A trend of declining rainfall is expected to continue
The Gisborne District escaped an El Nino drought over summer but a glance at the newly released state of the environment report to Gisborne District Council shows that the future holds problems.
The report says the 126-year rainfall record for the Poverty Bay Flats shows a gradual declining trend in both summer and winter rainfall. This gradual decline can also be seen at the district’s other long-term rainfall sites at East Cape, Ruatoria, Te Puia, Tolaga Bay, Puha, Waipaoa Station, Mokairau and Otoko.
Climate change projections from Niwa identify a further decrease out to 2090, with a consequent decrease in mean seasonal river flows, particularly in the spring.
In the Waipaoa River at Kanakanaia, decreases in the mean annual flow of 14 percent by the 2040s and 24 percent by the 2080s are predicted.
In many ways there is nothing new about these figures — the trend has been evident for some time. It does however flag to the key horticultural sector that some innovative thinking is required.
It also increases the need for the council to complete its freshwater plan, because water is going to become an increasingly important issue and one with strong political overtones. The Poverty Bay Flats are over allocated now but not all the water rights are taken up.
The recent decision of the council’s environmental planning and regulations committee to begin charging administration fees to the 156 water consent holders is interesting in this respect. At this stage it is a recommendation to the full council.
Then there is the proposed Makauri aquifer recharge project, for which the council must seek a resource consent.
After enjoying a summer that seemed endless and revelling in midwinter weather that would be considered summer in many other parts of the country, we must realise that there is another side to our good fortune.
Global warming is predicted to result in more severe weather events, both droughts and storms. The problem is that when that rain does come, it will sometimes come all at once.