{{Use New Zealand English|date=April 2024}}{{Use dmy dates|date=April 2025}} {{Infobox river | name = Manawatū River | native_name ={{native name|mi|Manawatū}} | name_other = | name_etymology = | nickname = <!---------------------- IMAGE--> | image = Manawatu Gorge New Zealand.jpg | image_size = 270px | image_caption = The [[Manawatū Gorge]] | image_alt = <!---------------------- MAPS --> | map = NZ-Manawatu R.png | map_size = 270px | map_caption = The Manawatū River system | map_alt = | pushpin_map = | pushpin_map_size = | pushpin_map_caption= | pushpin_map_alt = <!---------------------- LOCATION --> | subdivision_type1 = Country | subdivision_name1 = [[New Zealand]] | subdivision_type2 = Region | subdivision_name2 = [[Manawatū-Whanganui]] | subdivision_type3 = Cities | subdivision_name3 = [[Palmerston North]] | subdivision_type4 = | subdivision_name4 = | subdivision_type5 = | subdivision_name5 = <!---------------------- PHYSICAL CHARACTERISTICS --> | length = {{convert|180|km|mi|abbr=on}} | width_min = | width_avg = | width_max = | depth_min = | depth_avg = | depth_max = | discharge1_location= | discharge1_min = | discharge1_avg = {{convert|102|m3/s|cuft/s|abbr=on}} | discharge1_max = <!---------------------- BASIN FEATURES --> | source1 = [[Ruahine Ranges]] | source1_location = | source1_coordinates= {{Coord|40|0|53|S|176|7|1|E|}} | source1_elevation = | mouth = [[Tasman Sea]] | mouth_location = [[Manawatū Estuary]], [[Foxton Beach]] | mouth_coordinates = {{coord|40|28|S|175|13|E|display=title,inline|region:NZ_type:river_source:GNS-enwiki}} | mouth_elevation = [[Sea level]] | progression = | river_system = | basin_size = {{convert|5899|km2|mi2|abbr=on}} | basin_landmarks = [[Manawatū Gorge]], [[Manawatū Estuary]] | basin_population = | tributaries_left = [[Tamaki River (Manawatū-Whanganui)|Tamaki River]], [[Pohangina River]], [[Oroua River]] | tributaries_right = [[Mangatewainui River]], [[Mangatoro River]], [[Tiraumea River (Manawatū-Whanganui)|Tiraumea River]], [[Mangahao River|Mangahao]], [[Tokomaru River]] | waterbodies = | waterfalls = | bridges = | ports = | custom_label = | custom_data = | extra = }}
The '''Manawatū River''' is a major river of the lower [[North Island]] of New Zealand. The river flows from the [[Ruahine Ranges]], through both the [[Manawatū Gorge]] and the city of [[Palmerston North]], and across the Manawatū Plains to the Tasman Sea at [[Foxton, New Zealand|Foxton]].
== Name == The river, along with the more northern [[Whanganui River]], gives its name to the [[Manawatū-Whanganui]] region. The name of the river was given by the [[tohunga]] Haupipi-a-Nanaia, a descendant of Haunui-a-paparangi. Haupipi-a-Nanaia or Hau, travelled down the west coast in pursuit of his wife Wairaka, who had eloped. When Hau reached what is now known as the Manawatū River, he is said to have stopped and clutched his chest, horrified at the prospect of crossing so mighty an expanse of water. Therefore the river's name comes from the Māori words ''manawa'' (heart) and ''tū'' (stand still). In this context, when said together, the interpretation is ‘heart standing still’ to represent how Hau felt when he first saw the river. However cross he did, and a few kilometres south of Paekākāriki, Hau overtook the fugitives and changed Wairaka into a rock.<ref>Reed, A.W. (1996) ''The Reed Dictionary of Māori Place Names, Te Papakupu Ingoa Wāhi Māori a Reed'' (3rd Ed) Reed Publishing: Auckland, New Zealand</ref>
==Geography== The Manawatū River has its headwaters northwest of [[Norsewood]] in the [[Tararua District]], on the eastern slopes of the [[Ruahine Range]] on the North Island of New Zealand. It flows initially eastward before turning south-west near [[Ormondville]], flowing {{convert|40|km|mi}} before turning north-west near [[Woodville, New Zealand|Woodville]]. At this point it enters the [[Manawatū Gorge]], between the Ruahine and [[Tararua Range]]s.{{sfnp|Knight|2014|p=20}} Beyond the gorge it joins with the [[Pohangina River]] at [[Ashhurst]] and turns south-west, flowing through the city of [[Palmerston North]]. At this stage the river is still flowing swiftly and carrying gravel from the mountains.
