Planner Sees Clear-Cut Reasons Behind Flooding Of North Idaho Streams
This fall’s flood waters have subsided, but the questions remain in western Shoshone and eastern Kootenai counties:
Are floods coming faster, or more frequently, than in the past? If so, is it because the watershed has been heavily logged?
Shoshone County Planner Harold van Asche thinks the answer is yes on both counts.
“The water used to come up more slowly,” said van Asche, a former emergency services director. “It takes a brave individual in this community to say so, but the more clearcutting they do, the more rapid those peaks are.”
Many people in the county make their living in the timber industry, including van Asche’s son, who is a logger. But enough people are raising the question that Ken Kohli, a spokesman for the Intermountain Forest Industry Association, is ready with a rebuttal.
“The Coeur d’Alene River flooded for centuries before humans were here to record the events, and any suggestion that logging can significantly alter the impacts of major rainstorms is loaded with more politics than science,” Kohli said.
If loggers hadn’t cleared portions of the land, he said, nature would have done it.
The trees were ravaged by disease, and dead trees don’t absorb rainfall, he said. Kohli contends the best way to help the watershed is to cut the firs that are now dying from root rot, and replant the slopes.
When a warm wind or rain hits snow that’s unsheltered by trees, the runoff can be quick. That weather pattern is common in the Coeur d’Alene Basin. However, Forest Service hydrologist Rob Harper isn’t convinced floods are more frequent there because slopes have been cleared.
But Allen Isaacson, a former Forest Service hydrologist, insists “you’re getting a lot more runoff for the same amount of precipitation.”
There’s no disagreement that more rock has moved downstream into the river, making it shallower and more likely to overflow its banks. Between 1967 and 1992, Isaacson said, the river channel at Prichard rose three feet.
The rock comes from many sources, said Harper.
“There’s more road channel crossings that have failed … there’s mine tailings eroding, riverbanks eroding.”
The Forest Service is putting boulders and trees in some streams to slow erosion, and is destroying and reseeding some of the old logging roads.
Even Kohli concedes that old logging roads “created a pipeline to bring the water down into the system, rather than let it flow slowly … We’ve agreed that there are some good reasons to think about putting some of the unneeded roads to bed.”
But industry doesn’t want too many roads closed. Neither do local residents, some of whom have objected when the Forest Service proposed closing some eroding routes that are popular with people who play in the woods.
Mike Beckwith of the U.S. Geological Survey has a hunch that floods come more frequently now. To find out, he plans to review river flow records taken at Cataldo and Enaville since the early 1900s. He’d like to get funding for a more thorough study.
Gayle Bourne doesn’t need a study. The basement of his home north of Enaville fills up whenever the North Fork overflows. He said it’s happening more often, and he’s convinced there’s a culprit.
“It’s not going to get better for a while because we’ve raped the forest,” he said.
, DataTimes