Stormwater and its ferocious ravages on Waiheke’s essentially hilly terrain has troubled our minds a lot in the last 18 months.
The sight of trucks worth millions standing in stormwater up past their windows in Tahi Road yards in March 2017 was just a start – businesses closed, livelihoods were in jeopardy and road culverts spouted water across beaches, out of drains and down through private property on steep bush slopes.
There has recently been some action. Council has now laid out plans to run a drain along the boundary of the Tawhaipareira wetland past the vast concrete dam which is the island’s refuse transfer station (confirming what any lay person might have thought all along about responsibility in the devastatingly flooded catchment).
Meanwhile, council culverts disgorging into private bush also disappeared after negotiations were concluded with Trig Hill residents on the receiving end of an astonishingly powerful road runoff.
Warning signs were there. A few years ago, island real estate agents had 100 sections for sale. Few of them are left. Inevitably, infill and development of new properties have increased site coverage and impermeable surfaces and all that water has to go somewhere.
Meanwhile, the council has been dishing out consents for development but without thought to supporting infrastructure.
Early this month, barrister Stuart Ryan spoke on the island to a packed seminar on liability for stormwater discharge and the legal remedies available to those affected.
A common law cause of action arises “when water escape occurs and the escape is not in accordance with an easement, a statutory right or the common law right of natural servitude, he said.
“Natural servitude” is recognised as an inherent property right in New Zealand law. It says a lower landowner must accept the natural flow of water from a higher landowner and the higher landowner may discharge, onto the lower land, water that would normally fall there (as long as it is in the natural use of the land), he said.
“This includes rainfall that has accumulated on the higher land for instance.”
However, the natural servitude doctrine is subject to several critical limitations.
“The higher landowner is not entitled to discharge onto the lower land any ‘foreign water’, that is, water that has been brought onto the land from a different water source.”
Nor is the higher land owner allowed to cause damage to the lower land by artificially altering the natural flow of the water, when damage did not occur when the land received only the natural flow discharge. He could not tar-seal a road and thus increase the velocity of the natural flow to the extent that it caused damage to lower land when no damage had occurred previously.
While “ordinary and natural use” of land is a question of fact to be considered separately in each case, there are precedents, said the barrister, a specialist in RMA law.
Ploughing on agricultural land is held to be natural use, but not the drainage of a swamp; clearing an old drain with the consent of the lower landowner is deemed natural, yet the construction of a shed on the boundary of the higher land was not.
“The key points to remember appear to be that the higher land owner is entitled to discharge to lower land any water which falls naturally on the higher land, as long as it is done “naturally”.
“The higher landowner is not entitled to discharge ‘foreign’ water that has been accumulated from other sources or catchment onto a lower land.”
Which sounds plain enough and Ryan’s paper – considered definitive on the issue – says that local authorities, network utility operators, contractors, engineers and consultants supervising works, all face the risk of potential liability and territorial authorities, consulting engineers and contractors have been prosecuted for water-related offences. Councils are not permitted to offload the liability on to CCOs.
Ryan also pointed out their obligation under the 2002 Local Government Act to adopt more rigorous assessment and planning for asset and infrastructure management.
On the island, we have a new climate and tropical deluges rapidly fill existing drains and overwhelm infrastructure. As any farmer knows, if you don’t get cambers, water tables and culvert volumes right, nature will take out your farm track without mercy.
The only way to eat the elephantine roading and stormwater shortfalls we have on Waiheke is to make a start and demand good practices, good engineering, meaningful audits – and respectful attention to citizens who often know the issues best.
The future is unknowable but the sooner we sort out the responsibilities and issues like those in low-lying Blackpool, the better we will ride out the coming changes. In the hands of obfuscating officialdom, delay will be a deadly form of denial. • Liz Waters