Hydropower in New Zealand
Hydropower is now one of New Zealand’s most important sources of energy, not only because of its major contribution to the energy sector, but also because of its non-carbon renewable status. Sourcing renewable energy is as important as ever, as fossil fuel and climate change become major threats to energy security. This page aims to assess the current state of hydropower in New Zealand. The history (both constructional and political) of New Zealand’s hydropower since the late 19th century has been reflected upon, and current and future trends that have been explored. Renewable energy generation in New Zealand was 77% of its total share in 2011, one of the highest levels of renewable energy generation in the OECD <ref name="MED">MED (Ministry of Economic Development), 2012. New Zealand Energy Data File. 2011 Calendar Year Edition. Available at http://www.med.govt.nz/sectors-industries/energy/pdf-docs-library/energy-data-and-modelling/publications/energy-data-file/energydatafile-2011.pdf (last accessed 01/10/13) </ref>. Hydropower accounted for 70% of this renewable electricity resulting in it being one of the highest energy sources in the New Zealand second only to oil, predominantly used in transport <ref name= "MED"/>. The environmental, economical, social and cultural impacts have been outlined, using environmental indicators to assess the performance of New Zealand’s hydropower schemes. An international case study (the Three Gorges Dam, China) has been included to place New Zealand’s hydropower industry in a global context. Recommendations have been made for future hydropower management and development in the future, based on the environmental indicator information available.
History of Hydropower in New Zealand
Early History of Hydropower and the 'Big Dam' era
Hydroelectricity has been a significant contributor to the New Zealand energy sector for over 100 years. A mountainous landscape in conjunction with high rainfall (particularly in the South Island) provides many opportunities for hydroelectricity generation in New Zealand <ref name= "Wright"> Wright, J. (2012) ‘Hydroelectricity or wild rivers? Climate change versus natural heritage’, Wellington: Parliamentary Commissioner for the Environment </ref>. Small hydropower plants existed in the 1880’s and early 1890’s mostly for gold dredging, dairy factories and freezing works. Some local authorities ran hydropower operations, such as the Reefton township, but most were operated independently <ref name= "Te Ara"> Te Ara Encyclopedia of New Zealand (2012) Hydroelectricity (online), available: http://www.teara.govt.nz/en/hydroelectricity (accessed 23 September 2013)</ref>. In 1896 it became compulsory to gain government permission for personal hydropower systems, and hydroelectricity became more of a state governed entity <ref name= "MoED"> Energy Information and Modelling Group (2012) ‘New Zealand Energy Data File’, ISSN 1177-6684, Wellington: Ministry of Economic Development </ref>. The Waipori (to power Dunedin) and Coleridge (to power Christchurch) schemes were established in 1903 and 1914 respectively, and hydropower has dominated the electricity sector since <ref name= "Te Ara"/>. The ‘think big’ era of the post WWII twentieth century saw the development of much larger hydropower schemes. The New Zealand government looked to capitalise on the opportunity to expand the hydropower industry, as well as to create employment in construction <ref name= "Wright"/>. New Zealand now has 5 major hydroelectricity schemes; Manapouri, Clutha and Waitaki (in the South Island) and Tongariro and Waikato (in the North Island), as well as numerous other smaller dams throughout the country.
History of Protest
As hydropower schemes become bigger and more prevalent in New Zealand, there is growing concern over their environmental impact <ref name= "Wright"/>. An example of this opposition was the ‘Save Manapouri’ campaign in the 1950’s, in opposition of the raising of Lake Manapouri by the construction of a dam. The primary concerns were the loss of animal and plant species, as well as beaches and islands. People throughout the country opposed the dam, and a compromise was able to be reached with an underwater scheme instead of a raised lake <ref> Peat, N. (1994) Manapouri saved! : New Zealand's first great conservation success story : integrating nature conservation with hydro-electric development of Lakes Manapouri and Te Anau, Fiordland National Park, Dunedin: Longacre Press. </ref>. Other notable oppositional campaigns were run against the Clyde and Ohakuri dams. There is now significant opposition to most modern dam proposals from locals, environmentalists, recreational river users, and tourism vendors <ref name= "Te Ara"/>. Rivers in their natural state are scarce in New Zealand, and are highly valued for their recreational and amenity values. They have a significant role in the history and culture of New Zealand <ref name= "Wright"/>. The ‘not in my backyard’ attitude definitely applies to most New Zealanders, who support the production of renewable energy in New Zealand, but do not want large scale dams to damage the amenity of their local landscapes. Controversy is only set to increase as renewable energy becomes more preferential; while the amenity value of New Zealand’s natural rivers becomes protected more fiercely.
