Christchurch City Council assures residents that the city's water is safe to drink and use, and that the Council has not issued a boil water notice.

"Households in the Shirley, St Albans, Mairehau and Richmond areas may have received a notice in their letterboxes, but this has definitely not been issued by the Council," says Mark Christison, Unit Manager City Water and Waste. "Christchurch's water is still safe to drink and use."

Mr Christison says residents may notice discoloration in their water, but that this does not mean there is a health risk.

"There was an issue at some of our pump stations with muddy water, but our staff has spent the night flushing out as much as they can, and we're confident that the mains are now all clear. There may be some muddy water still in household pipes, and we recommend turning on a tap to flush this out until the water is clear."

The Council is monitoring the situation. Residents and property owners who still have a concern are advised to contact the Council call centre on 03 941 8999.