Mangapu River

{{Use dmy dates|date=July 2019}}

{{Use New Zealand English|date=July 2019}}

{{Infobox river

| name = Mangapu River

| image =File:Mangapu River from Pehitawa bridge.jpg

| image_size =

| image_caption =Mangapu River from Pehitawa bridge

| source1_location =

| mouth_location = Waipā River

| subdivision_type1 = Country

| subdivision_name1 = New Zealand

| length = {{convert|48|km|mi|abbr=on}}

| source1_elevation =

| mouth_elevation =

| discharge1_avg =

| basin_size =

}}

The Mangapu River is a river of the Waikato region of New Zealand's North Island. It has its sources in numerous streams which flow generally northwards from the King Country south of Te Kūiti, the longest of which is the Mangaokewa Stream. These streams join to form the Mangapu close to Te Kuiti, and from here the river flows north, passing close to the east of Waitomo Caves, where the Mangapu caves have the largest entrance in the North Island{{Cite web|url=https://www.waikatoregion.govt.nz/assets/WRC/Council/Policy-and-Plans/HR/S32/Part-A/Department-of-Conservation-2014.-Conservation-Management-Strategy-Waikato-20142024-Volume-I-Operative-29-September-2014.-New-Zealand.pdf|title=CONSERVATION MANAGEMENT STRATEGY WAIKATO 2014–2024| volume=I|date=29 September 2014|publisher=Department of Conservation}} (about {{Convert|100|m|ft|abbr=on}} long and {{Convert|90|m|ft|abbr=on}} deep),{{Cite web|url=http://bts.nzpcn.org.nz/bts_pdf/Well_1987_43__3-6.pdf|title=The Flora of the Lost World Cavern, Mangapu Caves System}} before flowing into the Waipā River at Ōtorohanga.{{LINZ|39558|Mangapu River|2010-04-21}}

The New Zealand Ministry for Culture and Heritage gives a translation of "double stream" for Mangapū.{{Cite web|url=https://nzhistory.govt.nz/culture/maori-language-week/1000-maori-place-names|title=1000 Māori place names|publisher=New Zealand Ministry for Culture and Heritage|date=6 August 2019}}

SH3 crosses the river on a {{Convert|111|m|ft|abbr=on}} bridge near Ōtorohanga built in 1966{{Cite web|url=http://his.aucklandmotorways.net/PDFs//WAIKATO/00006_469_WAIKATO_PSMC006_003_6.pdf|archive-url=https://web.archive.org/web/20170205100023/http://his.aucklandmotorways.net/PDFs//WAIKATO/00006_469_WAIKATO_PSMC006_003_6.pdf|url-status=dead|archive-date=5 February 2017|title=Highway Information sheet 003-0057}} and near Hangatiki on a {{Convert|41|m|ft|abbr=on}} concrete bridge built in 1977.{{Cite web|url=http://his.aucklandmotorways.net/PDFs//WAIKATO/00007_470_WAIKATO_PSMC006_003_7.pdf|title=Highway Information sheet 003-0063|archive-url=https://web.archive.org/web/20170205095832/http://his.aucklandmotorways.net/PDFs//WAIKATO/00007_470_WAIKATO_PSMC006_003_7.pdf|url-status=dead|archive-date=2017-02-05}} The railway follows the east bank for about {{Convert|6|km|mi|abbr=on}}, crossing only small tributaries,{{Cite web|url=http://www.topomap.co.nz/NZTopoMap/nz56817/Mangapu-River/Waikato|title=Mangapu River, Waikato - NZ Topo Map|website=NZ Topo Map|language=en|access-date=2017-02-04}} though it did suffer from flooding, for example in 1905.{{Cite web|url=http://www.aucklandcity.govt.nz/dbtw-wpd/exec/dbtwpub.dll?BU=http://www.aucklandcity.govt.nz/dbtw-wpd/HeritageImages/index.htm&AC=QBE_QUERY&TN=heritageimages&QF0=ID&NP=2&MR=5&RF=HIORecordSearch&QI0==%22AWNS-19051109-15-6%22|title=FLOOD WATERS RUNNING THROUGH A BLOCK CUTTING ON THE RAILWAY BETWEEN HANGATIKI AND OTOROHANGA|date=9 November 1905|website=www.aucklandcity.govt.nz|access-date=2017-02-04}}

The river at Ōtorohanga is classed as being in the worst 25% of similar sites as regards all measured pollutants,{{Cite web|url=https://www.lawa.org.nz/explore-data/waikato-region/river-quality/waikato-river/mangapu-river-at-otorohanga/|title=Land, Air, Water Aotearoa - Mangapu River at Otorohanga|website=www.lawa.org.nz|access-date=2017-02-04}} though some attempts are being made at restoration.{{Cite web|url=http://www.makearipple.co.nz/Action-groups/ripples/Mangapu-River-Riparian-Restoration/|title=The Ripple Effect|website=www.makearipple.co.nz|language=en-NZ|access-date=2017-02-04}}