flowing water rapids


Water is vital to our business as it is essential to our 100% renewable generation sources – hydro and geothermal. We have a long heritage with the Waikato River dating back nearly a century as it is home to our eight hydro dams which make up the Waikato hydro system. This drives our strong commitment to the environmental health and well-being of the river for all.
River dam


Freshwater: New Zealand's Taonga (treasure) – a swim in clean, fresh water. A day with friends or family picnicking by a river. These are precious things that Kiwis rightly value. Our rivers and lakes hold a special place in the hearts of all New Zealanders, particularly our tangata whenua (people). Water sustains all life, but is often taken for granted. Freshwater access and quality are sustainability challenges globally and here in New Zealand.

It's vital to our precious ecosystems, the economy, our country’s drinking water supply, and a wide range of recreational activities including fishing, swimming and boating. It is also integral to New Zealand’s renewable energy advantage – without it, the production of electricity through hydro generation could not occur.

Our geothermal generation also relies on water from deep within the ground. Combined, hydro and geothermal energy sources make up around 75% of New Zealand’s total electricity generation.
For all of these reasons, freshwater is one of our most valuable natural assets. At Mercury the responsible management of our waterways is not only a part of what we do – it is part of who we are.

The equivalent of more than 500,000 New Zealand homes benefit from the electricity generated by Mercury’s nine Waikato River hydro stations, known collectively as the Waikato Hydro System.
Across our hydro operations, Mercury harnesses the raw power of water for the generation of electricity as it flows down the river, available to the environment and other uses. We think that’s wonderful.
So we’re committed to understanding, managing and minimising any impacts our operations have on water, along with looking at the ways we can continue to innovate and improve the efficiencies of capturing the raw energy from the flow of water.
Our strong and consistent record of doing the right thing (some would call it ‘operational compliance’ - but it’s that and more) is supported by a range of environmental management activities.

These include:
// Studying water presence and flow (hydrological analysis).
// Understanding the ground that water travels over and through (geomorphological studies).
// Observing impacts (ecological monitoring).
We also involve ourselves in a range of long-term projects to improve the natural environments within which our hydro stations are located.
More information on this is set out in our Corporate Governance Statement.


Mercury has a deep respect for the close links that iwi have with water, including the tupuna awa relationship held by many Waikato River iwi. We acknowledge and respect Te Ture Whaimana o Te Awa o Waikato (the vision and strategy for the Waikato River).

We work closely with iwi, hapu and marae identifying how we can best manage freshwater.

In the spirit of partnership, we look for mutual mana-enhancing opportunities with the people and organisations that make up the river iwi. Mercury supports a range of programmes, including social enterprises, educational initiatives, environmental and ecological restoration projects along with a number of Māori cultural initiatives.
waikato river sign


Through our long-standing partnership with the Waikato Catchment Ecological Enhancement Trust (WCEET), we’re helping to protect and enhance the ecology and biodiversity of Lake Taupo and the Waikato River.

Over the past 13 years, WCEET in partnership with Mercury, has worked on hundreds of projects to the value of $5.5m. Learn more about the WCEET.


At Mercury we make sure we’re part of the conversation.
We actively contribute to water policy and reform at both a regional and national level, and regularly participate in discussions with Government and local authorities on freshwater management. This includes:

// The National Land and Water Forum.
// Ministry for the Environment’s consultations on national water policy reform (including the National Policy. Statement Freshwater Management and the Resource Management Act).
// Waikato Regional Council’s Healthy Rivers / Wai Ora: Plan Change.
// Waikato Regional Council’s “Let’s Talk Water”/Water Strategy.
// Waikato River Authority’s Waikato River Restoration Strategy.
// Restoration and rehabilitation projects in partnership with the Waikato River Authority.