A leading figure in wine sustainability says winegrowers and wineries need to use water more efficiently as climate change shrinks rivers and aquifers, which is already happening to Marlborough’s Wairau River.
Marta Mendonca, head of viticulture sustainability organisation The Porto Protocol Foundation, spoke on the issue to winegrowers from around the world at Blenheim’s ASB Theatre on Tuesday, for the Organic and Biodynamic Winegrowing Conference.
Mendonca said the wine industry needed to treat water less like a tool and more like a source of life. A more holistic view would help the industry navigate the effects of climate change, she said.
“We know water is life … it nourishes our vines, it shapes our yield and quality and it shapes our mind as a whole.
“It’s sacred, it’s alive.”
Mendonca urged winegrowers and wineries to look at their water footprint, the volumetric measure of water consumption and pollution impact per unit of product.
The framework took into account naturally occurring rainwater in the soil, irrigation and ground water, and the water needed to dilute pollution.
“It takes into account the source, it takes into account time and location, and it also takes into account indirect water use.”
Indirect water use in the production and bottling of wine was an area where significant water savings could be made, she said.
“Simply reducing the diameter of the hose [can] actually achieve really impressive results in terms of water reduction.
“Cleaning tanks with UV lighting has water reductions in terms of consumption of about 90%.”
Mendonca said that wine companies were so focused on reducing their carbon footprint that they had not considered their water footprint.
“We don’t even know if we have the answers, but we’re not even asking the question.”
Mendonca said that water metering was an important start for measuring water footprint, but winegrowers need to go beyond simple metrics.
“This is our invitation, to go beyond measurements and to call for deeper situation.
“Measuring litres is a start, understanding systems is the goal.”
Charlotte Tomlinson, environmental scientist for Marlborough District Council, told attendees that a combination of climate change and flood prevention works had contributed to a decline in the Wairau River’s aquifer levels.
“The aquifer level has dropped since the 1970s by about 1m,” Tomlinson said.
“This will, and is starting to, have effects on spring and river flows in the lower Wairau.
“Our job is to start looking at ways to decrease or stop this declining trend in the aquifer, because this will have impacts on how much water may be available for use in the future.”
Tomlinson said that Marlborough would face water shortages earlier each year as spring and summer became hotter and dryer.
“You really rely on that spring rainfall and river flows, generally to top the [Wairau] aquifer up.
“So if we start to see spring and summer getting a little bit drier … we’ll likely have less water available to allocate to outward stream users when they need it most.
“Which means that efficient use of water will be key.”
By Kira Carrington for Local Democracy Reporting
LDR is local body journalism co-funded by RNZ and NZ On Air.