New Zealand Hydroelectricity on the World Stage
In order to perceive the state of New Zealand’s hydroelectricity industry, it must be compared to international examples to gauge its performance in a global context.
Three Gorges Dam, China
The Three Gorges dam in the Yangtze river in the Hubei province in China is the largest capacity hydropower scheme in the world. The dam is 2309m in length and is a concrete gravity dam, with two power stations on either side. It has a capacity of 22,500 MW <ref> China, (1996) ‘The Three Gorges Project: A Brief Introduction’, Official government fact sheet, Washington, D.C., Chinese Embassy.
</ref>. While this dam has obviously provided massive renewable energy production along with increased shipping capacity and flood prevention, it has had significant adverse environmental effects. The dam has resulted in the displacement of 1.2 million people <ref> Gleick, P. H. (2009) The World’s Water 2008-2009, Washington: Island Press.</ref>. There is also concern of threat to species in the area (with 27% of China’s endangered fish species existing in the basin) by habitat fragmentation, downstream flood risk due to a lack of silt and an increased seismic pressure on local faults <ref> Wu, J., Huang, J., Han, X., Gao, X., He, F., Jiang, M., Jiang, M., Primack, R. B. and Shen, Z. (2004) ‘The Three Gorges Dam: An Ecological Perspective’, Frontiers in Ecology and the Environment, 2(5), 241-248.</ref>.
The dam is still relatively young, having only been fully completed in 2012, so long term environmental effects are still unknown. It is obvious that the New Zealand government does not have the capacity to execute a massive project such as the Three Gorges Dam, but it does provide good warning as to the adverse environmental effects a large scale dam can have. New Zealand hydropower schemes seem to be performing better than this, particularly with civilian relocation.
21st Century Trends in New Zealand
Since 2000, eight new hydropower plants have been built in New Zealand. All small in scale, they reached a total capacity of 17MW <ref name= "Wright"/>. The majority of hydropower expansion during this period resulted primarily from improvements to existing hydropower stations, not a significant increase in the overall number <ref name= "Wright"/>. This decreasing number and scale of hydropower projects in the 21st century has been linked to increased environmental awareness, economic viability of dam construction and the difficulties in the consent granting process <ref name= "Te Ara"/>.
Increasing Environmental Concern
In the 21st century, an increasing attention to hydropower’s environmental impacts has been seen both globally and nationally in New Zealand <ref name= "Wright"/>. Increasing research and knowledge of the negative impacts of hydropower on the environment has hindered many attempts to implement new hydropower projects, and both the rate and scale of hydropower construction has slowed in the past decade. <ref name= "Wright"/>. Changes in global climate patterns have made it difficult to predict the stream flow and river morphologies of the future, and with a decreased ability to predict the future of New Zealand’s river systems, it has become more difficult to design effective dams <ref name= "Wright"/>. The physical construction of dams has gotten more difficult, as well. With fewer easily accessible locations for dam construction, the money, time, and environmental degradation associated with hydropower projects has increased <ref name= "Wright"/>.
