| Kaikorai Stream | |
|---|---|
 Kaikorai Stream, Dunedin | |
 Route of the Kaikorai Stream | |
.png)  Mouth of the Kaikorai Stream Show map of New Zealand Kaikorai Stream (South Island) Show map of South Island | |
| Native name | Kaikarae (Māori) |
| Location | |
| Country | New Zealand |
| Physical characteristics | |
| Source | Wakari |
| • location | Otago Golf Club |
| • coordinates | 45°51′19″S170°29′37″E / 45.85539°S 170.49373°E /-45.85539; 170.49373 |
| Mouth | |
• location | Otago Harbour |
• coordinates | 45°55′57″S170°23′25″E / 45.932422°S 170.390194°E /-45.932422; 170.390194 |
• elevation | 0 m (0 ft) |
| Basin features | |
| Progression | Kaikorai Stream →Pacific Ocean |
| Tributaries | |
| • right | Frasers Creek, Abbots Creek, Christies Creek, Coal Creek, Finnies Creek |
TheKaikorai Stream is a short river which runs through the city ofDunedin, in New Zealand'sSouth Island. The stream has origins in the northwestern suburbs of Dunedin, flowing southwest towards the Kaikorai Lagoon.
Originally named Kaikarae byNgāi TahuMāori referencing an event where the stream was a place wherepetrels were caught and eaten, the stream became highly modified during European settlement, and developed a reputation for poor water quality.
The name 'Kaikorai' is a corruption of 'kai karae',Māori for 'eatingpetrels', referring to a Māori explorer whose party is said to have eaten these seabirds while camping at the mouth of the stream.[1] The first references in print media to the Kaikorai Stream date from 1851.[2]
The stream does not have an official name[3] but "official" maps name Fraser's Creek as Kaikorai Stream and do not give any label to the watercourse through Balmacewen.[4] A 2013Land Information New Zealand report on misspelt names suggests the name "should be Kaikarae",[5] and in 2023, the name Kaikarae was recorded as a collected name for the stream, as a part of the Te Waipounamu tangata whenua place names map project, in collaboration with Ngāi Tahu.[6]
New Zealand Company surveyorFrederick Tuckett named the stream "Green River" in 1844, probably related to the nearby offshoreGreen Island (Ōkaihae) and thesuburb of the same name.[7]
The stream cuts through late Cretaceous-Tertiary sedimentary and igneous rocks and Quaternary floodplain conglomerate and colluvium. In the area of Kaikorai Valley College the bedrock is theAltonian (Lower Miocene) (c.17 Ma millions years ago) Caversham Sandstone.[8]
The stream drains the south eastern and eastern slopes ofFlagstaff,Kaikorai Hill and theBalmacewen area, flows through Kaikorai Valley and Green Island and empties into Kaikorai Estuary. Thewater catchment area is 4,100 hectares (10,000 acres) and has about 15,000 residents.[9] There are two branches both sometimes known as 'Kaikorai Stream'.
The branch of the Kaikorai Stream which flows through Balmacewen has itssource in theOtago Golf Club's Balmacewen Golf Course.[10] From here the stream flows mainly throughculverts below Bishopscourt -- a group of playing fields used by theKaikorai Rugby Football Club -- and anintermediate school. This part of the stream is sometimes incorrectly called "School Creek", which is the name of a nearby tributary ofRoss Creek.
Below Bishopscourt, the culvert opens into a stream through the Shetland St Community Garden and Kaikorai Common. On either side are amarae and aretirement village. A pond and areas of swamp and forest and acommunity garden have been developed here in awetland conservation project of the Dunedin Environment Centre Trust.[11] This land was originally intended for ahighway linking Kaikorai Valley toLeith Valley and theDunedin Northern Motorway.[12]
The stream is piped through the suburb ofKaikorai, past theKaikorai Presbyterian Church and beneathsocial housing built on the formerKaikorai Cable Car depot. It continues partly in open stream but mainly in pipes up to 100 years old maintained byDunedin City Council through private residential property.[13]
The Kaikorai Stream culvert is joined bytributaries fromHalfway Bush, then empties into the much largerFraser's Creek.