After [[Opiki]], it slows and has a lower gradient, [[meander]]ing over the [[Manawatū Plains]]; its bed at this point is mud and silty sand. In its meandering and frequent shifting of course it has created [[oxbow lake]]s, [[lagoon]]s, and [[swamp]]s. Sediment deposited along its course has created levees, higher than the surrounding plain; when the river is in flood it overflows these and creates wetlands.{{sfnp|Knight|2014|p=20}} The Manawatū reaches the [[Tasman Sea]] at [[Foxton Beach]], on the west coast of the North Island, creating the [[Manawatū Estuary]].{{sfnp|Knight|2014|p=21}}
Major tributaries of the river include the [[Mākākahi River|Mākākahi]], [[Mangahao River|Mangahao]], [[Pohangina River|Pohangina]] and [[Oroua River]]s. The Manawatū's total length is {{convert|180|km|mi}}, making it only the 12th-longest in the country, but at {{convert|102|m3/s|cuft/s}} it is one of New Zealand's greatest rivers in terms of flow, and second only to the [[Waikato River]] among North Island rivers.
=== Bridges === The river is crossed by 18 road bridges (not including the under-construction Parahaki Island Bridge), 3 rail bridges<ref>{{Cite web|title=New Zealand Topographic Map|url=https://www.topomap.co.nz/NZTopoMap?v=2&ll=-40.481084,175.234423&z=14|website=NZ Topo Map|language=en|access-date=2020-05-29}}</ref> and [[Palmerston North#Riverbank development|He Ara Kotahi]] walk/cycleway.<ref>{{Cite web|title=He Ara Kotahi|url=https://www.pncc.govt.nz/services/parks-venues-recreation/walks-and-walkways/he-ara-kotahi/|website=www.pncc.govt.nz|language=en|access-date=2020-05-29}}</ref> The lowest and longest, Whirokino Trestle and Manawatū River Bridge, carry [[State Highway 1 (New Zealand)#North Island (SH 1N) 2|SH1]] {{convert|1.1|km||abbr=on}} over the Moutoa Floodway and {{convert|180|m||abbr=on}} over the river. It replaced the 1938 and 1942 bridges<ref>{{Cite web|title=Whirokino Trestle Bridge replacement|url=https://www.nzta.govt.nz/projects/whirokino-trestle-and-manawatu-river-bridge/|date=2015|website=NZTA}}</ref> in February 2020, at a cost of $70m.<ref>{{Cite web|title=Opening of Whirokino Trestle and Manawatū River Bridge adds traffic to congested highway|url=https://www.rnz.co.nz/news/national/410905/opening-of-whirokino-trestle-and-manawatu-river-bridge-adds-traffic-to-congested-highway|date=2020-03-04|website=[[RNZ]] |language=en-nz|access-date=2020-05-29}}</ref>
The derelict [[Opiki Toll Bridge]] crosses the river and no longer has a floor. It is a [[Heritage New Zealand]] Category I historic place.<ref name=":1">{{Cite web |title=Tane Hemp Company Limited Suspension Bridge and Flaxmill Remains |url=https://www.heritage.org.nz/list-details/9619/Tane%20Hemp%20Company%20Limited%20Suspension%20Bridge%20and%20Flaxmill%20Remains |access-date=4 May 2025 |website=[[Heritage New Zealand]]}}</ref>