Smaller Scale Projects
The economic viability of large-scale hydropower projects has decreased in the 21st century. Many companies and funding sources are not willing to invest in the enormous cost of larger hydropower schemes, and with increased resistance from environmental and conservation groups, smaller-scale projects have become more reasonable in recent years. A shift towards smaller projects has been seen across the country, including a 72MW water diversion scheme in Marlborough, a 260 MW project on the North bank of Lake Waitaki and a 14MW project diverting the waters of the Kaituna River in the Bay of Plenty <ref name= "Wright"/>.
Consent Granting Process
A significant obstacle for hydropower projects in the 21st century has been regulation and politics. In New Zealand, legislation is dictated by the Resource Management Act (RMA) which superseded the Water and Soil Conservation Act in 1991, the enactment of the RMA incorporated local water conservation notices into regional rules, giving weight for decisions to follow national government guidelines over local residence <ref name= "Wright"/>. The planning process involved with dam construction includes getting a resource consent through the RMA and permission under the Conservation Act of 1987. This joint consent process is an arduous procedure that can take years to be completed. Resource consents that must be obtained include; consents from the regional council to take and use the river water and to modify the bed of the river, and consents from the district council to clear vegetation, build roads, and construct the power station, more consents may also be needed if there is explicit protection upon the river <ref name= "Wright"/>.
Local councils can and still protect “wild and scenic rivers” through regional and district plans to give even stronger protection in a water conservation order. It is extremely costly to go through the joint RMA and Conservation Act permission granting process or even be involved in submitting against a proposed project - Fish and Game, for example, spent $543,000 on a water conservation submission on the Rangitata River for example <ref name= "Wright"/>. The funds needed to be involved with the RMA process when submitting against an application can be too high for public participation, as well. This can result in the primary means for public opposition being in the form of political pressure on the government or hearing commissioners. Even after the final decision of the hearings, decisions can still be appealed to the Environment Court as with the plan for a plant on the Mokihinui River by Meridian who later repealed the application all together <ref name= "Wright"/>. Other cancelled plans include a large scheme called Project Aqua proposed by Meridian that actually had significant local backing was dropped because the RMA process was costing the company too much which sparked a debate about the relationship between business in New Zealand and the RMA process <ref name= "Oliver"> Oliver, P., 2004. Speed up RMA, says business. The New Zealand Herald. Available at http://www.nzherald.co.nz/business/news/article.cfm?c_id=3&objectid=3558845 (last accessed 01/10/13) </ref>.
Future Trends in New Zealand
In 2007, the government of New Zealand set a goal on renewable energy production for the country. By 2025, 90% of the country's electricity is hoped to be from renewable sources, and this remains the current goal. In 2007, 66% of the country's electricity came from renewable resources, and in 2010, 74% came from renewable resources <ref name= "Wright"/>. With this goal in mind, there is still hope for hydropower, even with projects dwindling in scale and number.
With an increasing awareness and concern for global climate change, the governmental and non-governmental sectors of New Zealand must start complex conversations about the pros and cons associated with hydropower. While many aspects of hydropower dams are environmentally degrading, the atmospheric degradation from carbon energy sources, such as oil and gas, are very harmful as well.
While these conversations are already beginning, with fewer viable locations for successful projects, and increased resistance from many groups, wind and solar energy initiatives are expected to be the focus of the next decade in New Zealand. Their part in renewable energy production is expected to be the driving factor behind the next decade, and the main contributor toward reaching the government's 2025 renewable electricity target.
In order for a Hydroelectricity producing dam is constructed the degree of the environmental impacts of the proposed dam must be considered, both the long term and short term impacts. However, wherever the location of the dam, the impacts of the environment is the same but the magnitude of these impacts can be mitigated to a certain degree on the receiving environment so that the dam can be created in a sustainable way. The main Environmental Impacts are:
Creation of a Reservoir
The main outcome from the creation of a dam is the reservoir upstream. This reservoir will spill onto the receiving environment behind and flood the natural habitats that existed prior to its construction. This flooding leads to the destruction and decomposition of carbon-rich plants and trees which results in large amounts of carbon being released into the atmosphere from organic matter being broken down. This sediment/ plant matter also settles on the bed of the reservoir and if this is not mitigated then dissolved methane would also be released into the water <ref> Lin, Q. 2011. Influence of Dams on River Ecosystem and its Countermeasures. Journal of Water Resource and Protection, 2011, 3, 60-66 </ref>.
