Landslides, runoff may contaminate rivers, streams
With impending storms early November 2017, officials worried it could result in toxic runoff from the recent wildfires including ash and debris. The storm is expected to arrive Nov. 3 with up to 4 in. of rain in the Northern Sierra Nevada. In the area, 617 streams already have been affected by the wildfires and the weekend storms raise the concern of damaging drinking water.
Additionally, there is concern regarding potential landslides. There was a landslide in Yosemite June 2017 where 4,000 tons of rock damaged a 100-ft section of Highway 140 through the park.
Officials have taken steps to prevent possible water contamination and landslides by creating a model of potential storm water runoff paths. The regional water board has cleaned storm drains, piled sandbags, and implemented straw wattles in an attempt to contain debris.