Housing New Zealand (HNZC) officials are descending on the Christchurch suburb of Avonside following complaints from residents they cannot use their toilets, showers or wash clothes or dishes, nearly three weeks after the September 4 earthquake.

About 100 residents in the central city suburb of Avonside rallied yesterday to draw attention to the ongoing problems they were suffering following the 7.1 magnitude quake on September 4.

Many did not qualify for help from local government agencies or the earthquake fund due to massive waiting lists for structural assessments and overloading of current systems. They would also not be able to live in their houses while repairs were carried out and could not afford to pay mortgages and rent somewhere else in the meantime.

Housing Minister Phil Heatley today said officials would visit nearly 150 Avonside tenants whose properties are affected by broken sewerage drains and wastewater disposal problems, by the end of the week.

"No state house tenant will be paying rent for a property judged to be uninhabitable."

The officials would be discussing ways to improve living conditions and make arrangements for anyone needing to leave because of problems with sewerage and waste-water disposal, Mr Heatley said.

Initially HNZC concentrated on the structural soundness and safety of its housing stock and now it was concentrating on the living conditions of tenants and ensuring they were acceptable, he said.

In the last two and a half weeks HNZC has checked nearly all of its 6000 properties in the Canterbury region.

"Initially no one knew how long essential services such as water or sewerage would take to repair. Christchurch City Council has done a fantastic job and all properties now have water. Unfortunately it appears the sewerage and waste water system is going to take longer to repair."

Portaloos provided by the council were acceptable as a short-term solution but HNZC would assess tenants' needs on a case-by-case basis with regard to longer term solutions.

There would be those who chose to stay in their homes and put up with the inconvenience and, as long as it was safe for them to do so, they would be offered a backdated rent reduction, he said.

Earlier Waimakariri District Council said it could cost at least $76 million and as much as $120m to fix earthquake damage to community buildings, roads, water, sewerage and other infrastructure.

The quake and aftershocks wreaked havoc around the district north of Christchurch, especially in the town of Kaiapoi and nearby Kairaki and Pines Beaches.

Council chief executive Jim Palmer said the money would come from insurance, government subsidies and contributions, and council loan funding.

About $1.8m had so far been spent on emergency response work related to engineering services.

Significant progress has been made to get essential services up and running and clean up the worst affected streets, Mr Palmer said.

Water was restored to all Kaiapoi, Kairaki and Pines Beach residents by September 13 and they no longer needed to boil their drinking water.

However, progress on restoring sewerage was slower.

The Pines and Kairaki sewer systems were badly affected and it would be some time before they were operational again, so there would continue to be sewage discharges into waterways, he said.

There had been good progress clearing sewer lines of silt and about 80 to 85 per cent of Kaiapoi now had an operational sewer system in place.

The council hoped to stop discharging sewage into the Kaiapoi River in the near future, when repair work was complete.