A concern sewage may enter Lake Rotorua through traditional Maori land is creating anxiety for a descendent camping on the land.

Dave Barry, who returned to Rotorua in November after living in Australia for many years, says he's concerned at the possibility the land his grandmother once owned may become waste land through which sewerage will be channeled into Lake Rotorua.

The site lies north of Ngongotaha and fringes the small Awahou community with which Dave has links. Recently, he was made a kaumatua at Awahou Marae.

The land he left many years ago as he voluntarily served in the NZ Army (1969-1975) then in the carpet industry, has been altered, he says.

Once flat, and while it remains arable, the section he overlooks has undergone heavy machinery works.

The land known as Te Kopua swamp appears to be sourced by the Waimihia Stream, a tributary of nearby Awahou Stream.

He says the section has been prepared for piping sewerage over wetlands and possibly into the lake, but not diverted to Rotorua.

'It is our grandmother's land,” Dave says. 'The council have done a proposal we never knew about and they've already brought in a bulldozer and everything, plus they've destroyed a pond and they haven't cleaned it out and it's going to go into the lake.

Overlooking a stagnant pond.

'It's stagnant, it's got mosquitoes and larvae in there, and all sorts.”

'A hop skip and a jump away is Awahou marae.”

A trespass notice has been issued. In his short occupancy, he has found relics of the past; they are stacked in an access area which descends to the lake edge.

'There used to be Pa here once,” he says.

They are also telling reminders of the decades his grandmother lived, the only sign of which is a chimney hearth.

He claims secret deals have been undertaken since it was taken over by Te Tumu Trust, which is responsible for 900,000 hectares of Maori land for nearly 100,000 owners.

Ownership is not Dave's beef, though who and how many owners are involved is uncertain. He fears that the stagnant pool he oversees and which is hemmed in by a beach sculpted by constant southerly winds, will leach into the lake.

He contends if the pool does leach or is not diverted – there are several sewerage pumps in the vicinity – local Maori at nearby Awahou River, Hauraki Stream and Hamurana Stream - will be affected.

'We and our children still like to swim in the lake which has improved,” he says. 'But that won't happen if the sewerage reaches into the lake.”

At first glance, the discoloured water does not seem industrial, or even if it is rural run-off, a current point of contention in the wider Rotorua district.

Trespass notice served.

While issued with trespass, he has been given permission to stay on the land by leases farmer Hilton McLachlan. He also has a key to the farmland gates. But McLachlan's lease expires soon. It will not be renewed.

Dave Barry outside his home bus.

A Mexican stand-off has occurred, it appears. Dave, who still holds the 100m sprint record at Western Heights High School, has neither left the land (he pops out for medical supplies from time to time) nor has he been assailed for trespass.

Within the 100ha, lies 11ha of wetlands and native bush on land of interest to conservationists. To date, in what ostensibly looks a peaceful setting in contrast to historical conflicts, a concentration of 28 bird species claim a sort of avian right to the land.

His stand, he says, has aroused the interest of his fellow kaumatua at Awahou marae.

Widely muttered is a $1million deal. And Chinese interests.

Sewerage was not entering the lake at present, he concedes. He has noted dead fish life (cockabullies). Pumps (long established adjacent the Hauraki Stream) have been installed at Awahou as also Keith Rd, the entrance towards Dave's resident home bus.

It's a moot point whether raw sewerage has already seeped into the lake, possibly a consequence of historical occupancy anyway.

He claims, however, the trust has prevented the pumping of sewerage into the lake.

'I've been monitoring Lake Rotorua since Christmas and the wind is always coming back this way and washing all the lake water up the rivers,” he says.

'If they're going to release sewerage water into the lake, it's going to destroy those two rivers – and one of those rivers (Awahou) is town supply.

'I've been trying to put feelers out to see who's interested and who's not. A lot of people are starting to take notice now of what becomes of what we're actually trying to do.

'I want to be told the truth – to know what to do.”

■ In the preparation of this item, the Rotorua Lakes and Bay of Plenty Regional councils were contacted by this site. The RLC says it may be a regional council matter. The regional council, contacted on Monday, has neither replied to the original request nor to follow-up email.