An increased in the water surface area behind a dam can also affect the local climate. By increasing the water surface area you also increase the amount of evaporation in the area which can alter the local climate depending on the magnitude of the reservoir / dam <ref> Tahmiscioglu, M.S. Anul, N, Ekmekci, F and Durmus, N. 2005. Positive and Negative Impacts of Dams on the Environment .International Congress on River Management, 2005, pg 759-769 </ref>.Another affect due to increase in water is the difference in water temperature due to a larger volume of water more energy is needed to warm the water so as a results this can alter the water characteristics and can potentially affect the biodiversity in that river <ref> Lin, Q. 2011. Influence of Dams on River Ecosystem and its Countermeasures. Journal of Water Resource and Protection, 2011, 3, 60-66</ref>.
Change in River Dynamics
The biggest effect in the creation of a dam is the reduction of the flow of the river downstream, the environmental indictor for this is the change in the Mean Annual Low Flow (MALF). By reducing the MALF the area of the river plan that is flooded of a frequent occurrence is reduced, this also reduces the total amount of nutrition and sediment that is deposited downstream, which can further degrade the quality of the ecosystems and soil fertility <ref> Tahmiscioglu, M.S. Anul, N, Ekmekci, F and Durmus, N. 2005. Positive and Negative Impacts of Dams on the Environment .International Congress on River Management, 2005, pg 759-769 </ref>.
As dams acts as sediment traps the rate of deposition downstream is also greatly reduced. As a consequence the river will erode away at the river shores and riverbed to replace the removed sediment, this will then deepen the riverbed and narrow the river over time. Which will then lead to a reduced water table downstream and a reduced stream level and will affecting the downstream ecosystems by reducing their life supporting potential as well as reducing the total amount of sediment reaching the coast and increasing coastal erosion <ref> Lin, Q. 2011. Influence of Dams on River Ecosystem and its Countermeasures. Journal of Water Resource and Protection, 2011, 3, 60-66</ref>.
Change in fish population/river species
A significant effect from the creation of dams is that they act as barrier for migratory fish. The dam will stop the migration for fish to upstream spawning areas with then threatens the population numbers in that catchment. However, some mitigation methods in the design of a dam have been created to help reduce the risk on fish population. These mitigation methods include using artificial fishways or fish ladders and the use of a barge to transport the fish, this may help reduce the affect the dam has on the migratory fish going upstream but fish have a greater difficulty migrating down-stream due the designs of the spillways resulting in a reduction in downstream populations <ref> Ledec, G and Quintero, J.D. 2003. Good Dams and Bad Dams: Environmental Criteria for Site Selection of Hydroelectric Projects. Sustainable Development Working Paper No. 16 </ref>.
As the change in river dynamics leads to a degradation of ecosystems, the change in habitats can result in certain fish species not surviving the environmental change and different species adjusting better and changing the characteristics of the rivers ecosystem. Dams also blocks the movement of debris downstream, debris provide a source of food and hiding places for all living organisms from phyto-plankton to microorganisms, so the reduction in the flow of debris will mean the bottom level of food becomes limited further more reducing fish population levels <ref> Tahmiscioglu, M.S. Anul, N, Ekmekci, F and Durmus, N. 2005. Positive and Negative Impacts of Dams on the Environment .International Congress on River Management, 2005, pg 759-769 </ref>.
Algal bloom problems
One of the results of damming a river is the reduction of the MALF, this also increases water temperature and reduces oxygen in the water. As a consequence the river below the dam has an increased threat of an Algal bloom and an increase in algae can produce compounds that lead to toxicity in the water which can destroy ecosystems and make the water unsafe for human consumption. The World Health Organisation indicates that 100,000 cells/mL is a moderate human health risk <ref> World Health Organisation (2013), available: http://www.who.int/water_sanitation_health/bathing/srwe1execsum/en/index6.html (accesses 30 September 2013) </ref>.
