FARMINGTON — Residents along the mountain benches who have been plagued by fire and floods have at least one new tool to ward off the whims of Mother Nature.
Just this week, the Wasatch-Cache National Forest Service completed the construction of flood control structures in the watersheds above the Compton Bench area.
While they will do little to abate the fear of fire this summer, the series of trenches are designed to give residents more protection from the possibility of flooding.
Ironically, the man tasked with supervising the work is Paul Flood, the forest service burn restoration coordinator.
"Our intent with the trenches is to slow down the runoff and get it to soak into the soil before it reaches the lower terrace, preventing further erosion of the gullies that formed during the April 6 rainstorm," he said.
The structures consist of a series of trenches that will intercept runoff and mudflow debris from future thunderstorms and spread it across the Bonneville shoreline terrace, directly above several subdivisions.
A series of eight trenches span nearly a half mile and intersect the natural flow channels to divert the flow of excess water. Each trench is approximately 200 feet long and 3 feet deep.
Flood said that the installation of trenches should reassure residents who worry about recurring flooding. The April 6 thunderhead dropped 2.36 inches in two hours, an amount the 2,000 acres of fire-scarred terrain could not support.
Due to steep slopes and ample sediment along the canyon walls, Farmington and other areas of Davis County are susceptible to flooding and excess debris flow every year. The fire only complicated the already weak section of the Wasatch range.
"We carefully analyzed the slopes in the area to prevent this very thing from happening," Flood said. "For floodwaters to reach the Pointe of View subdivision from the diversion trenches we constructed, water would literally have to flow uphill. However, these homes are still at considerable risk to flooding from future thunderstorm events and will remain so until a more permanent flood control solution can be found."
Gary Cahoon, storm water and drainage manager in Farmington, said a permanent solution is being considered.
"We're looking at a catch-basin designed kind of like a banana that will lie on the bottom of the bench to catch the runoff," he said. "It would be a natural berm enforced with rock and other natural materials."
Following the fire, the U.S. Forest Service assessed the severity of the burn and the resulting potential for floods. Since then, the forest service has worked with city and county officials to take various watershed-protection measures, such as the trenching to reduce flooding and debris-flow hazards.
"What (the fire) did was create unstable conditions up on the mountain," Cahoon said. "It damaged the natural flow paths for water runoff."
Until vegetation has a chance for significant regrowth, he said the mountainside will be in a constant state of change and will be vulnerable to whatever Mother Nature hands out. Until then, the trenches will serve as a temporary barrier for homes and residents and keep the mountain where it is.
E-mail: wleonard@desnews.com