Not too long ago, I went to a presentation talking about the water footprint of the food system. There were a lot of surprises– how much water do you think it takes to grow and produce enough coffee for an 8 fl. oz cup*? Unsurprisingly, the footprint of individual foods varies dramatically depending on how and where it is produced. The obvious factors are, of course, how it is processed, whether it’s irrigated, what type of irrigation system is used, and simply whether it is a crop that needs lots of water. If you look deeper, you’ll find that the energy used to produce inputs like fertilizers, pump the water out of the ground, fuel farm machinery, process, store, and transport the items depends on water use (or misuse). Reducing water consumption in the food system means that we must not only work on water conservation in the field but also on reducing overall energy consumption.
What are some system changes that can conserve water?
1) Improved irrigation practices (drip, for example, instead of flood)
2) Shifting crops to more appropriate climates (why exactly do we grow a lot of lettuce in the middle of an Arizona desert?)
3) Encouraging groundwater recharge and reducing depletion of aquifers through less irrigation and good soil management practices like avoiding compaction, gully formation, and high run-off rates
4) Reduce water transfers out of watersheds by minimizing shipment of water-heavy items to distant watersheds without reciprocal trade
What can you, the individual, change to conserve water?
1) Switch from coffee to tea a few times a week, or go caffeine-free
2) Choose foods with lower water footprints, like lettuce grown in temperate areas during the growing season instead of lettuce from arid areas in the off-season
3) Eat seasonally (US)
4) Utilize household water conservation techniques in the kitchen, like this post suggests
Generally educating yourself can help, too. Try this calculator to see what your footprint is, and how much food contributes to your overall footprint. What surprises you? What can you change? What can’t you imagine changing?
*140 liters, or about 32 gallons.