The Waihao River is a natural watercourse in the

Canterbury Canterbury (, ) is a cathedral city and UNESCO World Heritage Site, situated in the heart of the City of Canterbury local government district of Kent, England. It lies on the River Stour. The Archbishop of Canterbury is the primate of t ...

region of New Zealand's

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

. It flows into the Wainono Lagoon near

Studholme Studholme is a locality in southern Canterbury in New Zealand's South Island. It is named after Michael Studholme, a pioneer European settler who arrived in the area in 1854. Geography Studholme is situated on the coastal plains of the Wai ...

. The New Zealand

Ministry for Culture and Heritage The Ministry for Culture and Heritage (MCH; ) is the department of the New Zealand Government responsible for supporting the arts, culture, built heritage, sport and recreation, and broadcasting sectors in New Zealand and advising government ...

gives translations of "water of net fishing" or "water with eels" for . refers to the

shortfin eel The short-finned eel (''Anguilla australis''), also known as the shortfin eel, is one of the 15 species of eel in the family Anguillidae. It is native to the lakes, dams and coastal rivers of south-eastern Australia, New Zealand, and much of t ...

Characteristics

Its headwaters are in the Hunter Hills, foothills of the

Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...

, and its

catchment A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

area is . The catchment receives approximately of rain annually. In its upper reaches, the river has two branches, the North Branch and South Branch, which join together at Waihao Forks. The river is well defined, but when it nears the coast, it becomes a

braided river A braided river, or braided channel, consists of a network of river channels separated by small, often temporary, islands called braid bars or, in English usage, ''aits'' or ''eyots''. Braided streams tend to occur in rivers with high sediment ...

and has a

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

of . When it reaches the coast, the river turns and flows northwards, being joined by the Waimate Creek before discharging into the Wainono Lagoon in

, a locality to the east of the town of

Waimate Waimate is a town in Canterbury, New Zealand and the seat of Waimate District. It is situated just inland from the eastern coast of the South Island. The town is reached via a short detour west when travelling on State Highway One, the main No ...

. However, a culvert known as the Waihao Box has been cut into the gravel

berm A berm is a level space, shelf, or raised barrier (usually made of compacted soil) separating areas in a vertical way, especially partway up a long slope. It can serve as a terrace road, track, path, a fortification line, a border/ separation ...

that separates the river from the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...

to provide permanent sea access.

Crossings

The river is crossed by two major roads. State Highway 1 crosses it near the coast between Willowbridge and Morven, while State Highway 82 crosses it inland at

Waihao Forks Waimate is a town in Canterbury, New Zealand and the seat of Waimate District. It is situated just inland from the eastern coast of the South Island. The town is reached via a short detour west when travelling on State Highway One, the main N ...

. Near the State Highway 1 crossing, it is also crossed by the

Main South Line The Main South Line, sometimes referred to as part of the South Island Main Trunk Railway, is a railway line that runs north and south from Lyttelton in New Zealand through Christchurch and along the east coast of the South Island to Inverca ...

railway, and inland, it was formerly crossed by the Waimate Gorge Branch. This

branch line A branch line is a phrase used in railway terminology to denote a secondary railway line which branches off a more important through route, usually a main line. A very short branch line may be called a spur line. Industrial spur An industri ...

closed in 1953 and the bridges have been removed.

Uses

Agricultural activity occurs the length of the river and it is thus a source of irrigation. It is also used for recreational purposes. Fishers visit the river to fish for

brown trout The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morph ...

. It is also followed by a walkway for approximately near Waihao Forks.

Events

The river has been prone to flooding, with eighteen major flooding events occurring in the 20th century. The only decades during which major floods did not occur were the 1910s and 1970s, and major floods occurred every year from 1950 to 1953.

Environment Canterbury Environment Canterbury, frequently abbreviated to ECan. is the promotional name for the Canterbury Regional Council. It is the regional council for Canterbury, the largest region in the South Island of New Zealand. It is part of New Zealand's s ...

and the local council have implemented strategies to reduce flooding, including the maintenance of stopbanks, managing the

riparian zone A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...

to lower erosion, and restricting development to mitigate damage. In 2000, two special needs students aged 13 and 15 drowned while on a school trip to Black Hole, a swimming hole on the Waihao River. This event stimulated a re-assessment of school policies, and partly as a response to the incident, new safety guidelines were issued by the

Ministry of Education An education ministry is a national or subnational government agency politically responsible for education. Various other names are commonly used to identify such agencies, such as Ministry of Education, Department of Education, and Ministry of Pub ...

.Pete McDonald
"The Waihao River Tragedy: When Will They See the Error of Their RAMS?"
''New Zealand Outdoor Instructors Association Quarterly'' 14 (September 2000): 6. In 2004, the mothers of the students sued the high school for breaching its duty of care to the students; the case was settled out of court in September 2007.

References

{{coord, 44, 47, S, 171, 10, E, display=title, region:NZ_type:river_source:GNS-enwiki Rivers of Canterbury, New Zealand Rivers of New Zealand