The amount of water used for agriculture in California – Full disclosure


I gave a talk to the Urban Framer Meetup at the Craftsman restaurant in San Jose and at one point during the presentation I presented a slide which stated the percentage of water in the state dedicated to agriculture. Many news media have reported this number to be 80% with the remaining 20% being used to provide water to cities, towns and industrial processes.

Where to Start Conserving water in California

My point to the statistic was if any low hanging target of where our water footprint might be reduced agriculture would be a decent place to start.  I had anticipated being asked for more details about the breakdown of the 80% but the question failed to be asked.  The only problem after reviewing more data after I gave the presentation I determined the number I presented fell short of being as correct as possible. The 80% number is in reference to “non-human” uses of water. For example, water is required to prevent salt water intrusion into the Sacramento- San Joaquin River Delta. The truer percentage of “human” water use for agriculture is closer to 40% with 50% going to environmental uses like rivers and streams, and the final 10 % making its way to urban environments such as cities and towns. Now let’s be clear, this still is a lot of water dedicated to agriculture.

Where the California’s water actually flows

The environmental uses include wild and scenic rivers which protected under federal law use a whopping 31% of the state’s water. California keeps water flowing in some of the state’s rivers at a certain rate for recreation, environmental reasons or both which takes an additional 9%. The state’s managed wetlands receive 2%.

Ahead of my next presentation

In preparation for the next time I give this presentation I will update the slide.  The justification for conserving our water in this case and sustainability in general is valid enough without inflating the numbers to achieve added impact. The implication and consequences of not conserving water should be more than enough.

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