Wash out briefly brings back 'Slate Creek' look to Cd'A River
Photo by MITCH ALEXANDER A shot of the Coeur d’Alene River from Kellogg shows the gray discoloration caused by the washout. The river has since cleared up.
Photo by MARY REHNBORG A plugged-up culvert in the Beacon Light Road area of Mullan.
Photo by MARY REHNBORG The destroyed culvert near the affected homeowner’s residence in Mullan. It was from this washed out culvert that the flow of water and debris made its way to the Coeur d’Alene River.
MULLAN — Longtime Silver Valley residents took in a rare sight earlier this week when the South Fork of the Coeur d’Alene River reverted to its old (yet strangely familiar) slate gray color for a brief time.
Contrary to rumors of a punctured or damaged tailings pond being responsible, the momentary cloudy hue of the river was caused by heavy rain and an ensuing wash out.
According to Panhandle Health District Environmental Science Specialist Mary Rehnborg, a concentrated thunderstorm made its way into the Mullan/Lookout Pass area on June 17 and let loose around 4:30 p.m.
Along with thunder and lightning, the storm also brought torrential rainfall to areas that had not seen heavy precipitation in some time.
That night, a homeowner on Beacon Light Road near Shoshone Park reported to the County that their road was washing out due to heavy sediment and water drainage.
The washout was so intense that the fish in the homeowner’s fishing pond were being swept out onto the land.
Rehnborg and others with PHD arrived to the scene the following day to catalog the damage and determine where the heavy water flow came from.
“We got there the next day and it was obvious that they got hit really hard with a concentrated thunderstorm,” she said.
PHD followed the path of a destroyed culvert and found other drainage ditches completely blocked as well.
“After meeting with them (the homeowners), we jumped in our rig and drove up I-90 to Lookout Pass and we could see that there was a lot of erosion that was coming off the Lookout Pass Ski lot where everybody parks up there,” Rehnborg said. “There was also a lot of gravel and other sediments that had been pulled from alongside the freeway and washed down. There was so much material that it bypassed the first few storm drain intakes and went for the largest culvert.”
It was from this culvert that the sediment and debris filled water flow picked up steam, hit the homeowners property, then ended up in the Coeur d’Alene River.
The storm was responsible for pushing all this debris into the river for roughly 2-3 hours after it had passed.
While the gray colored water understandably had many residents worried of recontamination of the river, Rehnborg is positive that this was an isolated incident and no pollution occurred.
“We actually did do sediment sampling and everything was, as far as we consider, clean,” she said. “It was very low in the heavy metals. Everything was coming from clean sources around Lookout Pass.”
County work crews are currently in the process of repairing the damaged culverts. Shoshone County Public Works Director Jim Cason could not be reached for comment before press time.