Something turned Sonora Creek milky white and watery gray like skim milk Thursday afternoon before sundown, and police and city staff quickly solved the mystery.

City administrator Tim Miller inspected Sonora Creek where it flows under South Green Street and then walked to the Sonora Police Department.

Jerry Fuccillo, the contract city engineer, also walked to Sonora Creek at South Green Street to have a look before 5:30 p.m. Thursday.

Twenty minutes later, Police Sgt. Tim Wertz said in an email, “The creek ran white for a short time today due to a water-based paint being washed off a sidewalk into the storm drain. The paint was knocked over by an unknown subject, and the owner of the property was trying to save his new concrete work from getting more damaged.”

The paint was washed off from Theal and Shepherd, Wertz said.

Questions were also posed to Tuolumne Utilities District and state Fish and Wildlife staff, who did not respond Thursday evening.

Four years ago, white roofing sealant drained off the roof of the Rodeway Inn and turned Sonora Creek white for a time.

Sonora Creek runs through downtown Sonora, flows into Woods Creek, which empties into Don Pedro Reservoir in the Tuolumne River watershed.

Contact Guy McCarthy at or (209) 588-4585. Follow him on Twitter @GuyMcCarthy.