Kaipara Quarries Group incorporates Smythes Quarries Ltd and Brookby Quarries Ltd.

Smythes Quarry on State Highway 2, Maramarua manufactures a wide range of products from a large resource of high quality greywacke supplying markets in Auckland, Bay of Plenty, Coromandel and the Waikato region.

Brookby Quarry is a large aggregate resource situated in Brookby, Auckland. With it's comprehensive processing plants Brookby Quarry is able to produce a large range of high quality aggregate for the demands of the Auckland region.