Questions
2. What are the threats to our wild rivers?
3.Aren't they protected already
5. In what way are our species affected by the damming of wild rivers?
6. How does it upset the flow of the river?
8. Does dewatering do more damage than damming?
9. How are others affected by damming?
10. Compared to alternative renewable energy sources how does damming stack up?
1. What is a Wild River?
Our wild rivers are in the more remote and inaccessible places in New Zealand, mostly within public conservation land. They are surrounded by intact forests or tussocklands, with high water quality. Frequently they drain our high mountains, and thread their way through mountain ranges or plunge over waterfalls on their way to the sea. They provide a rich habitat for a variety of indigenous life, including fish, water birds, and dwellers within the riparian margins.
A wild river flows freely without major abstractions or alterations to its natural state. Some of the rivers are wild from the source to sea, but many of them flow wild in the mountains, and then become modified as they reach areas of human habitation.
2. What are the threats to our wild rivers?
As unsustainable industries and consumption starts to drive unreasonable expectations for water, many developers are looking at the wild rivers on conservation land to provide cheap and nasty hydro electricity, or free water for irrigation. Some, like the Mohaka in the North Island, are polluted by runoff from unhealthy farm practices. In some regions, up to 90% of the proposals for hydro electricity generation are on public conservation land. This is land that has been set aside to protect important biodiversity values and recreation opportunities. Because dams have well documented negative effects on waterways, their construction in the conservation estate will destroy important habitats.
3. Aren’t they protected already?
Not all rivers within public conservation land are protected – many of them aren’t. Only 16 rivers in the country (less than 10%) are protected through the mechanisms of a Water Conservation Order – and this can be altered after only TWO YEARS! Wild rivers need as much protection as our national parks.
4. How are we going to cope with increasing electricity demand (with increased net migration etc), if we don’t look at hydro-electric options?
Current growth rates of up to 2% are unsustainable in the long term. It would mean damming a wild river every 6 months. We have to look at other options. One of the cheapest and easiest options is to improve efficiency and conserve more energy. The Electricity Commission states we could save 6400 gigawatt hours per year more cheaply than installing new generation. Our rivers are not renewable, and any hydro-electricity generated from them already needs to be used wisely. Some micro-hydro schemes may still be able to be installed and retain the integrity and functioning of our rivers. These are best sited near where the electricity is required, not in remote and wild places. Other options for new generation include alternatives like wind and solar, and investment in new technologies like wood waste, and tidal.
5. If there’s a threatened species on a river that is being dammed, can’t we just re-locate it, so it can establish a population elsewhere?
Species live where they are for a reason – it provides them with the homes, food, and social networks they need to survive. Some species can only survive in particular habitats. Moving them to somewhere else displaces the species that are already living there. With biodiversity on the decline nationally, we should be looking at more places to protect, rather than destroy more.
6. In what way are our species affected by the damming of rivers?
Their homes become flooded, their food supplies disappear, and their important connections between the mountains and the sea (e.g. for spawning) are disrupted. In most cases fish do not adapt well from living in a fast flowing river, to a deep and oxygen-deprived lake. Riparian vegetation – often important for smaller native birds – disappears, and cannot be replaced within the altered environment.
7. How does it upset the flow of a river?
Placing a dam on an unmodified river is like severing a spinal cord. Rivers are important transport corridors for sediment to travel from our mountains to replenish the coast, for fish to migrate to the sea, and for natural flows to provide habitat for fish, invertebrates and riverside plants. A dam halts the flow of the river and holds up the sediment (in high earthquake areas a dam could fill up within decades). River flows are also ‘manipulated’ to provide power at peak periods of the day. Although a river fluctuates naturally when it rains, a river NEVER flows on and off twice a day like a tap. Some rivers if dammed, like the Mokihinui, would be running at up to 120 cumecs from 9am – noon; and then again from 5 – 8 pm. The rest of the time, including all through the night, the flow could be as low as 16 cumecs. In such an unnatural environment the river becomes uninhabitable for several species, and destroys the feeding zones at the margins of the river.
8. Does dewatering do more environmental damage, than damming?
Damage can only be properly assessed on a river by river basis. Because abstraction of water doesn’t flood an area, habitats can be saved. However dewatering a river is removing the very life force that is needed to keep the ecosystem functioning, i.e. water! It is all about determining how much water, if any, can be taken from a river. In wild and remote places, where wilderness is valued, any abstraction may be harmful to the local environment, especially if it brings with it associated infrastructure like roads, building, construction dams/weirs/pipes. Along with humans and disturbance often follows pests and weeds. These wild and remote places act as refuges for many of our species. We need to keep them wild to keep it that way.
