The North Carolina Department of Transportation's (NCDOT) Division of Aviation and its Environmental Analysis Unit are using UAS to fight invasive plants.

As part of its environmental mitigation for the construction of the new Basnight Bridge over Oregon Inlet, NCDOT is responsible for battling an invasive plant called Phragmites that has overrun the area around Bodie Island Lighthouse.

In search for an alternative to using traditional airplane- or helicopter-based herbicide spraying, the NCDOT Environmental Analysis Unit went to the Division of Aviation to explore the use of UAS for these operations.

Recently wrapped up for the 2019 season, the project showed that UAS provide a “more targeted and efficient spray operation” than traditional methods. NCDOT notes that UAS use less of the herbicidal spray thanks to the ability to program them to target a specific area. They can also be flown safely at low altitudes to reduce the amount of herbicide blown away by wind.

UAS also take away the need to step through potentially dangerous terrain, or disturb other plant and animal life, because they can be equipped with cameras that allow officials to monitor areas.

“The drone has minimal impact on the surrounding area,” says Morgan Weatherford, environmental modeling team lead with the NCDOT Environmental Analysis Unit.

“It was easier to avoid harming native species, better targeted, and quick to mobilize - great for somewhere with unpredictable weather like on the Outer Banks.”

With no need for plane and helicopter pilots to fly low while applying the herbicide, UAS are considered a safer and more cost effective option that manned aircraft for these types of operations. Bodie Island Lighthouse also doesn’t need to be closed to the public while these operations take place.