Nevada County officials have warned people not to swim or use the water in the South Yuba River after it turned yellow Friday.
It is unknown what caused the water to turn, but Nevada County officials are saying that the apparent “high levels of sediment” make for potentially unsafe conditions and have issued a no-swim advisory for the river. The affected stretch of river is from the town of Washington to Englebright Lake.
On Saturday, authorities said preliminary testing showed water sampled from the area had “dangerous” levels of E. coli, and extended the advisory to include Englebright Lake.
The Yuba County Office of Emergency Services said it, too, is monitoring the situation saying the river east of Englebright “appears to have high level of sediments of unknown origin suspended in the water creating potentially unsafe river conditions.”
However, officials in that county have not issued any advisories.
Officials in Nevada County are urging people to avoid contact with the water and keep animals away, as well.