Putting Down the Glass: Water Use of Wine and Cannabis in California

There is no denying it, drought conditions have thoroughly hit California, particularly in the North, and are projected to get worse in the coming months.  In the context of this desperate need for water, both the wine and cannabis industries in the state have come into hot water, no pun intended, for their wasteful use of what little of this resource California has available.  However, with each industry thriving, there is some question as to whether they can both be environmentally sustained.  When considering the future of California, a little math needs to be done to understand the impact of each intoxicant on our rivers and reservoirs.

First, we must acknowledge that both industries are guilty of many of the same environmental infractions, such as clear cutting grow areas, over-exploitation of available water sources, and leaching of chemicals into the soil and local water supplies.  This is clearly unacceptable and steps need to be taken to curb it from happening.  Not surprisingly, just the opposite is the case.  There was recently a trial in San Francisco where grape growers sued unsuccessfully for the right to exploit the Russian River, despite evidence that it lowers the water source to dangerously low levels.  Although the two vineyards that brought the case lost, it shows an attitude of defiance, rather than cooperation, in the face of environmental destruction.

So how much water is actually at stake? Let’s examine the water usage at a typical California vineyard.  Hard numbers for wine grapes were hard to find due to major fluctuations in water use by type of grape.  However, average wine grape vines can appropriate up to 9-12 gallons of water a day in desert regions during the peak season, less where natural rainfall is higher.  Depending on the growing methods and location, the winery might also use massive quantities of water in winter for frost protection, which is often not included in “average water use” numbers listed by vineyards.  Even minor off season watering takes away from winter and spring filling of local reservoirs.

On the other hand, an outdoor cannabis grow will require an average of 6 gallons of water a day per plant over the duration of a 150 day season.  Once the growing season is over, though, the flowers are harvested and the plants are destroyed, meaning there is no water use needed in winter to keep the plant alive and avoid damage from frost.  Ultimately, it is clear that, despite claims to the contrary, marijuana grows simply use less water than vineyards per plant.

Marijuana also wins when it comes to the productivity of each plant.  Cannabis plants manufacture, on their lowest end, 250 grams when grown outdoors, where a skilled grower might harvest up to 700 grams or more per plant.  However, each grape vine only delivers 5 bottles of wine a year on average.  Depending on the bottler’s techniques, this number can range from 10 bottles down to just one.

You may be thinking that those numbers are meaningless and that comparing wine and cannabis quantities impossible due to differences in toxication and tolerance.  Once again, looking at average numbers puts this difficult contrast into perspective. Regular wine drinkers make up 90% of consumption, swallowing 60 bottles a year per person, while the average drinker sips down around 15 bottles.  Marijuana users clock in at just 61.5 grams a year, with 20% of users consuming 80% of the cannabis produced.  This means that, while it takes upwards of 12 vines to keep one wino in hootch for a year, one single cannabis plant can satisfy eight stoners for over 365 hazy days.

As our state continues to ponder the question of legalizing recreational cannabis in the coming years, the health of our environment has become a key piece of the equation.  The numbers show that the wine industry uses significantly more water in their processes, sucking up far more of this natural resource than cannabis growers.  For our own sake in this time of drought, our direction seems clear.  California needs to put down the glass and pick up the bowl.