OPINION: The state of the Selwyn River is complex because of the huge impact of one of the most prolonged droughts in our recorded history. Historical and anecdotal records back to the late 1800s record the Selwyn/Waikirikiri as being prone to floods in winter and low or no flows in summer droughts. It is a foothills, south-westerly rain-fed catchment, so no southerly rain takes its toll.
The degree that irrigation versus drought has contributed to the current state of flow, especially in the lower Selwyn, is debatable. But it is a sad indictment on our ability as a society to manage our most precious resource if we think we have to choose between healthy rivers or paying the country’s bills.
Worse still, in my view, are those who believe that water – the essence of life – is best managed as some sort of commodity to be traded on the market for its ‘highest’ dollar value. All that means is the rich guys get to determine how water is used; and I’ve never seen a flounder or an eel with a credit card.
There is ample water flowing through Canterbury to more than meet the needs of all but we have to rethink how we manage it. We don’t have a water issue in Canterbury– we have a water management issue.
* No longer swimmable: A community mourns its lost river * Swimming hole on Canterbury’s Selwyn River reaches record low and nearly stagnant * Road or river? * Over the line: Rivers being whittled away
So let’s start with the most visible of culprits – irrigated farming. Farmers do not just take water; they have to apply for permission from the regional council. Water permits have conditions around the amount that can be taken and when. Surface water or stream-depleting groundwater takes have conditions requiring them to shut off at times of low flow. Last summer those taking water from the Selwyn River were shut off for more than 180 days.
There has been a long-running debate in Canterbury over the extent to which groundwater takes which do not have these measurable stream-depletion effects, affect flows in spring-fed streams. Some hydrologists take a view they do not and others that they do, depending on how they assume water is held in aquifers under the ground. I am aware of at least one case a few years ago where Environment Canterbury declined a groundwater permit on the basis of potential effects on lowland streams, but that decision was over-turned by the Environment Court.
So if everyone is playing by the rules – where to now for the poor old Selwyn/Waikirikiri?
As I see it, there are two options. We could spend millions of dollars in litigious processes trying to take away existing permissions to take water, but that may not make any difference to low flows. A few years ago Environment Canterbury spent over five years and a few million dollars reviewing conditions on groundwater consents in the lower Rakaia – Selwyn. Yet still we have low flow issues in the catchment.
Or we could try a different approach. We could look at how Mother Nature used to do it and see if we are smart enough to replicate her wisdom. In the days before European settlement, the Selwyn catchment had large areas of natural wetlands where rainfall water would be stored and released slowly into the river. The alpine rivers would also regularly overtop their banks and flood the land. The Waimakariri River used to flow into Te Waihora/Lake Ellesmere.
Trying to turn back the clock isn’t an option unless we want the citizens of townships such as Lincoln, Leeston and Halswell to grow flippers; and Christchurch might have a thing or two to say if we took away the stopbanks that protect that city from Waimakariri floods. But we can put water back into the Selwyn in a more controlled way.
Options include directly supplementing flow within the Selwyn or its tributaries, or irrigating the land using stored alpine water. That stored alpine water does not need to come at the cost of depleting those rivers. Mother Nature has a knack of putting plenty of water into alpine rivers at the same time as we need it.
Projects like Central Plains Water have the potential to do exactly this sort of thing. Through the work of many community groups supported by the Zone Committee process, Central Plains Water has become much more than an alternative source of irrigation water. We now have the potential to manage well both flow and water quality issues facing this catchment, with more initiatives to increase diversity in farming and reduce environmental footprints in the pipeline.
Our RMA system seems to encourage adversarial positions based on lots of finger pointing and litigation – but not solutions. We don’t need any more rules and court battles. We don’t need more blaming – farmers can point just as big and nasty fingers back to fishermen over didymo and lake snot and urban people over sewage and stormwater. It’s not helpful.
We have more than enough water to go around; we just need to find the will to work together, the wisdom to think unselfishly, and the courage to change the system when it stands in the way of solutions.