Silver City residents were hit with unexpectedly high water bills at the end of June and the water company says a software problem is to blame.WATCH KATRINA'S STORY BELOW Silver City water bills spike amid software error and infrastructure woes"I had a resident reach out to me. Their water bill went from $121 to $527," said Mayor Joseph Jaworski.His own household also got one of those high bills."Yeah, so our water bill for a family of six typic…