A TRM fisho – who has a very long association (or love affair ?) with Lake O – contacted Genesis as follows:
I am interested to learn the reason for cut off of flow into lake Otamangakau, Turangi. I fish the lake regularly and plan to visit again in March/April. Was wondering if flow would be restored or is it just rain dependent. I have heard conflicting accounts as to the reason for no flow. Kind regards
Reply from Genesis:
Every year Genesis has to release water to meet downstream minimum flow requirements below Taumarunui on the Whanganui River. The reduced flow is a usual result of these consent conditions every year, the amount and duration fully depends on how much it rains in any year. This year a planned tunnel outage occurs at the same time.
The Tunnel outage also means that we are now bringing water into Lake Otamangakau from the Whanganui Intake instead of the Whanganui Tunnel. The flows have been lower than usual due to the extended dry spell of weather but we expect those to pick up this weekend with the forecast rainfall.
The outage is due to be completed on 12 April so around that time the flows will increase only if the downstream minimum flow requirements are met.
Below is an email that has been sent to some of the known stakeholders that will be of interest to you.
“Genesis Energy will be undertaking maintenance on the Whakapapa-Whanganui Tunnel during which time no water will be diverted into the tunnel. As a result, flows will be higher on the Whakapapa, Mangatepopo, Okupata, Tawhitikuri and Taurewa Rivers. Note: This includes flows at the Okupata Caves.
The work is planned from:
* Thursday 7th February until Friday 12th April 2019
Whilst the works are planned to be finished by Friday 12th April, they may continue after this date for a short period if maintenance is required. Please be aware that the flows are subject to natural fluctuation (e.g. weather events). Please feel free to share this information with other river users (i.e. via website or social media pages).
If you have any questions or require further information, please contact Chris Ormandy on 07 384 7209 or firstname.lastname@example.org.
Visit https://www.genesisenergy.co.nz/tongariro-riverflow-release for flow information.”