Photo: BCWS

The smoke has long cleared and the BC Wildfire Service has published a report on potential hazards in the wake of the Sitkum Creek wildfire.

The lightning-caused blaze forced several people from their homes after an evacuation order was issued. No structures were lost to the flames and all residents eventually returned home.

The Sitkum Creek fire was 1,262 ha in size as of July 28, and was 19 km north east of Cherryville, near Sugar Lake.

“The fire burned the south side of the Sitkum Creek valley from the valley bottom towards Vidler Ridge. The potential post-wildfire hydrological and geomorphic hazards within or downslope of the fire include elevated streamflow, debris floods, debris flows, landslides or rockfall,” the report says of the aftermath from the fire.

“Most of the post-wildfire natural hazards...are related to a series of hydrological changes associated with wildfire. These include increased throughfall of rain and snow due to vegetation loss, rapid melt during spring freshet, or rapid runoff during intense or prolonged rainstorms due to vegetative and soil losses or any soil hydrophobicity.”

The report says some of the areas were “severely burned” and post a high risk of debris floods or debris flows impacting Ryker Road or forestry operations in the area.

“Post wildfire debris floods or flows are anticipated to travel to the valley bottom where they will begin to spread out and deposit at the toe of the hillside. Debris floods are anticipated to travel to Sitkum Creek. Because Ryker Road crosses these streams, in some cases quite close to the stream gully outlets, the likelihood of spatial impact for debris flows and debris floods is rated as high,” the report says.

“As a result, the partial risk rating to the road is very high. Workers and the public should be made aware of the upslope hazards and risks along Ryker Road with signage. Stringent rainfall shutdown criteria are recommended to protect workers in the area and consideration should be given towards placing no stopping signs along Ryker Road to limit exposure to these hazards. Rainfall measured in the valley bottom along Ryker Road may be significantly less than the rainfall accumulation up towards Vidler Peak, where hazardous events are likely to initiate.”

The risk of rockfall impacting impacting Kate Creek Forest Service Road are rated moderate to high.

“During the fire suppression, rockfall was noted along Kate Creek FSR. Rockfall is anticipated to continue for some time after the fire. Signs should be installed indicating the post-wildfire rockfall hazard along the road and recommending no-stopping in those areas. Signs should be placed between the Sitkum Creek crossing and a point approximately 2 km west along Sugar Lake indicating users are entering a hazardous zone,” the report says.