Socio-economic and Cultural Impacts
Hydroelectric dams vary in size from supplying a few kilowatts up to 800 megawatts at the Manapouri Power Station which was completed in the early 1970s, around when most of the main dams today came online. The energy returned on invested (EROI), the economic case for construction of hydro is heavily weighted on expected lifetime which is often around 100 years with turbine replacement after 50 years <ref name= "Drake"> Drake, E.M., Driscoll, M.J., Golay, M.W., Peters, W.A., Tester, J.W., 2005. Sustainable Energy: Choosing Among Options. The MIT Press, Cambridge. </ref> or <ref name= "Czerski"> Czerski, K., Gottleib,S., Huke, A., Hussein, A., Ruprecht, G., Weissbach, D., 2013. Energy intensities, EROIs (energy returned on invested), and energy payback times of electricity generating power plants. Energy. 52. pp 210 - 221 </ref>. With this long lifetime EROI can rival that of fossil fuels and nuclear with a value of 49 according to <ref name= "Czerski"/>, second only to nuclear with that of 75, see Figure 1. This is of course a generalization as these specific calculations used a top-down approach and can therefore not be seen as a purely economic nor a purely energetic factor. Specifics can be calculated through a bottom up approach as with Table 1 for the Waitaki Dam which returns an EROI of 50.
While this renewable technology may be a steady dispatchable resource in most countries, it is highly site dependent. Most key locations that are suitable for hydroelectric damming have already been utilized, especially in the industrialized world where the technology is most developed, the “low-hanging fruit” problem. It is this development that has benefited many local economies, supplying people with jobs for extended periods of time as dam construction can take 10 years or more and creating demand for building materials <ref name= "Sorensen"> Sorensen, B., 2011. Renewable Energy: Renewable Energy in Society (iv). Earthscan, London. </ref> . Although extremely reliable in terms of consistency, there are times of reduced output as with any technology that is powered by the weather. Drought, especially in more arid countries but also New Zealand in where in 1992 businesses were forced to use diesel, street lighting was rationed and households endured hot water restrictions <ref name= "McMahon"> McMahon, B., 2008. New Zealand faces power crisis amid drought. theguardian.com. Available at http://www.theguardian.com/environment/2008/jun/09/alternativeenergy.energy (last accessed 01/10/13) </ref>.
Social and cultural impacts
Population displacement is one of the hardest hitting social impacts of hydropower, being so location specific, certain sites are deemed more valuable for their energy resource than for settlement by governments and subsequently people are forced to emigrate. New Zealand citizens have not had to endure this as much as other countries with larger population densities such as India or China with limited land. New Zealand benefits from an abundance of high rainfall and upland valley locations away from major towns and cities which lead to its expansion of hydropower in the early 1970’s. Those displaced are normally from poorer backgrounds as it is extremely rare for a wealthy populous to be forced to move due to their influences <ref name= "Sorensen"/>. National policy can direct motivation for dam construction but it is usually local governments that have the control. Displacement is not always seen in a negative light by policy makers in developing countries as population flow from rural to urban countries upgrading low-yielding steep farmland and hopefully reducing forest logging and protecting mountain ecosystems <ref name= "Sorensen"/>. However resettlement is normally dealt with very poorly and problems arise with low compensation for the people or the environment, difficult conditions for resettlement and no proper mechanisms to guarantee the vital interests of local residents, leave local governments with a dilemma over national policy or benefits for local residence.
