If water was boiled in a pot, it should be left to boil for at least two minutes.
A conserve water notice had been issued for Tapanui and Milton after the flooding. The Tapanui Reservoir was 30% full and the Milton Reservoir was 40% full.
Mr Witt said the council had noticed high water use in those towns which had caused the low levels in the reservoirs.
"People wanted to get cleaned up so there were lots of hoses going."
Residents needed to limit their water use in these areas until the reservoirs caught up, Mr Witt said.
Roads in the Clutha District remained closed due to the flooding.
The roads included Waitahuna Gully Rd, Cullen Rd, Cross Rd, Berwick Rd, Titri Rd, Mitchells Flat Rd, Tulloch Rd and Rutherglen Rd.
Under the Civil Defence Emergency Act 2002, the council was now operating under a notice of local transition period as it moved into the recovery part of the flooding event.
The transition period will last 28 days until August 21.
The notice gave the council powers to carry out essential emergency-related work.