After all, “where there’s good water, there’s good wine.”
World Water Day is celebrated every year on 22 March. For many of us, water is a natural resource that we can access quickly and instantly with a simple turn of the tap. However, according to the United Nations, “billions of people around the world are still living without safely managed drinking water and sanitation even though access to both services has long been recognized as a human right”.
A direct line can be drawn from the lack of an adequate clean water supply to poverty and a serious negative impact on human and environmental health.
During the UN Water Conference held in New York in March 2023, participants identified two key problem areas:
– Approximately 35% of treated water is currently lost in urban water systems.
– At least 1.4 billion people have been affected by droughts and 1.6 billion by floods between 2010 and 2019.
Once more, these data points demonstrate how essential the sustainable use of water is in addressing the climate and environmental emergency and building resilience.
Water and wine
In the wine and grape sector, water naturally comprises 85% of the total content of wine. Calculations show that it takes 109 litres of water to produce a 125 ml glass of wine (Water Footprint Network). Far more than the 74 litres that it costs to produce 250 ml of beer.
These results reflect what is known as the water footprint. This indicator calculates the amount of water consumed across the entire life cycle of a product, from the production of materials needed for its manufacture to its ultimate disposal.
When we say that a glass of wine contains 109 litres of water, we are referring to all of the water used to produce said glass of wine: grape growing and processing, bottling, etc.
Water is a natural ingredient of all wine, but at what stages of production is it actually consumed?
Let’s start at the beginning: in the vineyard. Water consumption in the vineyard mainly corresponds to the actual water needs of the grapevines.
The real value of the vineyard’s water needs is usually related to parameters such as evapotranspiration* and other site-specific data such as location, type of variety, nutrient and mineral levels, and plant density.
Although vines are capable of surviving on very low levels of water consumption – it is believed they can make it through their entire annual growth season on approximately 300 mm of water – they do need a certain amount of water depending on the stage of their growth cycle (budbreak, budding, bloom, veraison, autumnal growth, leaf fall, winter dormancy). The period in which the vines require the most water is between budbreak and veraison.
Various strategies are available to winegrowers to reduce the water footprint of a vineyard, including genetic improvements through the selection of more drought-tolerant varieties, the technical modernization of irrigation systems, harvesting rainwater, and irrigating more efficiently.
At the Paso Robles vineyards of Tablas Greek, the team carried out a successful transition from irrigation to dry farming over the past two decades and implemented several changes to improve the water holding capacity of the soil. These include organic, biodynamic, and regenerative farming approaches, a flock of sheep and rotated grazing, biochar applications, cover crops, and the use of Keyline ploughing to encourage soil water absorption. Taken together, these strategies hold great potential in terms of reducing water use in warm and dry climate vineyards.
Moving on to the winery, we find that certain areas represent the lion’s share of water consumption, even though each winery is, of course, different. According to the Sustainable Water Management Handbook for Small Wineries published by the California Winegrowing Alliance, these areas include the following:
· Barrel and tank washing and sanitation
· Bottling line sterilization
· Vacuum pumps
· Wine pushing
In addition, 30 to 50% of the annual water use of a winery generally occurs during the 60-day harvest period.
In order to introduce an effective water management system in our wineries, it is therefore necessary to establish an internal methodology that allows us to set goals, and compile and evaluate existing data about water uses and water sources, and to conduct an in-depth evaluation that will lay the groundwork for an action plan.
The Jackson Family Wines wineries have reduced their overall water use by 43% since 2008 through internal activities such as redesigning their barrel washing process to reuse the same water several times, real-time water readings, UV waterless tank cleaning, and air-cooled chillers.
For many wineries, the monitoring and filtering of effluent is still a pending task. Systems to separate solids from the water are needed, because winery wastewater may contain solid particles that constitute a source of pollution.
The project WETWINE is built around a system to treat and recover wine production waste. It is a project within the Interreg Sudoe transnational cooperation programme, co-financed by the European Regional Development Fund, with eight participating partners from Spain, Portugal, and France.
Using low-cost natural technologies, the project shows the viability of constructed wetlands as a management model for vinicultural effluent, allowing for both the treatment of wastewater for its subsequent reuse in irrigation and the recycling of biosolids as fertilizer.
The fact is that water is inextricably linked to wine, both in terms of its production process and its natural content. As members of the wine and grape sector, we have a responsibility to develop and work on initiatives to reduce consumption, use water effectively, and treat wastewater correctly to prevent further environmental pollution. After all, “where there’s good water, there’s good wine.”
Marta Juega, PhD.
*Evapotranspiration (ET) is a combination of two processes: evaporation from the soil and the surface covered by plants, and transpiration from the leaves of the plants themselves.
