Taupo’s Differences

Home of New Zealand’s largest lake – Taupō-nui-a-Tia, and largest source of freshwater (61,300 hectares).  Home to the start of New Zealand’s largest river – the Waikato Awa. Adjacent to the North Island largest mountain group in the Tongariro National Park.  Taupo ecological district is a basin dominated by Lake Taupo, occupying one quarter of the district, and edged by high mountain ranges draining down to the lake. 

 The Tongariro river fills Lake Taupō from the south from the mountain ranges of the National Park.Bounded to the east by the Kaimanawa, Kaweka and Tarawera Ranges.  Bounded to the west by the Pureora forest and Hauhungaroa Ranges.  The Taupō District is a very special place. 

Lake Taupo is a caldera volcano - a volcano that has collapsed into itself, often filling with water to form a lake. Lake Taupo has had at least two separate collapses.  It can be termed a ‘supervolcano’ and is the most frequently active and productive rhyolite caldera in the world. (Source: GNS Taupō Volcano) 

Yellow-brown soils formed from volcanic ash have developed on Taupo pumice over most of the area. The soil depth varies with topography, with soils often shallow particularly on steeper slopes.  The climate is the most continental-like in the North Island, with warm, often dry summers and cool winters. (Source: WRC Planting Guide) 

The topography is rolling to locally broken, mostly within the altitude range of 300 to 600 metres, with high points of Mt Tauhara (1091 metres) near Taupo township, and the north-west faces of the Kaimanawa Ranges (1300 to 1500 metres). The current land cover is mostly native forest on the steep ranges to the east and west, with the lower slopes in farmland to the north-west and plantation forestry to the south-east. (Source: WRC Planting Guide) .

The Wairakei and Tauhara Geothermal System dominate the northern Taupō area.   

Wairakei Geothermal Field is New Zealand’s oldest and largest (by electrical generation). The field covers between 20 and 25Km2 and lies 8 km north of Taupo along State Highway 1.  Over 290 wells have been drilled in the field, including 148 production and injection wells. Currently there are 73 producing and 19 injection wells.  The deepest feed is 2,880m. The hottest recorded temperature is 272 degrees celsius. 

Prior to development, Wairakei contained geysers, hot springs, and sinter terraces scattered along “Geyser Valley.”  In response to 60 years of production, the total pressure drawdown in the main reservoir is 26 bar.g. Fluid temperatures in the outflow regions have declined 20 degrees celsius. Shallow aquifer temperatures have declined up to 100 degrees celsius. 

The Wairakei Power Station is the world’s second geothermal power station, and the first to utilise flash steam from geothermal water as an energy source.  In addition to the power stations, over the years the operator has configured Wairakei to provide direct heat to customers including the Tourist Park Hotel (1958), a prawn farm (1988), and tourist operator Wairakei Terraces (2002). 

Wairakei provides consistent and reliable electricity. Annual power production from the initial A&B station remained remarkably steady for over 30 years. Over the 2018 financial year, the Field generated 2,770 GWh with an aggregate availability of over 95%. 

The Tauhara Geothermal Field lies along the eastern boundary of Taupō township (Waikato Region), at the northern end of Lake Taupō.  The Tauhara reservoir is liquid dominated with downhole temperatures ranging from 240 to 290 degrees celcius. The resource size is currently permitted at 250 MWe (Mega Watts). 

Contact Energy operates the field, generating electricity for the New Zealand power grid and supplying two phase fluid for industrial direct use. In addition, individual homeowners and businesses tap a shallow, hot-water reservoir for heating their homes and establishments. 

Tauhara’s significant Geothermal Features include geothermally influenced aquatic habitat (Onekeneke Stream), microclimates, hydrothermal eruption craters, hot springs, mud pools, steaming ground, and sinters. 

Contact Energy holds permits (consents) that allow the current construction of two new power stations. Tauhara I, located in the Tauhara East Sector, will be a Fuji 174 MWe, triple flash, condensing steam turbine due for completion in 2024. Te Huka unit 3, located in the Tauhara Central Sector, is a 50 MWe Ormat binary plant scheduled for commercial operation in 2024. 

