Last Sunday TRM Daily Report repeated the complaints from concerned inmates who were trapped by the suddenly rising Tongariro River. Several other anglers also phoned in asking TRM to get stuck into Genesis over their “release” (?) fearing someone could get drowned one day?
We did this by repeating previous reports of flooding which had been denied by Genesis – the power company that controls the flow below the hydro dams on the Tongariro River.
Genesis have responded again advising “that the flow peaks observed on the Tongariro River in Turangi were as a result of a natural fresh event and not Power Scheme operations.” see below. The flow graph illustrates the sudden increase in flow on 8 October.
As discussed this morning, please find below a summary of the flow conditions last Wednesday morning on the Tongariro River. I would like to emphasise that the flow peaks observed on the Tongariro River in Turangi were as a result of a natural fresh event and not Power Scheme operations.
41mm of rainfall was measured at the Ruatahuna raingauge above the Whitikau catchment between 01:00 and 09:00 on the 8 November. The swollen Whitikau caused an initial peak of 60 cumecs on the Tongariro River in Turangi at 09:30. Over the same period, 54.5mm of rain was recorded at Waipakihi. The Tongariro River at Waipakihi peaked at 09:00 as a result of this rainfall. This flood peak was observed at Turangi at 12:20, having taken three hours and twenty minutes to reach Turangi from Waipakihi and being the second fresh peak on the Tongariro River in Turangi of the day. The two flow peaks observed were as result of rainfall in the Whitikau and Waipakihi catchments of the Tongariro taking different times to reach Turangi.
There were no significant changes in flow through the Rangipo Power Station (above Poutu Intake) over this period and the Poutu Canal Diversion (which takes water from the Tongariro and transports it to Lake Rotoaira) was not closed as a result of this flood. Genesis Energy has limited ability to control flood flows on the Tongariro River and has a maximum consented water take of 80 cumecs in the Poutu Canal.
Rainfall events like the one seen last Wednesday highlight the peaky nature of the Tongariro River, and the varied hydrologic responses from different catchments. For this reason, river users should look at weather forecasts and rainfall graphs to assess risks before entering the river. Genesis provides hydrology data from around the Tongariro Power Scheme to the public through the Genesis website (https://www.genesisenergy.co.nz/rivers-lakes-rainfall) as well as providing a flow phone (07 3868113).
Genesis Energy takes stakeholders safety concerns very seriously. I hope the information provided is useful, please don’t hesitate to contact me with any queries in future.
Chris Ormandy | Environmental Lead – North Island
Genesis Energy Ltd | Tokaanu Power Station | Private Bag 36 | Turangi 3353
M. 021 399 215 DDI. 07 384 7209 ”
TRM Report last Sunday:
Every year this happens. It is sad that we have to repeat the same story again.
Anglers complain to us that it is inevitable – that someone will get drowned one day due to neglect by Genesis – the power company that control the flows on the Tongariro River. They have been saying that for the last 12 years or so. The last time TRM reported on it in 2016, the unfortunate angler was also the Editor of Fishing & Outdoors newspaper and who is now President of NZFFA (New Zealand Federation of Fresh Water Anglers) – but they still have not learnt that anglers lives are at risk?
After a wet night on Wednesday the TRM team from Australia were keen to get out on the river. The Tongariro river level was up a bit following the rain and retreating – mild temperatures after rain, no wind, still very fishable, good colour, so all added up to perfect conditions. On our recommendations, they crossed over the bypass on to the island to fish the run at what is known as the Island Pool. This is within easy walking distance of TRM and provides several options.
These anglers from a Melbourne fishing club – Mornington Peninsula – are sensible mature experienced river anglers – so they would not panic over a minor fluctuation in river flow. But this was something else. They have stayed here before but are not that familiar with such huge Tongariro fluctuations. They are all retired and at a guess would be in their late 60’s or early 70’s, so they are not as nimble or fit as they once were. They are certainly not strong waders. So TRM choose their pools carefully.
Then after about half an hour after they crossed over to the island, without warning the river rapidly turns chocolate brown so they tried to return. But by then the crossing was flooded and flowing very fast. Fortunately they only just managed to wade across, and were very relieved to get back before the levels increased further. They thought they were going to be trapped there. They also met other anglers who just managed to wade back at the lower Judges Pool end of the island who were similarly alarmed at how this could be allowed to happen…