Placing a dam on a wild 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.
Hydro developments and irrigation dams 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
There is hardly a river on the east coast that hasn't come under pressure from irrirgation demand. Many of the proposals involve dams. In the past decade, the government has been subsidising and financing the development of water storage for irrigation.