ASHEVILLE - The city wants to set fires in a forest crucial to the region's drinking water, a move that could head off a "catastrophic" blaze, officials say.

But consistent precipitation that has lasted through Monday could mean plans for Asheville's first prescribed watershed burn might not happen soon.

The North Fork Reservoir, also called the Burnette Reservoir, is one of two manmade lakes that feed the city water system supplying 124,300 customers inside and outside Asheville with drinking water and serving as the backbone to a thriving beer industry.

Why fire?

Surrounding the 5.8 billion-gallon lake in eastern Buncombe County are nearly 15,000 acres of protected forest. Blocked to recreation or public access, the forest acts as a natural filter, stopping dirt and other pollutants from reaching the lake.

But a forest inventory done by local college students under a 2014 agreement with the nonprofit Conservation Trust of North Carolina found accumulated dead wood, leaf litter and shrubbery that could become tinder for a "catastrophic" wildfire, city officials said.

A resulting study recommended using for the first time a series of controlled burns. Over a period of years fire should be applied to nearly 8,000 acres, or more than half of the woods, officials said.

“We can’t take the chance of having nature take its course on the watershed,” said Leslie Carreiro, Asheville water production division manager. “This is a water quality issue.”

Among potential fuel is an "abundance" of dead hemlocks, decimated in recent years by the invasive insect the woolly adelgid, officials said.

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Fire would also facilitate the natural growth cycle for species which require high temperatures for seeds to open.

Rain

The city originally said the prescribed burns could start as early as mid-February, but consistent rain has pushed that back to at least March 13.

The window for spring burns is about six more weeks, said Lee Hensley, city watershed supervisor.

"After early- to mid-April sap begins to rise in tree seedlings which makes them more susceptible to heat damage," Hensley said. Also emerging from the leaf litter, are "desirable grasses and forbs," the water supervisor said, using the term for nonwoody shrubs or bushes.

If the fire doesn't happen in the spring, it could be bumped back to a shorter autumn burn season.

How would the burn happen?

The U.S. Forest Service has agreed to fund the burn because of the watershed's proximity to national forestland. But the state will be responsible for the starting and managing the fire through the North Carolina Forest Service.

NC Forest Service County Ranger Dillon Michael said he can't estimate cost because of variables such as weather that could affect how many acres are burned at a time, but as an example, he said a 26-acre controlled fire in Leicester in 2018 cost $780.

Foresters will use the 70 miles of roads within the watershed as fire breaks and burn off "blocks," with individual blazes. It will take a while to reach the city's ultimate goal with the forest service aiming for 75-100 acres in one season, Michael said.

"We're not going to do 8,000 acres any time soon."

Areas higher than 3,600 feet in elevation will not be burned because the habitat is different and wouldn't benefit in the same way from fire.

A fire will be set only during good air quality conditions, officials said.

Smoke could be visible from the tourist-heavy Blue Ridge Parkway and other local areas, though the forest service will do the burns in ways to mitigate smoke and fire danger, officials said.

MORE:

►Crews blasting rock at the Burnette Reservoir

►Inside Asheville's water treatment plants, a dedicated team keeps H20 flowing even through near disasters

►Lake James State Park to conduct prescribed fires throughout spring