Our rivers are not ‘renewable’
“Renewable’ energy is touted as environmentally preferable to energy created by burning fossil fuels, but hydro development involves the destruction of our rivers natural and scenic values, ecosystems and recreation.
Hydro developments reduce the river flow, causing several problems downstream (see diagram - click to enlarge) such as –
- Increasing the temperature of the river, increasing algal blooms & pest plants
- Reducing the amount of ‘island’ nesting sites for birds
- Blocking the fish passage to and from the river
- Drying out wetlands
The government has boldly committed NZ to producing 90% of its electricity from renewable sources by 2025, up from 74%. It is important to decrease New Zealand’s dependence on non-renewable sources such as coal, oil and gas, and therefore important to increase the proportion of electricity generated from renewable sources like geothermal, wind, biomass and eventually tidal and wave.
The destructive potential of building hydro-dams on wild rivers to meet this demand is immense. To meet just 40% of this need through hydro-electricity, we would need to dam or divert the Waitaki, Clutha, Ngaruroro, Wairau, Whanganui, Hurunui, Mohaka, Mokihinui, Grey, both Waiau rivers, the Taieri, Rangitikei, Rangitaiki, Waiaou, Raukokore, Waikato, Patea, Waimea, Ruamahanga, Awatere, Wairoa, Manawatu, Tukituki, Whakatane, Pelorus, Ashburton and Tarawera rivers.
On the Mokihinui alone, more than 20 endangered species live in the healthy forest and river of the Mokihinui Gorge. Some of them, like the whio (blue duck) have suffered from serious habitat depletion, much of it a legacy of concerted hydro building throughout the mid 1900s.
Finding alternative energy sources, such as wind-farms amd geothermal power-stations will cut down the pressure on our wild rivers. On top of this, individuals need to look at how they can reduce their energy needs to help save our wild rivers, and the species that call them home.
