Of those 4000, 113 have made submissions — most of which are opposed to granting of water use consents — and 39 are due to speak at Kaitaia's Te Ahu Centre over three days starting on Tuesday.
The Thomases say it's ridiculous to suggest they're unaffected by the avocado boom and the water consents that underpin it.
When they bought the property six years ago it was surrounded by farmland and they had no inkling that would change.
Lew Thomas said ground movement was one of his concerns, given how close their home was to three bores.
''Over a long period of time drawing large volumes of water from the aquifer will cause subsidence.''
Another concern — though it was more for their neighbours in nearby Pukenui — was salt water incursion.
''The aquifer is a pressure vessel, and the pressure keeps salt water out. Take too much water out and salt water will come in,'' he said.
Wendy Thomas said they had exactly that experience when they lived in Townsville, Australia.
A resident in the same subdivision had a large, much-loved garden which she watered heavily from her bore, despite protestations from neighbours.
Within two years every bore in the subdivision was drawing salt water and the Thomases had to drill a new bore into a deeper, less productive aquifer.
Long-time Pukenui resident Eric Wagener said the council was wrong to exclude people like the Thomases.
''We don't believe the process is just because it excludes the right of individuals to have a say about something that affects them, their children and grandchildren. It's just not morally right. Everyone in the community, in one way or another, is affected.''
Wagener said all the community wanted was an assurance that water taken out of the aquifer would be replenished by rain, but they were still waiting for proof — or at least ''a degree of surety'' — that was the case.
''There's nobody in the Far North who is totally anti-development but it has to be sustainable, not at any cost,'' he said.
