It’s happening here at WSB HQ, just this past hour. We called the appropriate Seattle Public Utilities number – 206-386-1800 – and they noted ours was the fourth call they’ve received. They had no ready response but promised a call from a water-quality inspector. Discolored water is usually the result of sediment getting stirred up in the pipes – usually rust – but the cause can be anything from hydrant testing/use to a break somewhere.