Wallow Fire out, but flooding and erosion dangers remain

Dennis Wagner in the Arizona Republic: A few days after the Wallow Fire blew up in the White Mountains in May, Chris Nelson began work to save the forest from rain. Planning for a flood in the midst of flame may seem incongruous. But as a U.S. Forest Service expert on wildfire rehabilitation, Nelson knew that erosion caused by Arizona's summer storms would pose a threat nearly as great as the billowing inferno.

"The biggest concerns from a wildfire are the flooding and the loss of soil afterward when the monsoons hit," said Nelson, watershed program manager for the Apache-Sitgreaves National Forests. While flames consumed the backcountry, Nelson and other scientists raced to prevent the kind of secondary destruction that would harm the forest even further.

Higher-than-normal precipitation was forecast within a few weeks, possibly the most rain in 25 years. Absent a military-efficient response, Nelson said, the scorched forest floor might wash away in mudslides, tearing up roads, inundating communities. After the 2010 Schultz Fire, which was a fraction of the size of the Wallow, flash flooding swamped dozens of homes near Flagstaff and caused the drowning of a 12-year-old girl.

Once critical topsoil is washed away, grasses, trees and other plants struggle to grow back. When habitat is damaged, wildlife stays away. The Forest Service's answer to that threat is a program known as Burned Area Emergency Response, or BAER. It is designed to protect lives, property and cultural resources such as artifacts and petroglyphs in fire-ravaged woods by removing trees that may topple and other public-safety hazards, as well as stabilizing soils and salvaging burned trees....

Wallow Fire and Horseshoe Two Fires (lower left), Arizona. NASA satellite image, acquired midday, June 12, 2011