TAUPŌ CONTROL GATES

The Taupō Control Gates is a critical piece of infrastructure spanning the Waikato River at the northern entrance to Taupō town. Situated 1km downstream from the outlet of Lake Taupō, the structure serves both as a bridge for Tongariro Street and as a vital flow‑control facility for the Waikato Hydro System.

The concrete structure houses six control gates and a central boat lock channel. These gates regulate water released from Lake Taupō, supporting downstream hydroelectric generation and playing an essential role in managing high river flows across the hydro system.

Lake Taupō has a 3,300 km2 catchment which includes many streams and rivers. The largest inflows come from the Tongariro River and the Tongariro Power Development in the central North Island into Lake Taupō.

The gates help regulate the amount of water flowing out of the lake and down the Waikato River. Read more about Mercury’s operating range and Taupō lake levels here.

Originally designed and constructed in the 1940s, the gates have undergone several upgrades and refurbishments over their service life. Major refurbishment was completed on gates 4, 5 and 6 between 2010 and 2012. Continued maintenance and refurbishment are required to ensure the ongoing safety, reliability, and performance of the gates.

Recent works

As part of our ongoing maintenance programme, recent works include refurbishment of Gate 2 (completed in 2024-2025), followed by work on Gate 1 and 3 during 2026. Gates 3 was refurbished and reinstalled in April 2026, with Gate 1 planned for refurbishment in February-March 2027.

To safely complete this work, temporary overnight road closures were put in place on the Control Gates bridge on Tongariro Street on 13-14 April 2026. Traffic management was in place during these works, and pedestrian access was maintained with short delays during gate lifting. These works were scheduled during the night, outside of busy commuter times to minimise disruption.

Looking ahead

Mercury regularly reviews the Control Gates as part of our ongoing dam safety assurance programme. This allows us to confirm that the gates are operating reliably, while also helping inform long-term planning for the future.

At the same time, we are planning ahead to ensure the Control Gates continue to meet the needs of the Waikato Hydro System for decades to come.

We are undertaking technical assessments (such as engineering studies, modelling, environmental and construction investigations) to build a clearer understanding of the current structure and support future planning.

This work is at an early stage, and we will share more information as planning progresses.

How can I keep updated on the project?

You can contact the project team on mercurycontrolgates@mercury.co.nz
Learn more about Mercury’s hydro generation here.

For Waikato River Flows and Take Taupo Levels, ring 0800 820 082.