By Daniel Collins
Since 1993, March 22 has been World Water Day. Its purpose is to raise awareness of the importance of water to society and of the challenges people face in securing sufficient and safe water. Like many efforts run by the United Nations, it fosters collaboration between the economic and hydrologic haves and have-nots, and cooperation among riparian nations*.
The water-energy nexus
The theme for this year’s World Water Day is water and energy. Water is required to generate almost all forms of energy, and energy is needed to distribute and treat water. In New Zealand, a little over half of our electricity is generated renewably at hydropower stations, and even thermal power stations need water for cooling. Summer irrigation has also changed NZ’s profile of energy use, and even electricity prices affect how much water is abstracted.
Our largest capacity hydroelectric power station is the 850 MW Manapouri scheme, conveying water from Lake Manapouri through an underground station to Doubtful Sound. Built in 1971 largely to serve the Tiwai Point smelter, it also helped to galvanise a generation of environmentalists concerned with effects of raising the lake level.
As with most uses of water, hydropower generation has its benefits and its costs, depending on your point of view: a renewable, low-carbon energy source; cheaper energy, depending on the geography and availability of other resources; loss of cultural spaces; loss of ecological habitat and natural character; different recreational opportunities; and altered risk of flooding.
WWD events in New Zealand
Perhaps because water is increasingly in the news, New Zealanders don’t need as much reminding of its importance. Or perhaps because we are so concerned with water that we need to learn or do more. In Christchurch there will be two public events this Saturday to help quench you World Water Day:
- The NZ Hydrological Society, Nature Watch NZ, and the Styx Living Laboratory Trust are running a citizen science workshop at the Travis Wetland, from 10 am – 1 pm. Listen to experts talk about stream monitoring, why it’s important, learn how you can do it in your own group, and even give it a go there. Travis Wetland Education Centre, off Frosts Road, Christchurch.
- Castle’s and Sons Brewery is hosting a Heathcote River clean-up from 10 am. Refreshments provided afterwards. 3 Garlands Road, Woolston, Christchurch.
If you know of other events, please share them in the comments below.
* Riparian nations share the same river basin, e.g., the 10 nations with land draining into the Nile.
Dr Daniel Collins is a hydrologist and water resources scientist at NIWA.