Seabed sands to feed a growing region (paper no. 11) 

Benson, A.; Hume, T.; Smith, Q.; Bell, R. G.; Fenwick, J. 

 

 

 

Chapter in book 

Nearly one third of New Zealand's population, 1.2 million people, live in theAuckland region, and most (90%) people live within the existing metropolitan area. It is the fastest growing region in the country, adding 50 people every day. Projections suggest that by 2050, the region could be home to between 1.6 and 2.2 million people. To grow the region feeds upon sand. Sand is consumed, approximately 250,000m3/yr, for construction activities, roading, horticulture, sports fields and more recently beach nourishment. The shallow nearshore seabed provides the bulk of the aggregate for the concrete industry. There are two major source areas, the Mangawhai-Pakiri embayment, a 30 km long embayment on Auckland's northeast coast, and the Kaipara Harbour, a large tidal inlet system on the west coast. Extraction of sand is governed by the Resource Management Act (RMA 1991), which requires a permit to be obtained and a precautionary approach to be adopted where the effects(e.g., erosion of adjacent shores) and sustainability of the operations are uncertain. This paper describes the approach adopted in issuing interim consents, the different technical approach to investigations undertaken in these two different environments, what we learnt about the sand systems and the potential effects of extraction. 

 

sand mining; pakiri; Kaipara harbour; resource management act; New Zealand; Biogeophysical; mangawhai