Fraser's Creek provides the bulk of the Kaikorai Stream's flow, and superficially appears to be the "main" river, and is indeed labelledKaikorai Stream on official maps.[14] Excess water (brought here by pipeline fromDeep Stream in theTaieri River catchment) is discharged from a citywater reservoir.[15] This spilling has taken place since the mid 1970s, providing a source of cool, clear water of high quality that would otherwise not be available in the Kaikorai catchment. In dry weather, about two thirds of the flow of the Kaikorai Stream comes from this outflow.[9] Fraser's Creek flows through Fraser's Gully, a popular recreation reserve clad in nativebush.
From the confluence the Kaikorai Stream flows southwest down the wideKaikorai Valley through the suburbs ofBradford andKenmure. At Bradford the stream flows through the Roslyn Woollen Mills, a formertextile mill where according to legend the colour of blankets being made could be determined by the hue of the river water.[10]
Pupils of the adjacentKaikorai Valley College use the stream foroutdoor education, studying water quality and flow, learningfly fishing and monitoring waste water.[16]
Many industries in Kaikorai Valley discharge waste water into the stream.[10] The industrial area here is one of the few stretches of river withesplanade reserves (providing public access) along its banks.[17]
AtBurnside the river turns west throughGreen Island, mainly in a channel lined withconcrete alongside theDunedin Southern Motorway.
Below Green Island, the stream is joined by major tributary Abbots Creek then resumes a southwest course, reaching thePacific Ocean atWaldronville, where its outflow is alagoon, the Kaikorai Estuary (also known as the Waldronville Lagoon or Kaikorai Lagoon). This lagoon is part of a research project aimed at establishing a national estuarine monitoring protocol. It is inhabited byblack swans, andspoonbills are also sometimes observed.
Though only a short stream some 18 kilometres (11 mi) in length, it has been important to the industrial history of Dunedin. Many local industries have used power from the stream, most notably the Roslyn Mills.
Native aquatic animals in the stream includewhitebait,freshwater crayfish (koura), giantkokopu, longfinned and shortfinnedeels and freshwatermussels.[18]
In 1987, theOtago Regional Council launched a streamscape restoration programme which included restoration ofriparian vegetation and public access to parts of the stream.[18] In 1996 the Dunedin City Council redeveloped itssanitary landfill atGreen Island to reduceleachate in the Kaikorai Stream, while in the same year the Dunedin Environment Centre began restoration work at four sites along the stream.[18]
In 1849 settler Samual Woolley described the stream as of the 'purest water."[18]In 1907The Otago Daily Times described the Kaikorai Stream as "a long continuous sewer" and "a sanitary scandal."[19] A century later, the paper described the stream as a "little battler".[9] while an Otago Regional Councillor described this and other Dunedin streams' water quality as "basically crap."[20] The pollution was, to a large extent, the result of the heavy industrialisation of the lower course of the stream, particularly aroundBurnside, which was the site of afreezing works and cement factory. Other industries which used the streams waters in the early days of Dunedin's settlement included tanneries, stockyards, a flour mill,Kempthorne Prosser's chemical plant, and the Otago Iron Rolling Mills.[21]
The water quality worsens as the stream gets closer to the sea.[22]Macroinvertebrates found in the estuary indicate the water is degraded, while more sensitive species exist near Kaikorai Valley College and the situation improves further upstream.[22]
Major pollution events include an accidental spill oflime from the Dunedin City Council water treatment plant at Mount Grand in 2000 which "killed all aquatic life" including 1,000trout[23] for which the council was finedNZD14,000,[24] and a discharge ofcooking oil from aKFC restaurant in 2011[25] for whichRestaurant Brands was finedNZD15,000.[26]
