Christchurch's arch enemy is set to stick around a little longer.

The City Council will continue adding chlorine to two-thirds of the city's water supply, while it works to meet the Government's new water safety requirements.

The Council's due to deliver its Water Safety Plan to the Ministry of Health at the end of next month, which could take up to three-months to review.

In the meantime, Medical Officer of Health Doctor Alistair Humphrey has recommended continued water chlorination at wellheads that haven't yet been approved by the Drinking Water Assessor.

He's optimistic it'll get back to being chlorine free.

"But it is important that we remain safe, and it's also important that we demonstrate that we can keep a safe water supply."

He says the work needs proper funding in order to succeed.

"That is where I want my rates to go, and I'm pretty sure a large part of the Christchurch community wants to retain a chlorine-free water supply and would be prepared to pay for it."