If little or nothing is done to address the impacts of climate change on water supply and reliability, the current way of life in the valley for all of us will change quite significantly.
Climate change is being felt now by the people, rivers and environment of Wairarapa and will dominate in the future.
In August last year, the Greater Wellington Regional Council (GWRC) declared a climate emergency and stated that Climate Change is one of the region’s biggest challenges.
This was on the back of a NIWA commissioned report in 2017 that described significant impact for the Wairarapa:
- The Wairarapa will experience a significant increase in hot days, (the number of ‘hot days’ - classified as above 25°C - will nearly quadruple from 24 to 94 by 2090)
- Annual rainfall on Wairarapa’s valley floor is expected to fall, 10-15% by 2090
- The risk of drought will increase in the Wairarapa
- On average, 15% more water will be required by mid century and 30% more by late century to maintain soil moisture levels assuming current land uses
- Frosts in the high elevations of the Tararua Ranges is likely to disappear
- In the next 20-years, on average, Wairarapa is anticipated to have a climate more like Hawke’s Bay and Poverty Bay, reflected in what is called growing degree days.
- By 2090, Wairarapa’s growing degree days will be similar to that of present day Northland.
IMPACTS & OPPORTUNITIES
- An increase in drought would have significant ramifications for food and fibre production and flow on effects for water supply.
- But while more droughts may limit pasture production and crop growth, warmer temperatures may allow for different crops to be grown with the possibility of multiple rotations. Countering against this is the likely stress on water reliability, expected to come under increasing pressure.
- Reduced water availability and reliability will place many Wairarapa businesses in economic jeopardy and create uncertainty around potable town supply.
- Reduced river flows in dry periods also presents major risks to the health of waterways and waterbodies, including Henley Lake and Queen Elizabeth Park’s Lake of Remembrance.
- Enhanced availability of water, (made possible with storage), at times of low flow, will help us meet new environmental requirements introduced by the government.