The Piako River is a lowland river system that drains into the

Firth of Thames The Firth of Thames ( mi, Tikapa Moana-o-Hauraki) is a large bay located in the north of the North Island of New Zealand. It is the firth of the rivers Waihou and Piako, the former of which was formerly named the Thames River, and the town o ...

on the

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. Together with the

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 in November 1769, when he explored of the river from the mouth. An older Māori name was "Wai Kahou Roun ...

, it is one of the two main rivers systems which drains the

Hauraki Plains The Hauraki Plains are a geographical feature and non-administrative area (though Hauraki Plains County Council existed from 1920 to 1989 and a statistical Area Unit remains) located in the northern North Island of New Zealand, at the lower ( ...

. It is the dominant river system in the

Matamata-Piako District Matamata-Piako District is a local government area in the Waikato region of New Zealand. It lies to the east of the city of Hamilton. Geography The district encompasses the southern end of the Hauraki Plains and much of the Thames Valley, and i ...

, and on its journey it passes through the towns of

Morrinsville Morrinsville is a provincial town in the Waikato region of New Zealand's North Island, with an estimated population of as of The town is located at the northern base of the Pakaroa Range, and on the south-western fringe of the Hauraki Plains. ...

and

Ngatea Ngatea ( mi, Ngātea) is a small town on the Hauraki Plains in the North Island of New Zealand. It is located 18 kilometres southwest of Thames and 70 kilometres southeast of Auckland. Ngatea lies on the Piako River, eight kilometres south of i ...

. The Piako River has an annual mean flow of (at Paeroa-Tahuna Road), with a total catchment area of approximately . The river system is approximately long, aligned in a north-south direction and occupies much of the central and western

(or more broadly, the

Thames Valley The Thames Valley is an informally-defined sub-region of South East England, centred on the River Thames west of London, with Oxford as a major centre. Its boundaries vary with context. The area is a major tourist destination and economic hub, ...

), extending from

Hinuera Hinuera is a settlement in the Waikato Region of New Zealand's North Island. It is located along State Highway 29, approximately halfway between the cities of Hamilton and Tauranga. It also contains the Hinuera cliffs along State Highway 29. ...

in the south before discharging into the

in the north, five kilometres west of

Thames The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...

. The Piako River has two major stems: the first, and main, stem drains the northern Te Miro-Tahuroa hills, and the Pakaroa Range. The dominant tributaries on the eastern slopes of these hills are the Piakonui and Piakoiti Streams. These streams, together with the smaller Toenepi Stream, converge just south of Kereone to become the Piako River. The western slopes are drained by the

Waitakaruru Stream The Waitakaruru Stream is a major tributary of the Piako River, within the Waikato region of New Zealand's North Island. It should not be confused with the similarly named Waitakaruru River, which is also in the Waikato Region. The Waitakaruru ...

which joins the Piako River at

. As the Piako River progresses north, it is fed by numerous small streams draining the eastern slopes of the Hangawera Hills. The second stem is the

Waitoa River Waitoa is a settlement in the Matamata-Piako District of New Zealand. State Highway 26 runs through the town, and connects to Te Aroha 10 km to the north-east. A Fonterra dairy factory is a prominent blue building in the middle of the town. T ...

, which starts near Piarere. The Waitoa River catchment drains the Hinuera Flats and broad southern Hauraki Plains, before converging with the Piako River in the large wetland known as the

Kopuatai Peat Dome The Kopuatai Peat Dome is a large peatland complex on the Hauraki Plains in the North Island of New Zealand. It consists of two raised domes, one in the north and the other in the south, that are up to three metres higher at the center than at t ...

, northeast of Tahuna. The Upper Piako River catchment also drains the eastern aspects of the

Hapuakohe Range Hapuakohe Range of hills is aligned north-south, between the Waikato River and the Hauraki Plains in the Waikato region of New Zealand. It is separated from the Taupiri Range by an air-gap at Mangawara, where the Waikato flowed about 20,000 ye ...

through small tributaries. The river system is highly modified by intensive dairy farming and associated industry. Given this, the Toenepi Stream - a small sub-catchment of the Piako River - has been extensively used to research the impact of

intensive farming Intensive agriculture, also known as intensive farming (as opposed to extensive farming), conventional, or industrial agriculture, is a type of agriculture, both of crop plants and of animals, with higher levels of input and output per unit of ag ...

on water quality and develop improved farming practices.

Drainage and flood protection

In 1906 work started on cutting the bends in the river below

Kaihere Kaihere is a dispersed Waikato rural settlement on SH27, overlooking the Hauraki Plains. It has a school, hall, domain a rest area and is the starting point for the Hapuakohe Walkway. Demographics Kaihere's meshblock (1069500 includes the ...

Landing. Since the 1930s, considerable flood protection measures have been undertaken on the Piako River and surrounding catchment, especially mainly north of Paeroa-Tahuna Road and the

. The scheme includes river management works, river diversions and channel enlargement, ponding systems, floodway improvements, stopbanks, floodgates and pumps. However, the river flooded again in 2017. A 2018 plan provides for strengthened stopbanks and diversion ponds. The scheme works includes the following: * Main river and tributary channel enlargement and clearing work, * 170 km of stopbanks, * 59 floodgates and * 32 pump stations The scheme provides the following levels of service: * 100-year protection from tidal flooding with freeboard, * 50-year protection from Piako River flooding with freeboard

Piako River Bridge (Ngatea)

The original Piako River Bridge was built in

and opened in 1917. In the earliest days all transport or access to and from the land was either by sea, river or canal, but with the first roads being developed, it was essential that a bridge be built over the Piako River so it could become a main route between Auckland and

Tauranga Tauranga () is a coastal city in the Bay of Plenty region and the fifth most populous city of New Zealand, with an urban population of , or roughly 3% of the national population. It was settled by Māori late in the 13th century, colonised by ...

. Considerable work has gone into restoring the banks of the river, as in winter it is the direct cause of flooding through the low-lying

References

{{coord, 37, 12, S, 175, 30, E, display=title, region:NZ_type:river_source:GNS-enwiki Rivers of Waikato Rivers of New Zealand Firth of Thames Hauraki Gulf catchment