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Our Environment


Over recent years, the course of the Harper River near TrustPower’s Harper intake gates has changed, raising the water velocity. This has made it more difficult for trout on their winter migration to negotiate their way upstream past the gates.

We’re always looking for ways to create a positive impact, so in consultation with Fish and Game, we recently installed a rock weir downstream from the gates, creating a two-staged approach for the trout. The weir reduces the height of the step through the gates. It also creates a backwater, where the trout can rest before making the jump to pass through the gates.

Initial monitoring by Fish and Game staff indicates that the weir has successfully enhanced the efficient passage of fish. This will be confirmed by further monitoring during trout migration in 2012.


TrustPower owns and operates 22 renewable generation schemes: 19 hydroelectric; plus two wind farms in New Zealand and one in Australia. To achieve our vision, the continued successful operation of all our generation assets is essential. That means we need secure access to the natural resources that power them.

To ensure this access, in New Zealand we hold consents issued under the Resource Management Act 1991 (RMA). We now hold 550 consents, for example to cover: the minimum required flow below a scheme to maintain downstream river values; how quickly a hydroelectric power station can turn on and off; and how often this can occur daily. Our consents also specify ongoing monitoring requirements to ensure schemes do not negatively impact the environment.

Our consents generally last for 35 years, the maximum term allowed under the RMA. When consents expire, we must apply to renew them. This is known as re-consenting and involves a two to four-year process, with extensive assessments of ecology, cultural impacts, erosion, hydrology, recreation, landscape, and more, similar to the process of consenting a new asset.

The effort put into the assessments ensures that every re-consenting application details the environmental effects, and can show that those effects are acceptable under the RMA. If any adverse effects are identified, measures to address them are explored, and incorporated into the application. The application is lodged and a hearing process initiated. The local council 
hears evidence for and against the scheme, and a decision is released. This decision can be appealed to the Environment Court.

In the re-consenting process, we take the opportunity to make any appropriate enhancements to schemes. One example is Patea, where we already had consent to access lower lake levels. The re-consenting led to an extension to the length of time we could access the lower levels, thereby providing new flexibility to meet future market demands. We often start the groundwork for re-consenting years before the process itself, paying close attention to district and regional plans, so rules are not developed that could hinder the current or future operation of assets.

As at April 2012, we are re-consenting the Matahina and McKay’s/Kaniere hydroelectric power stations. Once these are complete we will not require any further re-consenting until 2026.

We have also successfully gained consents for four significant future opportunities: Mahinerangi wind farm (initial stage constructed); Kaiwera Downs wind farm; Wairau hydroelectric power scheme; and Arnold hydroelectric power scheme. In addition we have gained consents for a number of smaller projects, and altered some conditions to optimise existing schemes. Examples include: consenting the Deep Stream hydroelectric power scheme near our Waipori scheme; consenting Highbank pumping station in association with the Highbank scheme; removing flow constraints on the Wheao/Flaxy scheme; and gaining use of greater lake range at one of the Kaimai scheme lakes.


At each of our generation schemes, our goal is to minimise potential adverse environmental impacts and, where practical, maximise positive environmental effects. Due to the number and geographic distribution of our generation schemes, we have a direct inter-relationship with many aspects of the environment.

TrustPower has a number of Environmental Polices which aim to achieve our goal. Further, our Environmental Management System identifies a series of objectives and actions to ensure we can meet our responsibilities as defined by the Environmental Policies. Objectives include, but are not limited to: complying with all environmental legislation; accurately reporting, monitoring and minimising all non-compliance events; implementing inclusive and flexible consultation programmes; improving our resource use and efficiency; ensuring all staff have appropriate environmental training to perform their roles; and reducing solid waste generated from our operations.

TrustPower not only seeks to monitor and mitigate adverse environmental effects resulting from operation of existing schemes, but also seeks to avoid creating adverse environmental effects from any proposed scheme. This is achieved by developing robust Assessment of Environmental Effects (AEE) reports, and by effective consultation with iwi and key stakeholders with any application for resource consent.

Most of our hydro schemes operate from lakes, with the rest being run-of-river schemes. Over 80% of total storage is in the five largest lakes: Matahina, Patea, Cobb, Coleridge and Waipori. These lakes have an approximate storage of 2.8 billion cubic metres and cover a combined area of approximately 6,828 hectares. In an average year, approximately 39.5 billion litres of water pass through the five schemes and into existing natural waterways.

Each scheme operates under a resource consent. These consents contain conditions that were established following an extensive consultative and regulatory review process. TrustPower’s key measure of environmental sustainability is compliance with the consent conditions.


With our 550 resource consents, we have 3,850 consent conditions that we must comply with. The six years to March 2011 saw the issuing of 231 new consents and 2,444 new consent conditions, due to new generation projects and re-consenting of existing schemes.

We undertake annual reviews of our compliance record and monitoring methods. Where any trends and areas for improvements are identified, we implement appropriate procedures to address them. Non-compliance events have been reduced from 18 in 2006/2007; to ten in 2011/2012. None of the events were determined as significant by the relevant regional council. One event was considered more than minor, however no significant effects were recorded.

In 2012 we initiated training workshops on compliance and management of hazardous substances. This training has proved very successful in raising awareness of our responsibilities for compliance and management of hazardous substances.


The term ‘contaminant release’ refers to the uncontrolled or accidental release of a hazardous substance or contaminant. No contaminant releases occurred in the 2012 year.


Over the past year, we have initiated a number of annual stakeholder meetings to discuss operations on a scheme-by-scheme basis. The primary aim is to develop enduring relationships with those who use the resources we rely on. We invite stakeholders, and discuss the year’s compliance record, any issues, and opportunities to work together. The meetings have proved very rewarding, and have opened up opportunities for stakeholders to discuss areas around the schemes that are beyond our influence, such as road upgrades and rubbish collection at recreational sites. The calendar of meetings will be expanded in the coming year.

Environment Graphs