The Climate Chap: Wet, wet, wet

04 Oct, 2021

My favourite Scottish pop group, but this article is all about freshwater and how the climate crisis is impacting Mangawhai.

For centuries mankind has taken freely available water for granted. Communities have never developed without convenient and consistent access to free water. Whether for drinking, cleaning, farming, or river transport… no water, no community.

Sadly, globally almost 1.9 billion people now live in “severely water-scarce” areas. This is expected to rise to 3.2 billion people by 2050!

In New Zealand we are fortunate that there are more than 425,000km of rivers and streams and about 4000 lakes and over 200 underground aquifers. Annual water flow is 145 million litres per person. This water comes from the sky. This historic reliable supply of good water has been an important economic advantage for New Zealand, but its quality and availability are declining.

The decline in quality is mainly due to urbanisation combined with increased dairy farming. Sadly, both continue to contribute to pollution. The 145 million litres per person is slightly deceptive. Chances are that this is more than you personally use. Regrettably buckets of rain fall over the west coast of the South Island and is of minimal benefit. Over recent years we have experienced hotter summers and less rainfall throughout the North Island and the east of the South Island. This has already resulted in significant restrictions being applied to major cities.

It is estimated that over 70 per cent of global freshwater is consumed by irrigation. Only 30 per cent is available for industry and home use, and sadly the demand from our major cities frequently exceeds supply at a time when our government is reluctant to invest in new reservoirs or repairs to our ageing urban underground infrastructure. This is now so bad that tons of water leaving reservoirs never arrives at anyone’s tap! Add to this the anticipated urban population growth of a million over the next 30 years and we simply will not have enough water where and when needed.

The reduced rainfall has also had a very negative impact on generation of hydro-electricity at a time when we need far more to support our electric homes, cars and growing population. We are importing coal to cover this shortfall.

The great news for Mangawhai residents is that we are currently well positioned by relying on water tanks, sitting on two aquifers that support lots of bores (that’s drilled water, not you personally), and access to quality and affordable tanked-in water. As a community we are effectively self-sufficient. However, with reduced rainfall potentially increasing demands on the aquifers (think Tara Iti golf resort and Mangawhai Central) possible contamination of the aquifers due to rising sea levels, and more competition for tanked-in water, it is now timely to consider conserving water on a daily basis and investing in an additional water tank if you frequently run low.

As mentioned, our climate is changing quickly, with rainfall reducing in frequency while temperatures are steadily rising. Mangawhai is destined for hotter and drier summers. This is resulting in a lessening of the supply of useable water, more violent storms, and more and more rural land becoming drier. The impact on our national horticulture, pastoral and arable farmlands is likely to be incredibly impacted by these changes.

In locations such as South West USA the development of new towns is being abandoned due to this water crisis. The Colorado River, the source of water and electricity for most of California

and Arizona, is drying up and the aquifers supporting California’s amazing horticulture industry are running dry. Saudi Arabia has stopped growing feed for cattle as there is now insufficient water. They are buying arable land around the world to grow alfalfa and export it back to their desert.

New Zealand should be okay, but to secure our future we must look to water being a strategic, national and priceless asset, and to maximise its storage, quality and availability. Our government must stop overseas companies bottling and exporting water for free and to take back ownership from the nearly 70 local authorities each of whom act parochially and independently. No longer should an authority be allowed to restrict a neighbouring authority from accessing what is a national asset!

It is now timely to consider conserving water on a daily basis and investing in an additional water tank if you frequently run low.

For centuries mankind has taken freely available water for granted.