Paula and Joseph Anderson fear a motorway slicing through their bush-clad valley south of Warkworth will take at least $1 million off the value of their secluded property.
More than that, they are concerned about the loss of peace from trucks and other traffic thundering over a 500m viaduct which the Transport Agency wants to build into the Perry Rd valley for a $760 million extension of Auckland's Northern Motorway to Warkworth.
The couple bought their 9ha block in 1995, and have spent several million dollars converting a dying kiwifruit orchard to an idyllic retreat with thousands of trees and a European manor-style home.
Although an earlier plan for the 18.5km extension would have required the agency to buy part of their property, a westward route adjustment means it will be built about 500m away, meaning they are not entitled to compensation.
Yet Mrs Anderson, a lawyer who met her American-raised husband while he was an airline pilot and she a flight attendant, has said in a submission for a fast-track planning hearing in April that a real estate agent had told them they would lose at least $1 million from the value of their property.
"This value will be stolen from us without any compensation," she said.
"If this road must be built, it will be far less harmful to the environment if it is constructed in some area which is far less fertile and green than this area, which we are fortunate enough to share with all of the bird-life and animals amid established stands of native trees and clean waterways."
Yesterday, Mr Anderson told the Herald: "This is a property to die for and I hope to die on it.
"Words fail to educate one to the beauty and desirability of this area."
The road will be even closer to his neighbour further north in the valley, Wendy Court, who is dreading waking up to seeing - 280m from her bedroom window - another viaduct cutting through a corner of mature kauri forest.
Although what the agency calls a "kauri eco viaduct" will be less than half the height of the Perry Rd viaduct, Ms Court says three support pylons will rise from the end of her property next to a creek teeming with aquatic life including short and long-finned eels and freshwater crayfish.
Her property was identified in Auckland's unitary plan as containing significant ecological areas, of which she was considered a guardian, yet the Transport Agency seemed able to do what it liked with 0.8ha it wanted from her.
Although the agency says its route will stay clear of the Pohuehue Scenic Reserve further south, a consultant ecologist for its planning applications estimates 374 kauri trees will have to be cleared from a 0.44ha section of the block opposite Ms Court's land.
A Transport Agency spokesman said a previous route alignment included an embankment which would have affected 1.72ha of bush, but that was changed to a viaduct to reduce the road's impact on the kauri.