"It's estimated now at just over $15 million," Walker said.
In the immediate aftermath of the storm, state road crews focused solely on making roads passable. Heavy debris in many places was simply moved off the road and set aside.
Mattox said crews would then come in later to clear the debris along those roads.
But Walker said that after crews went out and surveyed the amount of debris left behind, they realized it would be a major feat.
"It was a storm the likes of which we have never seen," he said.
Rather than having highways crews finish the work, the department bid out 11 different contracts in early December to allow private contractors to finish the work.
The contracts, totaling nearly $3 million, cover the clearing of 1,250 miles worth of roads in Barbour, Webster, Braxton, Upshur, Preston and Taylor counties.
Walker said that when you include the road and right-of-way width, those contractors will have about 4,900 acres of land to clear.
That's roughly 7.6 square miles of land covered in debris.
Walker said the sheer volume of wood and other waste that needs to be removed from the area is enormous.
"Secretary Mattox had heard it described by one of our maintenance folks as being the size of a football field and with debris piled over 80 stories high," he said.
That would be nearly four times as high as Charleston's Laidley Tower.
Officials said the projects could last through the spring.
"We will still be involved in cleanup through April," Walker said.
As for the derecho, FEMA will reimburse the state once the projects are complete. But it could be some time before the state gets the money.
Barring any further catastrophes, Walker said the $6.5 million transfer made in December should be enough to cover road fund costs until the state receives money from FEMA.
Contact writer Jared Hunt at jared.h...@dailymail.com or 304-348-5148.