chch.live the line the Crown drew

The red zone

After February 2011 the Crown classified the damaged ground: where repair could begin, and where "land repair would be prolonged and uneconomic". The red line is the second half of that sentence, 831.7 hectares in 113 mapped areas: the Ōtākaro Avon’s banks, the estuary margin, and the Port Hills streets that could not be made safe. The suburbs behind the line were progressively bought out and cleared. This is the boundary as the council still publishes it.

Mapped areas
113
Red hectares
832
Suburbs it crossed
25
The event
2011
the February shake

The line, drawn

AddingtonAranuiAvondaleAvonsideBeckenhamBelfastBexleyBottle LakeBromleyBrooklandsBurwoodCashmereCass BayChristchurch Central CityCliftonCorsair BayCoutts IslandCracroftDallingtonDiamond HarbourEdgewareFerrymeadGovernors BayHeathcote ValleyHillsboroughHuntsburyKaingaKennedys BushLinwoodLytteltonMairehauMarshlandMerivaleMoncks BayMount PleasantNew BrightonNorth New BrightonNorthwoodOpawaOuruhiaPAPANUIParklandsPhillipstownPort LevyRedcliffsRedwoodRichmondRichmond HillSaint AlbansSaint MartinsScarboroughShirleySomerfieldSouth New BrightonSouthshoreSpencervilleSpreydonSumnerSydenhamTai Tapute-onepoto-taylors-mistakeWaimairi BeachWainoniWalthamWoolston

The red-zone boundary as the council publishes it, over the suburb outlines. Two stories in one colour: the flat land too damaged to repair economically, and the hillsides too dangerous to live under. Kaiapoi’s zones sit in the same classification further north.

Where it fell

Dallington 129.7 ha of mapped zone inside the outline, 98% of it Brooklands 78.1 ha of mapped zone inside the outline, 11% of it Heathcote Valley 69.1 ha of mapped zone inside the outline, 8% of it Bexley 66.3 ha of mapped zone inside the outline, 31% of it Burwood 59.9 ha of mapped zone inside the outline, 10% of it Avondale 58.9 ha of mapped zone inside the outline, 27% of it Avonside 49.3 ha of mapped zone inside the outline, 41% of it New Brighton 38 ha of mapped zone inside the outline, 9% of it Sumner 30.1 ha of mapped zone inside the outline Governors Bay 29.1 ha of mapped zone inside the outline Richmond 27.4 ha of mapped zone inside the outline, 15% of it Southshore 14.2 ha of mapped zone inside the outline, 13% of it Lyttelton 11 ha of mapped zone inside the outline Redcliffs 10.8 ha of mapped zone inside the outline, 6% of it Wainoni 8.2 ha of mapped zone inside the outline, 6% of it Ferrymead 8.1 ha of mapped zone inside the outline Hillsborough 5.4 ha of mapped zone inside the outline Clifton 4.8 ha of mapped zone inside the outline, 6% of it Christchurch Central 3.7 ha of mapped zone inside the outline Linwood 3.4 ha of mapped zone inside the outline Scarborough 3.2 ha of mapped zone inside the outline Cashmere 3 ha of mapped zone inside the outline Moncks Bay 2 ha of mapped zone inside the outline, 5% of it Te Onepoto Taylors Mistake 1.5 ha of mapped zone inside the outline, 9% of it Mount Pleasant 1.3 ha of mapped zone inside the outline

Each mapped area files under the suburb its middle sits in, a ring that spans a boundary counts once, where its centre of gravity is. Rings whose middle falls outside every drawn outline: Kaiapoi, the estuary, the unringed pockets, don’t appear here but are on the map above.

Questions, answered briefly

What was the Christchurch red zone?

The ground the Crown wrote off after February 2011. Land in the residential zones was classified one of two ways: repair and rebuild could begin (green), or "land repair would be prolonged and uneconomic" (red). Inside the red line the government made purchase offers and the suburbs were progressively cleared, the Avon corridor, the estuary edge, and the Port Hills streets that could not be made safe from rockfall.

How big was the red zone?

About 832 hectares across 113 mapped areas in the layer the council still publishes, most of it the flat land along the Ōtākaro Avon and the estuary margin, the rest the Port Hills red zones declared for life risk, not land damage.

Which suburbs were in the red zone?

Parts of 25 suburbs hold a mapped red-zone area in this record: Burwood, Dallington, Avondale, Wainoni, Bexley, Southshore and Brooklands on the flat; Sumner, Redcliffs, Mount Pleasant, Clifton and Lyttelton’s hillside edges in the hills. Kaiapoi’s zones sit in the same layer north of the city.

Does a red-zone line say something about an address?

It says what the Crown’s 2011 classification was, not what stands there now, much of the corridor is park and shared-path land today. A classification boundary is the published record of a decision, not a hazard map and not a finding about any one address’s future.

Also in the earthquakes

The record behind this

Christchurch City Council’s open land layers: QuakeLandZone, the CERA residential classifications of February 2011, kept as the council publishes them and simplified only for size. A classification line is the record of a decision: not a hazard map, not a finding about any one address today, much of the corridor is park and shared-path land now. What the ground did to earn the line is at /liquefaction; what the land that stayed was graded at /technical-categories; the shakes that decided it at /sequence; the faults under it all at /faults.

This page as markdown: /redzone.md · the zone as data: /redzone.json · /redzone.geojson · on the live map: /map?layer=redzone · the story in plain language: the earthquakes explainer.