A water tank used to hold raw sewerage in Franz Josef has lifted out of the ground on five occasions and the inlet pipe is broken, flooding raw sewage into the ground.

A water tank used to collect sewage at Franz Josef pops out of the ground every time it rains heavily, leaving raw sewage to flow into the ground.

The water tank was installed about two years ago by the Westland District Council to collect sewage from a subdivision on Highland Drive in Franz Josef. The subdivision's developer, Lindsay Smith, who is in prison awaiting sentencing on fraud charges, left the sewerage system unfinished.

The 30,000l tank is next to Franz Josef Mechanical Ltd's workshop.

Supplied A water tank being used to hold raw sewerage in Franz Josef has lifted out of the ground on five occasions and the inlet pipe is broken, flooding raw sewage into the ground.

Director Clive Jenkins said he had complained to the council that the tank was lifting out of the ground and toppling over in heavy rain.

"We have a bit of rainfall here on the West Coast and that tank is like a tennis ball in a bucket of water," he said.

The connecting pipes were coming loose and raw sewage was flowing into the ground and leeching into nearby farmland.

"It's human waste flowing into a hole. It's pretty serious. I see it every day and smell it isn't not good. I don't want to open my windows," he said.

He said council contractors, who emptied the tank, often found it empty because the pipes were not connected.

"It's a water tank in the ground. It's not designed for sewage. The council came out to fix it but it pops up every time we have heavy rainfall. Tourists are going by looking at it. You can see toilet paper in the hole. At the moment it's at a 30-degree angle," he said.

Westland's residents and ratepayers group chairman Max Dowell said about five sections were connected to the tank.

He said a qualified drain layer advised the council it would not work before it was installed.

Westland District Council's planning, community and environment manager Jim Ebenhoh said the tank was only brought to council's attention once a couple of months ago when it had come loose in heavy rain.

"We sent Westroads, our contractor, to put it back in. If it has come up again they need to ring the council."

He said the developer had not finished the subdivision's sewerage system so raw sewage had been flowing into a hole.

"The council decided at least to contain this mess. We put in the water tank as a temporary solution and paid to have it emptied regularly. It's not a long term solution. Council did step in and tried to help the situation," he said.

The council would fix the tank if it had come loose.

The regional council had issued an abatement notice on Smith's company, but no action was taken.

The council was working with the company's liquidators.

"It could get legal. Council is not happy that it had to step in. Council had to do something. But we can't pass it onto the ratepayers that cost of a private company. It's a difficult situation," he said.

Smith, a Hokitika accountant, will be sentenced in August on fraud charges.