Banks Peninsula, water and climate change.
Several years ago the Trust identified climate change as a looming issue both globally and for the Peninsula.
Since then the effects have become increasingly apparent. We have fewer Southerlies and more weather from the North and Nor’west. We have high tides which get higher and higher and the average temperature increases month on month, year on year*.
Banks Peninsula is an ancient landform. It is at least 12 million years old and was an island volcano long before the Alps were formed. The Canterbury Plains owe their existence to this island, which acted as an anchor to hold alluvial shingle in place.
These geologies are as different as chalk and cheese. This means that the only fresh water available to us is what falls on our heads. There is no subterranean connection to another supply.
The relative infrequency of Southerly weather has resulted in less rain fall overall, even if downpours occur from time to time. This is a trend which will become more and more apparent and we must begin to adapt, sooner rather than later.*
Valuing water is the first thing. I don’t mean monetary value but its intrinsic value as a vital resource. Our drinking water supplies have always been precarious and can only become more so when you consider the demands put upon the supply. We need stock water for our farmers, we need water for everything.
We should be nurturing all our streams by fencing and planting every significant waterway.* We should manage our water consumption and use water storage as much as possible.
The Tonkin & Taylor report on sea level rise, commissioned by the Christchurch City Council in 2013, uses projections made in 2009. Since then the rate of sea level rise has doubled to 4mm per annum.
The report highlights the impact on low lying coastal environments and, despite being a very conservative document, makes very sober reading.
Inundation will not only effect the lower lying coastal settlements of Banks Peninsula but it will impact on access. We should start to lobby Transit New Zealand about the status of Highway 75 and the Christchurch City Council to assess the magnitude of these issues and get them in the Council’s Long Term Plan.
The National Institute of Water and Atmospheric Research publication “Coastal Adaptation to Climate Change - Pathways to Change” 2010-2025 identifies the four steps needed to get some action.
Awareness and Acceptance: Assessment: Planning the Way Forward: Implementation.
We’ve taken a long time to make the first step, so now is the time to take the next, and the next, with a degree of urgency. The changes to our climate, which are now a matter of record as much as projection, will not happen in a comfortable, linear way. Change will be erratic, accelerated and implacable.
Have a look at the monthly website; <stateofourclimate.com>
It’s time to adapt.
*Metservice Historical Data.
*Christchurch City Council: Water Supply Strategy 2009-2030.
* The Banks Peninsula Zone Committee of the Canterbury Water Management Strategy has funds of $500.000 over the next five years to subsidise fencing and planting.