The Tongariro Power Scheme is a 360 MW hydroelectricity scheme in the central North Island of New Zealand.  The scheme diverts water from tributaries of the Rangitikei, Whangaehu, Whanganui, and Tongariro rivers. These rivers drain a 2,600-square-kilometre (1,000 sq mi) area including Ruapehu, Ngauruhoe, Tongariro and the western Kaimanawa Ranges. The water diverted from these rivers is sent through canals and tunnels to generate electricity at three hydro power stations, Rangipo (120 MW), Tokaanu (240 MW) and Mangaio (2 MW). The water is then discharged into Lake Taupō where it adds to the water storage in the lake and enables additional electricity generation in the succession of power stations down the Waikato River. 

The scheme generates approximately 1350 GWh of electricity annually and contributes 4 percent of New Zealand's electricity generation. It is currently operated by electricity generation company Genesis Energy. 

Mercury hydro stations on the Waikato River were constructed from the late 1920s to the 1970s and have worked hard to keep the country powered.  The nine hydro plants along the Waikato River to produce about 10% of New Zealand’s electricity.  The great thing about hydro generation is that it can be increased or decreased quickly to meet peak demand for electricity. Mercury hydro system is the largest peaker in the North Island. 

Water quality is important for sustaining the freshwater plant and animals that live in Lake Taupō. Clear ‘bug-free’ water enhances the value of Lake Taupō as a safe place for swimming and other recreational activities. Also, the knowledge that the lake’s water quality is excellent is important to many people for aesthetic, cultural and spiritual reasons. Lake Taupō has become a symbol of near-pristine environmental conditions and is seen as a national treasure. 

Lake Taupō is an oligotrophic lake. This means it has low concentrations of nutrients and so biological productivity is relatively low. Plants, such as algae, require nitrogen and phosphorus to grow. Low nutrient levels in the lake mean that the amount of microscopic algae the lake can support is low. This in turn means the water is particularly clear and blue, and dissolved oxygen levels are not seriously depleted (through decaying plant matter). 

Lake Taupō was preserved in a near-pristine state and became a world-leading example of freshwater public policy success. The lake was saved by decision-makers, iwi, farmers, and landowners who chose to prioritise freshwater health for people and the planet. 

As part of He Ahi’s investigation into the land we consulted with many environmental experts. Kahu Environmental reported that the wetland at the neighbouring site is a natural inland wetland which is feed by a large catchment area that includes the He Ahi site. 

Kahu determined that He Tipu wetlands covers an area of around 2.24ha.  Historical records indicate that this is much smaller than its original size of around 5.16ha. This indicates that development in the area has diverted runoff away from the wetland.  

Evaluation of Indigenous biodiversity within the wetlands shows that areas populated with native plant species has retained a healthier ecosystem. Current habit would suit animals such as pūkeko and mallard ducks. In its current state the wetland is not large enough to support further species like pūweto. 

A multistage restoration plan has been outlined for the protection of the wetlands. Work will be done to secure water retention in the wetlands and replace invasive species with native. As part of He Ahi’s SMP, swales and retention ponds will be used to filter runoff off before allowing discharge into the He Tipu wetlands. This is important in ensuring that the wetland does not dry out. 

SMP’s are essential to any development. It is the responsibility of the developer to mitigate any disruption to the natural stormwater flow whenever we excavate and develop land. Without an effective SMP we can seriously disrupt the local ecosystem.  

Whenever water flows across the land it carries all sorts of debris that eventually discharge into sewers, rivers and lakes. SMP’s are essential in managing the risk of any soil and pollutants collected in the runoff.  

Poor Stormwater management can cause pollution, erosion, flooding and muddiness.  All of these aspects will disrupt the environment and likely cause infrastructure damage. 

He Ahi and our civil engineer at Strata have put an enormous effort into developing a SMP that best suits the environment. This process has taken countless hours, and we are proud of the works proposed to not only manage the stormwater but add to the local ecosystem. 

He Ahi is a Te Pae o Waimihia project who’s mission it is to support the growth of the hapū.  
Supporting local businesses is an obvious way to ensure the economic stability of the Taupō region. Throughout this project it has become clear that although Taupō sits in a central location the availability of services and products is limited and often shipped from other regions. 

Where possible He Ahi will engage with local providers.  As we move past the consent process and into the development stage this will become a big part of our focus. If you think your business has something to offer the development, please email us at kiaora@heahi.co.nz.