Kaipara Harbour is a large enclosed harbour estuary complex on the north western side of the North Island of New Zealand. The northern part of the harbour is administered by the Kaipara District and the southern part is administered by the Auckland Council. The local Māori tribe is Ngāti Whātua. By area, the Kaipara Harbour is one of the largest harbours in the world. It covers at high tide, with exposed as mudflats and sandflats at low tide. According to Māori tradition, the name Kaipara had its origins back in the 15th century when the Arawa chief, Kahumatamomoe, travelled to the Kaipara to visit his nephew at Pouto. At a feast, he was so impressed with the cooked root of the para fern, that he gave the name Kai-para to the district. Kaipara comes from the Māori meaning "food", and meaning "king fern". Geography The harbour extends for some from north to south. Several large arms extend into the interior of the peninsula at the northeast of the harbour, one of them ending near the town of Maungaturoto, only ten kilometres (6 mi) from the Pacific Ocean coast. The harbour has extensive catchments feeding five rivers and over a hundred streams, and includes large estuaries formed by the Wairoa, Otamatea, Oruawharo, Tauhoa (Channel) and Kaipara. A number of small islands off the shoreline are connected to the mainland by mudflats at low tide. The Kaipara Harbour is broad and mostly shallow, as it is formed from a system of drowned river valleys. The harbour shoreline is convoluted by the entry of many rivers and streams, and is about long, being the drainage catchment for about 640,000 ha of land. The harbour entrance is a channel to the Tasman Sea. It narrows to a width of , and is over deep in parts. On average, Kaipara tides rise and fall . Spring tidal flows reach 9 km/h (5 knots) in the entrance channel and move 1,990 million cubic metres per tidal movement or 7,960 million cubic metres daily. The harbour head is a hostile place. Big waves from the Tasman Sea break over large sandbanks about five metres below the surface, two to five kilometres from the shore. The sand in these sandbanks comes mainly from the Waikato River. Sand discharged from this river is transported northward by the prevailing coastal currents. Some of this sand is carried into the Kaipara