Silt and slip swallow yard
The silt that covers Shane Hollebon’s backyard in a thick layer began to trickle into his property four years ago.
Hollebon says it appeared at the same time construction began on a subdivision above his Arapiki Way property, in Stoke.
The Three Ridges subdivision on Coster St is one of almost 40 special housing areas around Nelson, an initiative introduced by the then National-led government in 2013 to fast-track housing developments.
As part of the work, the gully behind Hollebon’s house had been filled in, and stormwater running over the infill channelled the dirt down into his property, he said.
‘‘We noticed some silt, two channels that would run down the driveway. Life got busy, and we let it go for a time.’’
Eighteen months ago, Hollebon noticed hollows and loosened cobbles on his driveway. He approached the Nelson City Council, which sent a geotechnical engineer and a developer to inspect the property.
An email report Hollebon received from an engineer said the runoff had nothing to do with the earthworks.
Two weeks ago, the trickle became a deluge when heavy rainfall dislodged dirt and rocks, which piled up against Hollebon’s garage, burying two lawnmowers, a handful of tools, and a vintage Honda scooter.
The next rainfall spread debris across the backyard, covering the cobbles in a thick silt that swallows gumboots and is too much for the short legs of Leonard, the resident daschund.
‘‘Leonard has had more baths in the last two weeks than he’s ever had,’’ Hollebon said.
After the slip, the contractor developing the land, Ching Contracting, engaged its engineering and surveying firm, Land Dimensions, to cover the gully with polythene, installing pipes to channel the water into the drainage system.
Hollebon said he hoped further damage would be limited by the temporary work.
‘‘It couldn’t get any worse now, I hope. There’s not much more that could actually happen.’’
There had been slips on the hillside in the past, he said. ‘‘It’s unstable ground around here. It does concern me they can take a whole valley that has a history of slumping, just fill it, and expect people to be confident in building on it.
‘‘I’d like to see some better planning. What will happen in 20 or 30 years?’’
He said he felt despondent when he looked at the mess through his back window. ‘‘I don’t have the energy to deal with it right now.’’
He had hoped that Ching Contracting would offer to help make things right. ‘‘It would be nice if the developer had come up and said, ‘Hey, we’re sorry, we’ll do what we can to make it better’.’’ However, the company had referred him to his insurer, which had in turn contacted the Earthquake Commission.
Ching Contracting director Andrew Spittal said the problems with the landscape’s instability predated construction at Three Ridges.
‘‘You have to go back to 2011. It started then, well before the work that’s been done at the present.’’
He would not comment on the feasibility or process of building on land with a history of instability.
His team had worked under guidance from geotechnical reports, and development was now ‘‘all signed off’’, Spittal said. However, engineers and contractors were investigating the cause of the slip.
Land Dimensions director Steffan Eden said he did not know what had caused the slip, and there were no indications a slip would happen.
‘‘There are multiple companies involved in any development process, and a multitude or collection of reasons why the slip has occurred.
‘‘The matter is in the hands of insurance companies. I don’t have to answer any questions.’’
A Nelson City Council spokesman said that following the slip, the council contacted the developer, which put measures in place to prevent more slippage while a geotechnical investigation was commissioned.
‘‘Any historic stability issues with the land . . . would have been addressed with the work carried out for the new development.’’