Abstract:
The implications of land-use and resource management strategies for resource metabolism within the Auckland Region are examined. Sub-regional material flows are used to account for variation in metabolism due to spatially diverse urban development. Alternative growth and consumption scenarios are modelled to forecast the material flow to 2041. Under the prevailing norm, Auckland’s material flows will continue to grow beyond the capacity of identified supply. Confining 70% of residential development to within current urban limits through urban intensification and transit oriented development is found to save 5,400 hectares (ha) of land, 6.8 million tonnes of construction materials and reduce the annual regional rate of energy consumption by 4,100 Terajoules (TJ) per year by 2041. A significant portion of this annual energy saving (3,000 TJ) is due to the reduced consumption of petroleum resulting from less motorised domestic travel. Household energy and construction materials are consumed less primarily due to intensification and increased instances of multi-unit residential development. Cumulative carbon emissions of 5.9 million tonnes would also be saved. However, the subsequent concentration of resource demand will require water and electricity flows that exceed the capacity of some existing reticulated supply infrastructure. The partial decentralisation of bulk supply networks can offset new demand by reducing solid waste and wastewater outputs and reducing total demand on the metropolitan water network, the national power grid and the reticulated gas network. When this is combined with the 70% residential intensification scenario, annual regional inputs of water (20 million m3), electricity (6,100 TJ), Natural Gas (3,400 TJ) and outputs of solid waste (65,000 tonnes), wastewater (26 million m3) and carbon dioxide (1.2 million tonnes) are reduced by 2041.
