ANDY LOADER reviews past and present quarries in the Queen City as it goes through a massive development stage, and asks – where is the rock coming from?
Based on a presentation at the 2017 AQA/IOQ Conference.
TO SUPPLY THE demand for quarry products Auckland has had many quarries developed around the region over the years, and a large percentage of those are now just a memory covered in urban developments.
When I sat down to write this paper I thought about all of the quarries in the Auckland region that have ceased to operate in the fairly recent past and came up with 37 of them. Between them they took out about 10 million tonnes of product from within the close confines of Auckland city.
Today as a city we devour anywhere from 12 million to 30 million tonnes of quarry products in any given year, depending on the economic situation. Although there are 24 quarries still operating in the greater Auckland city, most aggregate for the city is sourced from as far away as Whangarei in the north and Huntly in the south.
The earliest operations
The site of the city’s first quarry is now the Auckland Wintergardens and the second quarry was created in what is now Albert Park, the site of Albert Barracks, one of Auckland’s earliest military fortifications which was built on the previous site of Te Horotiu pa.
The diminutive scoria cone was substantially quarried away and was the only road building material during the establishment of the city. There’s a slight rise in Kitchener Street, which is about the only part of it left.
In the 1920s Mount Eden was probably the second centre of quarrying in Auckland. The quarry was established near Mount Eden prison and the Colonial Ammunition Company (CAC) premises next door. Quarrying continued until the 1940s, by which time the shape of the mountain had been substantially altered. This old quarry was turned into a garden in 1985 by a group of volunteers.
Another early quarry was less obvious and was on Rangitoto Island in the Hauraki Gulf visible from most parts of Auckland city. Rangitoto last erupted only around 550 years ago, building most of the island we see today with around 2.3 cubic kilometres of material, including the main scoria cone at the apex. The quarry took up around 80 acres and was built in the 1880s by the Auckland Harbour Board.
One of the last quarries to stop operating was the Three Kings Quarry started by Winstones in 1922 when it purchased 27.5 acres on the Three Kings scoria hill in Mount Roskill (it was extended to nearly 40 acres in 1938). Gordon Hunter Ltd also quarried scoria at a quarry next door.
Two notable quarries that left a legacy were the Mt Smart quarries, initially run by three different quarrying companies till eventually they were all taken over by W Stevenson and Sons, and Lunn Avenue.
Winstone set up the basalt quarry in Lunn Avenue, Mount Wellington in 1936 and it became the country’s largest quarry with an annual output in excess of two million tonnes at its highest levels.
When the 110-hectare quarry site was re-developed (into Stonefields) Q&M magazine did a story on the final crush of ‘ugly hard’ basalt boulders that had been disregarded in the past as too hard and big. The article was published in the October-November 2008 issue and the boulders were crushed by Adams Landscaping to supply 60,000 cubic metres of aggregate for Stonefields’ foundation and drainage.
The Stonefields development now houses 6500 people (and a school for 500 children) and was completed in 2012. Who would have thought that nowadays people would be paying over a million dollars to buy an apartment in the old Lunn Avenue quarry?
Puketutu Island Quarry opened in the 1950s and hit a peak back when the local airport and treatment plants were being built. It was owned by Wilkins and Davies. When they went broke they were bought out by Winstones in 1988. Cleanfilling commenced about the end of the 1980s and a fill management plan was developed in 1993 to ensure management of incoming fill quality. Puketutu Island closed its doors to both aggregate sales and tipping in 2012.
The NZ Railways Wiri Quarry on Wiri Station Road was used by Railways from the middle of the last century to provide ballast for rail tracks.
This quarry is currently being rehabilitated using the excavated material from the Waterview Tunnel project on State Highway 20. The quarry area (nearly 40 hectares) will be fully rehabilitated and eventually developed into industrial property in five to 20 hectare lots.
Another old quarry turned into a garden is Wrights Watergardens. After the Second World War, the site was turned into a rock quarry that provided much of the hard metal for the roads leading out to the local Glenbrook steel mill. After the quarry was abandoned, noxious weeds and rubbish covered the area for several decades before it was transformed into a four-acre garden, beautiful in all seasons.
What’s left?
The largest quarries left in the region are Drury Quarry and Hunua Quarry.
Drury, owned by Stevenson, opened around 1939 and is now one of the largest and most technically advanced quarries in this country. It also incorporates a quarry based pugmill for producing modified aggregates.
With its greywacke resource, Drury Quarry ranks amongst the biggest producers of aggregate in the Auckland region, employing 35 staff and supplying a large part of Auckland’s requirements (currently approximately 2.5 million tonnes per year).
As such, Drury Quarry is vital to the Auckland region’s economy and its expanding infrastructure, providing an estimated economic benefit of around $40–$50 million per annum according to independent experts.
Hunua Quarry began in the 1920s as a small business sourcing stone and aggregate from a rocky outcrop in the Hunua gorge.
Winstone Aggregates recognised the quarry’s potential to supply the rapidly growing South Auckland area and purchased the main Hunua block in 1955. The quarry is situated within a high quality greywacke rock resource.
To provide for development, neighbouring property was purchased in 1958. This secured the Symonds Hill area for future extraction, and then in 1988 and 1990 adjoining rural land was acquired to ‘buffer’ the quarry zone from developments that may be sensitive to the effects of quarrying. Small holdings neighbouring or in the vicinity of the quarry have also been acquired from time to time.
Over time the quarry process equipment has been updated and improved several times. In 1962 the ageing ‘Ma’s Hotel’ plant was upgraded with one based on the “Singapore” primary jaw crusher. The name was synonymous with the fact that the crusher had been “rescued” from Singapore in the 1940s during WW2.
The machinery was originally installed in Winstone’s quarry at Lunn Avenue (Mt Wellington, Auckland), and after being re-located to Hunua it continued to manufacture road base and general purpose quarry products.
In the mid-1980s a chip manufacturing plant was added to enable production of a full range of concrete and asphalt aggregates, road surfacing sealing chip, as well as the base courses it had previously produced.
The ‘Singapore Crusher’ was decommissioned in late 2000 when a new state of the art processing plant was built. The quarry currently produces about 1.5 million tonnes per annum.
The future
The government’s 30 Year Infrastructure Plan released in August 2015 predicts that Auckland city’s population will grow by another 716,000, which will require another 400,000 homes.
These figures tell us that we need to find, using a conservative estimate, an extra 5,728,000 tonnes of aggregates per year to develop and maintain the infrastructure for that extra population increase.
Overall the Auckland region will be using approximately 17,728,000 tonnes of aggregates per year (2,216,000 people times eight tonnes using a conservative estimate) by the year 2043.
The majority of this product is going to be sourced from outside of the central Auckland city area either from Franklin district and south of there or from north of the Whangaparaoa Peninsula.
Those 17,728,000 tonnes will equate to approximately 886,400 (20 tonnes payload) truck and trailer movements per year to transport this product to the end users.
This is a conservative figure for truck movements as we know that a percentage of the product (20 percent maybe) will not be carted on trucks and trailers, but will need to be carted on smaller vehicles due to customer job requirements, thereby increasing the number of truck movements to somewhere in the region of one million truck movements or more.
Think about that and the fact the nation’s future infrastructure plan doesn’t even mention quarries.
