| Selwyn River / Waikirikiri | |
|---|---|
 Selwyn River near Dunsandel, November 2017 | |
  Location of the mouth within New Zealand | |
| Etymology | Translates as "gravelly water", and named after Bishop Selwyn. |
| Native name | Waikirikiri (Māori) |
| Location | |
| Country | New Zealand |
| Physical characteristics | |
| Source | |
| • location | Southern Alps |
| Mouth | |
• location | Lake Ellesmere / Te Waihora |
| Length | 80 km (50 mi) |
The Selwyn River / Waikirikiri flows through the Selwyn District of Canterbury in the South Island of New Zealand. [1]
The river has its source in the Southern Alps and flows east for 80 kilometres (50 mi) before emptying into Lake Ellesmere / Te Waihora, south of Banks Peninsula. Terrace cliffs above the river's upper reaches gave the town of Whitecliffs its name.
For much of its course the river flows through wide shingle channels. In drought years, the river can disappear beneath this bed and seem to dry up completely. This frequently occurs where State Highway 1 crosses the river at the settlement of Selwyn, about 20 kilometres (12 mi) upstream from its outflow into Lake Ellesmere.
In the foothills, the Selwyn flows year-round. On the plains, the riverbed is highly permeable, and the river overlays a deep and porous aquifer. As soon as the river reaches the plains, water begins leaking down through the bed and into the aquifer. In most months, all river-water disappears within 5 kilometres (3 mi) of leaving the foothills. The next 35 kilometres (22 mi) of the river remains dry for most of the year, apart from a small section around the confluence with the permanently flowing Hororata River. About 15 kilometres (9 mi) upstream from Lake Ellesmere shallow groundwater rises back to the surface, and the Selwyn becomes permanent again.
There are six bridges that cross the Selwyn River. These are at: Whitecliffs (Whitecliffs Road), Glentunnel (SH 77), Coalgate (Hororata Road), Hororata (Bealey Road), Selwyn (SH 1) and Irwell (Leeston Road). It is also possible to cross at Coes Ford when the river is not in flood. Chamberlains Ford is no longer a ford. The nearby Irwell bridge provides access to the other side of the river. [2]
Disappearing river flows have significant ecological effects: when the river’s surface water disappears, so does the habitat for many aquatic plants and animals. In response to loss of surface water, aquatic invertebrates and fish must disperse, seek refuge in remnant aquatic habitats, or die. Aquatic plants, algae, and bacteria must form resting stages or die. The dry central reaches of the Selwyn River also constitute a significant barrier for dispersal of invertebrates and for fish migrating between Lake Ellesmere and the headwaters. [3]
The Selwyn river was viewed historically as one of New Zealand’s best trout fisheries. In the 1960s a trout trap at Coes Ford was reported to count up to 14,000 returning spawning trout. In 2017, the numbers have declined to the stage that only dozens of trout could be counted when returning to spawn. [4] The fish in the river have been described as low in number and the majority of the fish are quite small. [5]
The Canterbury Regional Council (ECan) has permitted intensive dairy farming around Selwyn and it has been suggested that this has led to a deterioration in the water quality of the Selwyn river. [6] In May 2021, it was reported that Nitrate levels in the Selwyn River has increased by 50%.
It is no longer recommended that people go swimming in the Selwyn River. Coes Ford was once a well known swimming spot in Canterbury. [7] [8] The water at Coes Ford was reported to be in the worst 25% in New Zealand for total nitrate levels in 2020. [9] The pollution at Coes Ford is thought to come from Silverstream creek, which used surrounded by many of the dairy farms in the area. [10]
Chamberlain's Ford which crosses the Selwyn RIver had an algal bloom health warning issued in December 2020. There were benthic cyanobacteria found in the river. [11] Algal Blooms of benthic cyanobacteria have also been reported at in the Selwyn river at Whitecliffs Domain and Whitecliffs Road in March 2021. [12]
Greenpeace placed billboards in the Selwyn River to protest the degree of pollution in it in February 2020. [13]
The Selwyn River and its gorge were named in 1849 by the chief surveyor of the Canterbury Association, Joseph Thomas, for Bishop Selwyn. The name was later adopted for the township, the district, and an electorate. [14]
The New Zealand Ministry for Culture and Heritage gives a translation of "gravelly stream" for Waikirikiri. [15]
Lake Ellesmere / Te Waihora is a broad, shallow coastal lake or waituna, in the Canterbury region of the South Island of New Zealand. It is directly to the west of Banks Peninsula, separated from the Pacific Ocean by the long, narrow, sandy Kaitorete Spit, or more correctly Kaitorete Barrier. It lies partially in extreme southeastern Selwyn District and partially in the southwestern extension of the former Banks Peninsula District, which now is a ward in the city of Christchurch. The lake holds high historical and cultural significance to the indigenous Māori population and the traditional Māori name Te Waihora, means spreading waters. It has officially had a dual English/Māori name since at least 1938.
Lake Tekapo is the second-largest of three roughly parallel lakes running north–south along the northern edge of the Mackenzie Basin in the South Island of New Zealand. It covers an area of 83 square kilometres (32 sq mi), and is at an altitude of 710 metres (2,330 ft) above sea level.
Leeston is a town on the Canterbury Plains in the South Island of New Zealand. It is located 30 kilometres southwest of Christchurch, between the shore of Lake Ellesmere / Te Waihora and the mouth of the Rakaia River. The town is home to a growing number of services which have increased and diversified along with the population. Leeston has a supermarket, schools, churches, hospital, gym, cafes, restaurants, medical centre, pharmacy and post office. The Selwyn District Council currently has a service office in Leeston, after the headquarters was shifted to Rolleston.
