founded in 1976, is based in Longmont, Colorado, an hour north of Denver. With comprehensive earthwork and concrete services, the company performs mass excavation, grading, roadwork, water conveyance and storage and utility installation for public and private entities. Among its many notable projects, the company is the prime contractor on the $31 million CO 119 Boulder Canyon Improvements project.

Business Challenge

The $31 million CO 119 Boulder Canyon Improvements project involves the repair of a 15-mile stretch of flood-damaged Colorado Highway 119 between Boulder and Nederland. The one-year project requires the tracking of approximately 41,000 cubic yards of material, among other tasks. The team needs topo maps to help track progress and calculate volume quantities, but conventional survey methods in the steep canyon terrain would be too dangerous and difficult.


Implement a survey-grade drone platform:

It’s easy to see material to be moved – in red – by comparing the current surface to the final design in this image.


  • More reliable, accurate and current topographic maps of jobsite
  • Opportunity to perform complex measurements and analysis
  • Faster, more accurate material volumes quantities from rock scaling
  • Improved site logistics and project progress tracking
  • More streamlined data gathering process for future projects

The $31 million CO 119 Boulder Canyon Improvements project involves the repair of a 15-mile stretch of Colorado Highway 119 between Boulder and Nederland that was damaged during flooding in 2013.

As the lead contractor on this project, heavy/highway contractor Zak Dirt is replacing two miles of highway and stormwater drainage pipes under the highway, resurfacing another 13 miles of roadway, repairing soft shoulder areas to reduce chance of rockfalls on the highway as well as associated embankment reconstruction and re-establishment of native grass on slopes. The entire project is on track for completion by summer 2020, weather dependent.

It’s a challenging and dangerous project, which requires considerable excavation, removal and replacement of materials along the highway and the canyon slopes—a task Zak Dirt is well equipped to handle with a little help from survey-grade drone solutions to plan and track work progress.

On the Rocks

An integral part of the Boulder Canyon project is widening the road and scaling rock faces to reduce the chance of rockfalls. Zak Dirt estimates approximately 41,000 cubic yards of material will be blasted to complete the highway improvement project.

Angelo Mancina, Zak Dirt’s corporate treasurer who also handles GPS surveying, said, “Large and complex earthwork and highway projects, such as the CO 119 Boulder Canyon Improvements project, require considerable material management.” Mancini adds that typically, the contractor relies on topo maps, both before and during a project, to track material removal and ensure design specifications are met.

However, the location of the project in the Boulder Canyon limits survey opportunities. “It would be too dangerous for ground-based crews to survey the terrain from the ground, taking shots up and down a slope,” Mancina said. “There’s absolutely no way that would be done. By the time we did a topo of the canyon and got it back, we would be two months past when we needed it.”

Looking for a way to keep his people out of harm’s way, but still get the invaluable topo data, Zak Dirt looked at drones and visualization platforms, ultimately selecting Trimble Stratus powered by Propeller.

Imaging like this show cut values to final design, as well as a cross section of the most recent flight and the previous flight to highlight changes at the surface.

Material Movement

For the Boulder Canyon job, Zak Dirt is using the Trimble Stratus platform to map project progress, particularly volumes of materials moved, and adapt work scopes as needed.

Mancini said that it’s critically important to measure the volumes coming out of the blasts, adding that dirt moves around nonstop, and a job like this is a continuous cycle of displacing and replacing. Without Trimble Stratus, the Zak Dirt team would have to measure volumes by truck counts and coordinate with the Colorado Department of Transportation.

“Now we can just fly it, do a comparison, and say, ‘Here’s how much rock was taken off the mountain.’ Very simple,” explained Mancina.

To keep track of quantities, they fly the site twice a month while blasting occurs. “Now, for the most part,  we have our files within 12 hours, which is awesome,” noted Mancina. “We’re able to fly it and do cross-section comparisons to where we are at now with the design. The engineer can actually see the cross-section as it is with the design, and they can measure and revise blast slopes as needed.”

The data from the platform is shared among project managers, surveyors, superintendents, engineers, and others within Zak Dirt.

Beyond that, the project team uses Trimble Stratus to show project updates and relay progress reports to owners. “We’ll pull it up with them in the room and show them cross-sections, or we’ll print the reports,” Mancina explained. From there, “we will print them the DXF CAD files,” handing it over to the customer to maintain transparency about where they’re at on the project timeline.

Beyond Boulder Benefits

For the CO 119 Boulder Canyon Improvements project, the topo data is all in one place, which allows Zak Dirt to better coordinate the logistics on the project including vehicle movements and earth moving.

With the reliable, accurate and current topos, the team is spending less time processing, and more time diving into complex measurements, analysis, and creating new insights.

“We’ve used it to make some designs for access; we’ve built some files so we could access down into the river to do some of the work,” explained Mancina. “We’ve flown the site, and then did a volume comparison to see if we have all of the dirt we need right there,” instead of trucking it in from some other part of the worksite.

Bottom line, he said, “We know what we’ve done and what we have left to do.”

The accessibility of the data has started a chain reaction of new or more in-depth ways of using worksite data to track progress, quantities, logistics, and more on this project and future projects.

Mancina summarizes it best: “The most useful is getting the topo done quickly and having accurate information to compare, to get our volumes, or to know how much is left to do. Getting that information fast is often the difference between getting a project done on time or going over.”