The Northern Territory's water provider remains mystified as to why a tiny island community of 1,800 people is consuming an estimated 2.5 million litres per day.

After weeks of investigation, Nigel Deacon from Power and Water Corporation (PWC) said it was no closer to resolving the astronomical consumption figures for the Bathurst Island community of Wurrumiyanga.

"At Wurrumiyanga the daily consumption per person is around about 1,300 litres per day, so that's a huge amount and it's probably around about four or five times sustainable levels."

At the same time, locals have been complaining of water supply problems for more than a month.

Tiwi Islands Regional Council chief executive Marion Scrymgour told ABC Radio Darwin early in October that low water pressure was affecting local businesses.

Map Wurrumiyanga map

She said grass on the community's football fields had browned and that council had to close on at least one day because amenities had stopped working.

Mystery over cause

Even late at night, when water usage would ideally be close to zero, Mr Deacon said certain areas of the island were consuming about 23 litres of water per second.

"We'd like to see zero, but something around about a tenth of that would be appropriate," he said.

"That's a huge amount of water going somewhere and that's the thing we need to find."

Nigel Deacon says the exact cause of the high consumption remains a mystery. ( ABC Radio Darwin: Jesse Thompson )

PWC teams last week conducted section testing on the island, meaning they were narrowing down areas of high consumption to get a better sense of where the water was being used.

Running taps targeted

Council Mayor Gawin Tipiloura said he had been told by PWC teams that the issue was partly due to people letting taps run.

"Community members say the pressure is pretty low and the only time the pressure is really good is at night," Cr Tipiloura said.

The council would work with the community to improve awareness, he added.

"It's just improving the communication with Power and Water and then feeding it out to the community.

"If we can get that improved, then hopefully things will go our way in terms of doing the right thing and being able to not have any issues."

"People are not aware that there is a water issue," Mr Deacon added.

"Because Wurrumiyanga has got such a great supply, they probably think it's a limitless supply.

"People probably don't turn off taps as much as they should, and probably the property owners need to be conscious of the fact that they do need to get those plumbers out as soon as possible to attend to leaks or to leaking taps."

Locals urged to report leaks

Complicating matters is that some of the infrastructure issues might be in the plumbing between a water meter and its premises.

"So we're responsible up to the outlet of the meter," Mr Deacon said.

"Beyond that, people need to be looking to fix their own leaks."

That means some of the repair work could involve the Department of Housing and Community Development.

In a statement, the department said it was aware of the leaks and had been working with PWC to investigate and resolve them.

"This includes frequent inspections and via different mediums, consistent messages to tenants about reporting repairs, and how to report any water leaks and water usage with assistance from interpreters," the statement said.

Mr Deacon said the island's water supply wasn't at risk, but a new bore field might need to be built if new houses were constructed and current water usage wasn't reined in.

He advised residents to urgently report leaks.

"The problem is we're using that bore field at its capacity," Mr Deacon said.

"We'll see the demand start to level out now as people stop using so much water outdoors because of the wet season, but we do need to see everyone take serious action to arrest the long-term growth in demand."