== Geology == The Manawatū is unique among New Zealand rivers in that it crosses a mountain range. The river has formed a "water gap" across the mountains because it is older than the Ruahine and [[Tararua Ranges]]. Most rivers arise from an already-existing range of mountains or hills, but beginning about 3 million years ago the central North Island mountain ranges began to uplift across the Manawatū's current course. Because it drained a large catchment, the river had sufficient flow to keep pace with and erode the rising mountains, eventually forming the Manawatū Gorge; other rivers were unable to and were diverted into the Manawatū instead.{{sfnp|Knight|2014|p=24}}
After exiting the Manawatū Gorge, the river carries rock and sediment down from the mountains. During glacial times, with the prevalence of ice, snow, and bare mountains, this erosion increases and forms a stony elevated terrace. During an interglacial, while the mountains are forested, gravel outwash is reduced and the river cuts down into the terrace, forming a gorge. This cycle has created four distinct terraces between the Manawatū Gorge and Palmerston North.{{sfnp|Knight|2014|p=20}}
The Manawatū Plain was seabed 5 to 6 million years ago, and as it was raised above water by the action of the Australian and Pacific Plates it buckled, forming five long and low ridges (or [[anticline]]s) parallel to the mountains, which impede the flow of the Manawatū, [[Rangitikei River|Rangitikei]], and Oroua Rivers, forcing them to flow southwest rather than directly into the Tasman Sea.{{sfnp|Knight|2014|p=20}}
== Vegetation == At the time of human arrival, the Manawatū Plains were covered with forest. Towards the foothills and the Manawatū Gorge grew [[Nothofagus solandri|black beech]], turning into [[Beilschmiedia tawa|tawa]] forest at lower altitudes. Along the plains and terraces the forest was mixed [[Podocarpaceae|podocarp]] and [[Podocarpus totara|tōtara]], changing to mixed tawa, [[Alectryon excelsus|tītoki]], and [[Melicytus ramiflorus|māhoe]] in the sand dunes.{{sfnp|Knight|2014|p=25}}
Across the flood plain of the Manawatū and on the low-lying land bordering the river, the predominant vegetation was semi-swamp forest, mostly [[Dacrycarpus dacrydioides|kahikatea]] and [[Laurelia novae-zelandiae|pukatea]].{{sfnp|Knight|2014|p=25}} Three major swamps bordered the Manawatū: Moutoa Swamp north of the river, towards the mouth, known as the "Great Swamp" in the 19th century; Makerua Swamp further inland, to the south of the Manawatū and north of the Tokomaru River, which covered 22000 acres; and Taonui Swamp on the north side of the river.{{sfnp|Knight|2014|p=48}} The main vegetation in the swamps was [[Phormium tenax|harakeke]] and [[Typha orientalis|raupō]]: harakeke in the drier parts, raupō in the wetter.{{sfnp|Knight|2014|p=150–151}}
The [[Manawatū Estuary|Manawatū river mouth and estuary]] was listed under the [[Ramsar Convention]] as a Wetland of International Importance in 2005.
== Flooding == The Manawatū River flooded in February 2004, displacing over 3000 people (primarily from [[Marton, New Zealand|Marton]] and [[Feilding]]) and damaging over 1000 Manawatū farms. The cost of the flood in terms of insurance payouts was NZ$122 million. Further damage was prevented by the opening of the Moutoa [[floodgate]]s, which intercept the river between [[Foxton, New Zealand|Foxton]] and [[Shannon, New Zealand|Shannon]].