The Rangitata River is one of the braided rivers that helped form the Canterbury Plains in southern New Zealand. It flows southeast for 120 kilometres (75 mi) from the Southern Alps, entering the Pacific Ocean 30 kilometres (19 mi) northeast of Timaru. The river has a catchment area of 1,773 square kilometres (685 sq mi), and a mean annual flow of 95 cubic metres per second (3,400 cu ft/s) at Klondyke.
Lake Alexandrina is a lake located in the Mackenzie Basin of New Zealand's South Island. It lies immediately to the west of the much larger Lake Tekapo and further to the east of Lake Pukaki, located to the north of Lake Tekapo township. It is a shallow lake with distinct indications of glacial origin and is spring fed with an outlet on its eastern shore midway down the lake. The outlet feeds into a smaller lake, Lake MacGregor before feeding into Lake Tekapo described as “Opaque and milky blue” in colour. In the desert terrain of the Mackenzie Plains, Lake Alexandrina is considered as an “oasis of life”. Lake Alexandrina is a Wildlife Refuge and a delight to a fisherman, well documented for its brown and rainbow trout and salmon.
Lake Coleridge is located in inland Canterbury, in New Zealand's South Island. Located 35 kilometres (22 mi) to the northwest of Methven, it has a surface area of 47 square kilometres (18 sq mi). The lake is situated in an over-deepened valley formed by a glacier over 20,000 years ago in the Pleistocene era. It currently has no natural outflows. There is a small settlement at the lake.
Selwyn District is a predominantly rural district in central Canterbury, on the east coast of New Zealand's South Island. It is named after the Selwyn River / Waikirikiri, which is in turn named after Bishop George Selwyn, the first Anglican bishop of New Zealand who, in 1843 and 1844, travelled the length of the country by horse, foot, boat and canoe, leaving in his wake a sprinkling of locations that now bear his name.
Springfield is a small town in the Selwyn District of Canterbury, in the South Island, of New Zealand. The Maori name for Springfield is Tawera.
A losing stream, disappearing stream, influent stream or sinking river is a stream or river that loses water as it flows downstream. The water infiltrates into the ground recharging the local groundwater, because the water table is below the bottom of the stream channel. This is the opposite of a more common gaining stream which increases in water volume farther downstream as it gains water from the local aquifer.
Whitecliffs is a village located in the Selwyn District of the Canterbury region of New Zealand's South Island. It has also been known as South Malvern, and the name of Whitecliffs comes from terrace cliffs above the Selwyn River / Waikirikiri.
Glentunnel is a village located in the Selwyn District of the Canterbury region of New Zealand's South Island.
Dunsandel is a small rural town in the Canterbury region of the South Island, New Zealand. The town is located on the Canterbury Plains just south of the Selwyn River / Waikirikiri and about 40 km south of Christchurch. Dunsandel is a junction town on SH1, halfway between Christchurch and Ashburton, with roads leading to Leeston, Southbridge and Hororata. The town provides an important refreshment stop for main road travellers with eateries and coffee shops, as well as acting as a support town for the rural hinterland.
The Hawkins River is a river of New Zealand. A major tributary of Canterbury's Selwyn River / Waikirikiri, it flows generally southeast from its source to the southwest of Springfield, reaching the Selwyn 10 kilometres (6 mi) west of Burnham.
The Hororata River is a river of Canterbury, in the South Island of New Zealand. A tributary of the Selwyn River, the Hororata has its sources in rough hill country north of Windwhistle, and flows east through the township of Hororata before reaching the Selwyn 12 kilometres (7 mi) northwest of Dunsandel.
The L II River is a small spring-fed river in Canterbury, New Zealand. It rises near Lincoln and flows through very flat farmland, mostly fed by land drainage ditches before emptying into Lake Ellesmere / Te Waihora just east of the mouth of the Selwyn River / Waikirikiri.
Hororata is a village at the northwestern edge of the Canterbury Plains in the South Island of New Zealand. It is located 15 kilometres southwest of Darfield, five kilometres south of Glentunnel, and 50 kilometres west of Christchurch, on the banks of the Hororata River. Hororata, when translated from Maori means "drooping rata". There are a large number of rata growing in the district.
Kelvin John Coe was the Mayor of Selwyn District in New Zealand from 2007 to 2016.
The Hororata Highland Games is an annual event held in Hororata, New Zealand. The Games began in 2011, following the 2010 Canterbury earthquake. The Hororata community had a desire to make a positive change following the damage of the Canterbury earthquakes. The annual event has increased in popularity with 10,000 people coming to the 2016 edition. It has since become New Zealand's biggest Scottish festival.
Susanna Wood is a New Zealand scientist whose research focuses on understanding, protecting and restoring New Zealand's freshwater environments. One of her particular areas of expertise is the ecology, toxin production, and impacts of toxic freshwater cyanobacteria in lakes and rivers. Wood is active in advocating for the incorporation of DNA-based tools such as metabarcoding, genomics and metagenomics for characterising and understanding aquatic ecosystems and investigating the climate and anthropogenic drivers of water quality change in New Zealand lakes. She has consulted for government departments and regional authorities and co-leads a nationwide programme Lakes380 that aims to obtain an overview of the health of New Zealand's lakes using paleoenvironmental reconstructions. Wood is a senior scientist at the Cawthron Institute. She has represented New Zealand in cycling.
A waituna is a freshwater coastal lagoon on a mixed sand and gravel (MSG) beach, formed where a braided river meets a coastline affected by longshore drift. This type of waterbody is neither a true lake, lagoon nor estuary.