Sand is an essential component for making concrete. Currently there is no economically viable alternative to sand in concrete production and without a ready supply of sand, there would be no concrete manufacture.
Sand sourced from the Mangawhai-Pākiri embayment supplies nearly half of the construction sand requirements for the Auckland region.
In the year prior to September 2021, McCallum Bros Ltd® supplied 335,000 tonnes of sand from the Mangawhai-Pākiri embayment into the Auckland ready mix and pre-cast concrete market. The estimated total demand for concrete sand in the Auckland region is 785,000 tonnes, which makes approximately 1.8 million cubic metres of concrete.
A large proportion of the sand supplied by McCallum Bros Ltd® has been delivered to concrete manufacturers who are supplying major infrastructure and commercial projects in the city.
Sand is also used for other purposes, including for industrial, turf and equestrian requirements. This brings the overall demand for sand in the Auckland region to at least 990,000 tonnes per annum or approximately 600kg per person per annum.
The demand for sand is forecast to increase dramatically as the upper North Island continues to grow and more concrete is needed for new homes and infrastructure. It is estimated, for example. that Auckland will require between 9,000 and 13,000 new dwellings every year just to keep up with demand for housing. Concrete will also be required for roads, sewerage and water pipes, as well as public transport infrastructure, to support new communities.
For this reason, it is estimated that under moderate growth forecasts of 2.5%, the demand for sand by the construction industry will increase by up to 40% by 2043. This is an increase of approximately 600,000 tonnes, with total demand expected to reach 1,385,000 tonnes. Total sand demand across all markets is expected to be at least 1,680,000 tonnes at this point.
Recent growth has exceeded these forecasts significantly, with demand for sand increasing by more than 6% in 2021. This demand is driven by the construction sector. If demand for sand was to continue to grow at an average of 5 %, which is absolutely feasible, the volume of sand required in 2043 would increase to at least 2,800,000 tonnes, of which 2,400,000 tonnes would be required for the construction sector. While not all of this sand can be sourced from the Mangawhai-Pākiri embayment or the Kaipara Harbour, it does highlight Auckland requires several sources of high-quality sand of sufficient volume to continue to grow.