==Water quality== In 2018 a case study on water quality in the [[Manawatū-Whanganui]] region was jointly commissioned by [https://www.horizons.govt.nz/ Horizons Regional Council] and the [[Ministry for the Environment (New Zealand)|Ministry for the Environment]], the study was conducted by [https://landwaterpeople.co.nz/ Land Water People (LWP)] and the results were reviewed by the [[National Institute of Water and Atmospheric Research|National Institute of Water and Atmospheric Research (NIWA)]] and [[Statistics New Zealand|StatsNZ]]. Results showed that water quality for [[sediment]] and [[Escherichia coli|''E. coli'']] had improved over the previous seven to ten years in the Manawatū-Whanganui region. The report found strong statistical evidence of a connection between regional scale water quality improvements and local scale interventions.<ref>{{cite web |last1=Snelder |first1=Ton |title=Assessment of recent reductions in E. coli and sediment in rivers of the Manawatū-Whanganui Region |url=https://www.manawaturiver.co.nz/2018/02/15/improved-water-quality-in-horizons-region-shows-more-rivers-more-suitable-for-swimming/ |publisher=Land Water People Ltd |access-date=22 November 2018}}</ref>
In 2006 [[Fonterra]] were criticised for an application to discharge {{convert|8500|m3|cuft}} of wastewater into the Manawatū River.<ref>{{cite press release | title = Forest & Bird calls on Fonterra to clean up its act on the Manawatu River | publisher = [[Royal Forest and Bird Protection Society of New Zealand]] | date = 9 August 2006 | url = http://www.forestandbird.org.nz/mediarelease/2006/0809_fonterramanawaturiver.asp | access-date = 13 March 2008 | archive-url = https://web.archive.org/web/20071019224420/http://www.forestandbird.org.nz/mediarelease/2006/0809_fonterramanawaturiver.asp | archive-date = 19 October 2007 | url-status = dead }}</ref> In 2009, the [[Cawthron Institute]] found that the river had the highest [[gross primary production]] (GPP) compared to 300 rivers and streams in the Western world.<ref>{{cite web|url=http://www.cawthron.org.nz/publication/science-reports/temporal-variability-ecosystem-metabolism-rivers-manawatu-whanganui-region-updated/|title=Ecosystem metabolism in the Manawatu River|last=Young|first=Roger|publisher=Cawthron Institute|access-date=15 May 2011}}</ref> High GPP rates are an indication of poor [[ecological health]] and can lead to various [[environmental issue]]s. In 2011, the Horizons Regional Council laid blame with the Palmerston North City Council for "considerable" and "sustained" breaches of one of its discharge consents, and some degree of non-compliance with two others.<ref>{{cite web |url=http://www.stuff.co.nz/national/5614096/Manawatu-River-pollution-blamed-on-council |title=Manawatu River pollution blamed on council |publisher=Fairfax NZ |access-date= 14 April 2012}}</ref> A report by the [[Ministry for the Environment (New Zealand)|Ministry for the Environment]] ranked 76 New Zealand sites for water clarity and ''[[Escherichia coli|E. coli]]'' levels. Using those measures, they found only four other New Zealand rivers rate worse than the Manawatū (the [[Waitara River|Waitara]], [[Whanganui River|Whanganui]], [[Waipā River|Waipā]] and [[Rangitīkei River|Rangitīkei]]).<ref>{{cite web |url=http://www.mfe.govt.nz/environmental-reporting/freshwater/river/league-table/clarity-ecoli.html |title=Recreational river water quality league table: water clarity and ''Escherichia coli'' bacteria levels |publisher=Ministry for the Environment |access-date=26 November 2009 |archive-url=https://web.archive.org/web/20100522092810/http://www.mfe.govt.nz/environmental-reporting/freshwater/river/league-table/clarity-ecoli.html |archive-date=22 May 2010 |url-status=dead }}</ref>
== References == {{Reflist|20em}}
==Sources== {{Refbegin}} *{{cite book|title=New Zealand's Rivers: An Environmental History|last=Knight |first=Catherine|publisher=Canterbury University Press|location=Christchurch|year=2016|isbn=978-1-927145-76-0}} *{{cite book|title=Ravaged Beauty: An Environmental History of the Manawatu|last=Knight |first=Catherine|publisher=Dunmore Press|location=Auckland|year=2014|isbn=978-1-927212-13-4}} {{Refend}}
==External links== {{commons category|Manawatu River}} * [https://web.archive.org/web/20050416222951/http://www.mfe.govt.nz/publications/ser/ser1997/html/chapter7.6.html State of New Zealand's Environment 1997 - Chapter 7: Nature of NZ's water environment [Ministry for the Environment]] * {{Cite news|url=http://www.stuff.co.nz/manawatu-standard/6467404/Manawatu-River-quality-not-worst|title=Manawatu River quality not worst|last=Galloway|first=Jill|date=2012-02-23|work=Manawatu Standard|access-date=2018-11-23}} * {{Cite news|url=http://www.stuff.co.nz/national/6611394/Manawatu-River-bad-but-not-the-worst|title=Manawatu River bad, but not the worst|last=Goodwin|first=Emma|date=2012-03-21|work=Manawatu Standard|access-date=2018-11-23}} {{Manawatu}}
{{DEFAULTSORT:Manawatū River}} [[Category:Rivers of Manawatū-Whanganui]] [[Category:Rivers of New Zealand]]