Understanding tradeoffs between high class land and development; recent and future

pressures on Auckland’s soil resources Beyond the Edge

(La Trobe University Melbourne)

Fiona Curran Cournane, Melanie Vaughan, Ali Memon and Craig

Fredrickson Research Investigations and Monitoring Unit

Introduction

• Increasing global population

• Auckland largest city in NZ

• Population forecast to increase from 1.5-2.5m by 2040

• Equates to 400,000 dwellings

• Competition of high class land for rural vs urban vs peri-urban use in NZ

• Soil natural capital- ecosystem services

• High class land = Land use capability classes 1-3

Land Use Capability (LUC) Classification In

cre

asin

g lim

itat

ion

s to

use

LUC Class Arable cropping

suitability

Pastoral

grazing

suitability

Production

forestry

suitability

General

suitability

Specific

reference in

Unitary Plan

Value for

primary

production

De

cre

asin

g ve

rsat

ility

of

use

1 High High High

Multiple use

land

Elite land High

2 Prime land

High to

moderate 3

4 Low

Moderate to

low versatility

5

Unsuitable

Pastoral or

forestry land

Moderate to

low 6

7 Low Low

8 Unsuitable Unsuitable Conservation

land

Low

Objectives

To robustly quantify the amount of high class land that has been lost to urban development

and what is likely to occur using both long term trend and future growth records

High class land =

Land Use Capability (LUC)

Classes 1-3

LUC 1 (<1%)

LUC 2 (12%)

LUC 3 (15%)

What we had

• 28% (124,843 hectares) of the Auckland total land area is classified as elite and prime agricultural land

What we lost......

Urban extension

7,172 ha (5.7%) high class land lost to urban

extension

Disproportionate encroachment onto

high class land

Greenfields equate to 7,842ha (6.3%) loss of high class land

Building consents (52,980) granted = 1.1% (1,395ha) loss of high class land

(415ha outside RUB)

Future growth pressures on

high class land

Why we care

Powerhouse in terms of

outdoor vegetable production

• Pukekohe has some of NZ’s best soils • Unique, effectively frost free climate • Availability of irrigation water • Multitude of freight options • Supply of labour

Because...

Lest we forget....

• Supporting

• Cultural

• Regulatory.....

...ecosystem services soil

natural capital support

Conclusions

• Urbanisation disproportionally encroaches onto elite and prime land and future growth indicates that these tradeoffs will continue

• Real need to analyse the economic benefits and long term sustainability of future development and protection of our valuable soil resources

• True cost of lost ES needs to be evaluated to ensure these values are acknowledged by decision makers