Waihou River

The Waihou River is located in the northern North Island of New Zealand. Its former name, Thames River, was bestowed by Captain James Cook.

The river flows north for 150 kilometres from the Mamaku Ranges past the towns of Putaruru, Te Aroha, and Paeroa, before reaching the Firth of Thames at the south end of the Hauraki Gulf near the town of Thames. In its lower reaches, the river and the nearby Piako River form the wide alluvial Hauraki Plains.

Just before the river reaches the ocean, State Highway 25 crosses the river over the Kopu Bridge, the longest single lane bridge in the country at 463m and the only remaining swing bridge on a New Zealand state highway. The bridge was infamous for the queues of vehicles travelling to and from the Coromandel Peninsula until a new two lane bridge was opened in December 2011.