9. How are others affected by damming?
The most important ‘party’ that pays the price are the species that inhabit the area affected. These are not just ‘environmental damage collateral’, they pay the price through localised extinction, increased threat status, and loss of capacity to support their ‘way of life’. They do not have the same capacity as humans to make adaptations.
Human parties that are affected are:
• Local communities that are displaced and disrupted, affected by roading, noise, dust, and permanent changes to their local environment
• Recreational users – loss of ability to utilise their place they love to play. This includes, kayakers, rafters, trampers, botanists, anglers, ornithologists, families, wilderness seekers, jet boaters, etc.
• Those that value the intrinsic nature of our river ecosystems
• Wider community as we fail to address means of arresting the unsustainable growth in electricity.
o Opportunities are lost to consider reductions in power consumption and efficiency measures
o Homes and businesses ‘waste’ power and this costs them financially
o Future generations lose the chance to see our rivers ‘the way they were’, and the stories of their magnificence are relegated to fairy tales.
10. Compared to alternative renewable energy sources how does damming stack up?
Dams are the most ecologically damaging to river systems of all the hydro-electricity options. Hydro-electricity is one of the most damaging of renewable electricity options. The irreversibility of effects on a river system (i.e. the river’s capacity is not sustained) can be juxtaposed against appropriately sited and constructed other options, i.e. wind farms, potential tidal opportunities. The wind flows through the turbines, and is largely unaltered by this experience, it has not been impounded. It does mean that issues like bird flight paths and micro climates need to be considered. With tidal opportunities, once again the water is not impounded, and provided it does not affect the paths of marine species (i.e. they can pass safely), and respects local habitat, then it may be suitable. Of course everything has to be taken in context.
The obvious answers are:
• Better integration of the electricity market so that it addresses matters of conservation and efficiency as priorities – and reduces competition and the need for ‘growth’ as end targets
• Better accounting models for the effects of our energy production to include the cost to the natural environment
• A model of sustainability that recognises the limits to growth incorporated into decision making on the environment, e.g. through the RMA and other relevant legislation
• Recognition of the importance of our indigenous biodiversity and natural features in terms of continued threats, increased losses, ongoing species extinctions and decline.
For more information on Energy Solutions, see here
11. Another of the reasons why rivers are being dammed is to store water for irrigation. What’s wrong with that?
Storage of water for future use is a sound premise. It is good practice and helps supports our capacity to provide food for ourselves and our animals. The problem with water storage for irrigation is about how it is done and what the end use is. Destroying ecosystems to provide for water storage is ecological damage. Many people look at flood waters flowing out to sea and cry ‘waste’! These flood flows are essential dynamic processes that replenish our coasts, cleanse our rivers of weeds and provide fresh habitats for river birds and fish. The effects of dams are well documented, therefore any water storage systems should take into account the surrounding environment and what is needed to sustain it. Some water can be stored in other systems, e.g. the restoration and protection of wetlands. Some water storage areas can be created on farm and provide for renewed habitat. However, in New Zealand, water is often stored to be used in farming practices that have become increasingly unsustainable. The demand for water in some areas, like Canterbury, is higher than the river can provide after ensuring the protection of the ecosystems on which it depends. Because of the high value placed on farmland, the farming sector is very reluctant to look at storing water on farm properties, and instead look to the foothills and gorges of the high country – often within public conservation land. They fail to see the value and importance of these places as habitats for our biodiversity. Dams used for irrigation also have very large fluctuations in the reservoir level. During the winter months the demand for water is negligible, but in summer, after a dry period of a few months, the reservoir will be almost empty – creating a dust bowl in an increasingly arid countryside.
Irrigation is also being used to transform our landscapes, our aquifers and our lowlands into a monoculture of dairy farms. This is inherently unsustainable as a farming practice, contributing to increased water pollution, the removal of trees, and – like in the Mackenzie Country – the destruction of our tussocklands. The intensity with which dairy farming uses water is of a much greater magnitude than other farming types. With the advent of ‘housed’ cows through the winter months to retain milk production, water will become even more of a commodity. It will be in greater demand for drinking (stock will be eating dry food as opposed to fresh), cleaning of sheds, and of course, the significant amount of water that is used to produce a single litre of milk. The effluent from these housed animals will be deposited on our lands, and absorbed further into our waterways.
