Technology and Collaboration Drive Yellowstone Road Recovery
In June 2022, a bloated Lamar River ripped through Yellowstone National Park, eating up banks, trees, and earth while swallowing entire road sections. Many communities found themselves isolated, grappling with damaged roads and washed-out bridges.
At the time, RESPEC’s Water & Natural Resources (WNR) experts had been working on a bridge replacement project in Yellowstone with Jacobs Engineering. After the floods ceased, they turned their attention to immediate road recovery, combining efforts with Western Federal Lands to design and construct roads in 4 months, quickly restoring critical road access to communities before the winter.
But Yellowstone bore new scars. A jagged riverbank with a 60-foot drop carved by the Lamar River lay near an existing road, threatening its integrity. The National Park Service asked if our team could monitor slope stability with LiDAR, using both ground-based and drone platforms, to determine if failure was imminent.
At the time, RESPEC’s Water & Natural Resources (WNR) experts had been working on a bridge replacement project in Yellowstone with Jacobs Engineering. After the floods ceased, they turned their attention to immediate road recovery, combining efforts with Western Federal Lands to design and construct roads in 4 months, quickly restoring critical road access to communities before the winter.
But Yellowstone bore new scars. A jagged riverbank with a 60-foot drop carved by the Lamar River lay near an existing road, threatening its integrity. The National Park Service asked if our team could monitor slope stability with LiDAR, using both ground-based and drone platforms, to determine if failure was imminent.
"With drones, you get a top-down view, and there’s obliqueness on a vertical wall that you’re not going to see much. We decided a terrestrial LiDAR was the best way to monitor the slope."
// Kevin Eischens, RESPEC Surveyor
LiDAR is a remote sensing technology that uses laser beams to measure distances and create 3D maps. Kevin Eischens, our Anchorage-based surveyor in our Infrastructure (INF) unit, flew to Yellowstone to assist our WNR Bozeman team, using a Trimble SX12 Scanning Total Station and terrestrial LiDAR technology to capture data in two areas of concern.
“With drones, you’re getting a top-down view, and there’s obliqueness on a vertical wall that you’re not going to see much,” says Kevin. “So, we decided a terrestrial LiDAR was the best way to monitor the slope.”
A view of the damage from the road
On April 4, 2023, Kevin worked with the WNR team to set up a base scan of the areas. During the second scan, only a few weeks later, the tripod began to sink into the ground—a sign that erosion was already impacting the riverbank.
After each series of upstream and downstream scans, we supplied the LiDAR point cloud to our partner BGC Engineering to analyze the embankment’s volume changes and micromovements. The data indicated small changes; however, it appeared to be a continuation of the previous erosion. What was once at the top had now fallen to the bottom of the bank.
LiDAR scan of the streambank from April 7, 2023
LiDAR scan of the streambank from April 27, 2023
With periodic scanning, the data offers insights into the rate of the bank’s erosion and whether the road may eventually need to be rerouted, according to Kevin. For now, the most vulnerable portion of the road was moved upslope, farther away from the river.
The work between INF and WNR solidified a great reciprocal relationship between the units that gives our clients and partners immediate answers—and eventually brought WNR up to Alaska to help INF on a major project. But for Yellowstone, we found that technology and collaboration can make all the difference in the face of natural disasters and unforeseen circumstances.