Opposition comes in the form of local residents to conservation groups like Fish and Game to recreation groups such as Whitewater NZ, a kayaking organization who opposed a proposal to explore feasibility for dam sites on the Matakitaki River in 2009 <ref name= "Whitewater"> Whitewater, 2009. Strong Opposition to Proposed Matakitaki River Hydro-scheme. Whtiewater NZ Media Release 29 July 2009. Available at http://rivers.org.nz/system/files/Whitewater_NZ_Matakitaki_Media_Release_2009-07-29.pdf (last accessed 01/10/13) </ref>. Recreation can bring positive change as well as negative, Lake Karapiro is a world-class rowing facility that has raised several Olympic rowers including gold-medalists Rob Waddell and the Evers-Swindell twins but inundated an important historical Maori site of conflict where in the 1820’s the Ngati Maru tribe were driven south by the Ngapuhi tribe who possessed muskets <ref name= "NZ History"> NZ History, 2011. Lake Karapiro – roadside stories. New Zealand History online. Available at http://www.nzhistory.net.nz/media/video/lake-karapiro-roadside-stories (last accessed 01/10/13) </ref>. New Zealand in especially unique in that Maori culture is still very much alive and certain projects are opposed because of the sites cultural importance, water resources in particular, as many of New Zealand’s rivers tie in closely with their cultural identity <ref name= "Wright"/>. Sites of cultural importance can range from specific sites to vast areas covering tens of kilometers. The Waitohi River area is associated with a historical Maori greenstone rail approximately 14 km long. The landscape has cultural value to tangata whenua as it remains similar to early Maori times with similar tussock and matagouri covered river flats and hill slopes <ref name= "Witter"> Witter, D., 2013. Archaeological Assessment of Effects: Waitohi Valley. HWP Waitohi Irrigation and Hydro Scheme Version 2. New Zealand Hisorical Places Trush Pouhere Taonga. Available at http://ecan.govt.nz/publications/Consent%20Notifications/hwp-waitohi-archaeology.pdf (last accessed 01/10/13) </ref>.
Legislation is already strong for the protection of residents from new hydro projects within New Zealand and as such requires less scrutiny than in the developing world. However, proper weighting should be applied to the value of important cultural and historical sites when following RMA 1991 and the Historical Places Act of 1993 with monitoring and analysis of effects upon said sites and where damage or destruction is unavoidable, mitigation in the form of archaeological excavation <ref name= "Witter"/>.
The legislation that covers archaeological sites in New Zealand is under the RMA (1991) and also the 1993 Historical Places Act. It defines historical places as either that which were “associated with human activity that occurred before 1900”, or “is or may be able through investigation by archaeological methods to provide evidence relating to the history of New Zealand” . This allows for the inclusion of many European settler sites such as the gold rush track in the Hurunui, Waipara and Kowai catchments or wagon tracks or old settlements.
Overall, a more in-depth, inter-disciplinary conversation about the pros and cons of hydropower in the context of climate change should continue to happen. The environmental indicators mentioned above should be used extensively to further research the effects and potential benefits of hydropower. While there are undoubtedly negative aspects to hydropower production, as climate change and loss of ozone continues to occur, these negatives must be re-evaluated in a larger context.
Revising the Consent Process
In order to increase the effectiveness and viability of hydropower projects, a revision of the consent granting process (through the joint legislature of the RMA and Conservation Act) should be considered. This would reduce the time and cost of getting a consent for hydropower, and may increase its use throughout the country <ref name= "Witter">. The RMA and Conservation Act joint consent process in planning new hydropower projects has made it expensive both financially and in terms of time and resources put into it. Since most prime locations for hydropower dams have already been utilised it is recommended that effort it put into other forms of renewable energy generation or in improving generation capacity at sites already constructed as with the Clyde dam for example, that is running off four 108 MW turbines with the capacity to install an additional two <ref name= "RMA"> Contact, 2013. Power stations. Available at http://www.contactenergy.co.nz/web/shared/powerstations (last accessed 01/10/13)</ref>. The proportion of renewable electricity grew from 66% to 74% from 2007 to 2010, primarily driven by new wind and geothermal, it is these technologies along with solar photovoltaics (as the price decreases) that will help the Government reach its target for 90% electricity from renewables by 2025. <ref name= "Witter">.