Talk:Whanganui River

Densely populated?
An early edit added the phrase "the area around the Whanganui was one of the most densely inhabited in the land", but gave no evidence. The Archaeology Map shows relatively sparse sites along the river and even fewer away from it. What is the evidence for dense population? Johnragla (talk) 07:41, 26 July 2020 (UTC)
 * Are we perhaps missing a word: it's the Whanganui River mouth that was densely inhabited, looking at the Archaeology map you linked to.- gadfium 08:23, 26 July 2020 (UTC)
 * Patea and many other river and harbour mouths seem to have equal or greater density of sites. Johnragla (talk) 08:28, 26 July 2020 (UTC)

Lahars
There is a vague mention on the page of a Lahar in the 1970's. This was removed and I undid the revision. It does appear there is some history of Lahars in the upper catchment of the Whanganui River (both the Whakapapa River and the Mangaturuturu River) see image here: https://www.gns.cri.nz/var/ezwebin_site/storage/images/media/images/ruapehu-figure-8/5889-1-eng-GB/Ruapehu-figure-8.jpg.

From limited research, it appears there was a lahar that flowed down the skifield and into the Whakapapa River in 1975. See:
 * https://teara.govt.nz/en/historic-volcanic-activity/page-6
 * https://www.gns.cri.nz/Home/Learning/Science-Topics/Volcanoes/New-Zealand-Volcanoes/Volcano-Geology-and-Hazards/Ruapehu-Geology
 * https://docs.niwa.co.nz/library/public/fer22.pdf

I don't have time to fix this a cite it all properly right now. IMO, there would ideally be a general mention of Lahar history on this page and maybe more detail on Lahars at Whakapapa River, Whakapapa skifield, and Mangaturuturu River.

I also note there is no dedicated page for Whakapapa Village which is in the potential Lahar runout zone. Seems strange that a populated place didn't have a dedicated page. Notable for the skifield, Chateau Tongariro, Tongariro Northern Circuit, and I also think it is the highest elevation populated place in NZ. ShakyIsles (talk) 01:22, 21 June 2021 (UTC)

Reduction of river level
As a result of the hydro electrification scheme of the tongariro in the 1950s, 50% of the water flowing into the river was diverted to flow to the Waikato River. Such a dramatic change to the water flow would be appropriate to include in the article. &mdash; F red  114  22:39, 31 January 2017 (UTC)


 * Hello Fred. I saw the info you added to the article and I have removed it. No doubt a mention of the events should be included, but what you contributed is not accurate. You wrote
 * "In 1960 the headwaters of the Whanganui River were diverted into Lake Rotoaira, then on into Lake Taupo and the Waikato catchment for hydroelectric power generation."
 * The headwaters were not diverted. Only part of them were, witness the fifty percent of the normal flow that continued through Taumarunui. (And of course the numerous tributaries entering the river below that town meant that flows lower down were not as serious as some people believed).
 * Also, references would be needed for any such information. Cheers. Moriori (talk) 23:19, 31 January 2017 (UTC)


 * This is covered and referenced on both the Tongariro Power Scheme (see Western Diversion section) and the Whakapapa River pages. Worth adding something here as well. ShakyIsles (talk) 19:54, 1 March 2023 (UTC)