Whereas agriculture used to consume 80 percent of the state’s water supply, today 46 percent of captured and stored water goes to environmental purposes, such as rebuilding wetlands. Meanwhile 43 percent goes to farming and 11 percent to municipal uses.
— The Economist, October 2009
By Jeffrey Mount
This excerpt is from an article that focused on the never-ending skirmishes over how to divide the water of California and simultaneously meet the objectives of water supply and ecosystem health in the Delta. The statement, which appears to be attributed to Tom Birmingham of Westlands Water District, is both a mangling of the facts and an apples-to-oranges comparison.
Interpreted literally, it implies that agricultural water use has been reduced from 80 percent to 43 percent with a transfer of agriculture’s use of water to the environment. Reading the news over the past few years, it might have seemed like such a thing happened. It hasn’t, of course.
If this were the case, we would have seen a dramatic decline in agricultural water use since the implementation of environmental laws. We have seen a decline, but it is nothing close to what is implied.
This statement requires some disentangling to separate the facts from the factoids (near-facts which are artfully spun). The roots of confusion lie with the change in how the California Department of Water Resources (DWR) reports water use. Historically, DWR only counted water that was applied for economic uses. Under this scheme roughly 80 percent of water went to agriculture with the remaining 20 percent going to urban uses.
Under the new reporting system, gross water use includes both the applied water for urban and agricultural use, as well as that set aside for flow requirements to meet habitat and water quality needs. This is the source of the second part of the above statement. A more accurate figure is roughly 40 percent agriculture, 10 percent urban and 50 percent environment.
Sounds like the environment is taking all the water after all, even with the new accounting system. But this is a larger total volume of water than in the old accounting system, since environmental water is now added in to the mix. This accounting method is both flawed and misleading.
The method used by DWR sums up all of the instream flows required by regulations. The large environmental number is dominated by flows in rivers designated as Wild and Scenic. Most of the volume that flows down Wild and Scenic Rivers is in the North Coast and includes flood flows, where there is no practical way to recover it for either agricultural or urban use (see blog “water to the sea isn’t wasted”).
When you examine water use within the interconnected network of California that feeds farms and cities, use is roughly 52 percent agricultural, 14 percent urban and 33 percent environmental. While a big difference, even this overstates the environmental take.
When you account based on net water use—meaning water that is lost to evapotranspiration or salt sinks and not returned to rivers or groundwater for alternative uses—this translates to 62 percent agricultural, 16 percent urban and 22 percent environmental. And some of that environmental water is used to keep water quality high enough for drinking.
Source: Author’s calculations using regional 2009 DWR data.
Broad statewide or system wide numbers also mask important local and regional variability in how water is used. As illustrated in the map, based on DWR data, in the North Coast region most water is designated as environmental flow, and it lacks many connections to the statewide water supply system. In the Tulare Basin, almost all water use is agricultural. In the South Coast, water use is overwhelming urban. Regions are often fairly specialized in their water use. Real people and real fish live their lives locally, not statewide.
Patrick Moynihan once famously stated, “we are all entitled to our own opinions, not our own facts.” We need to use water accounting standards that are rational and reflect real differences. There is of course much rhetorical incentive for each group of stakeholders to use water accounting systems where they look unimportant, or their favorite villain looks important – sort of “combat accounting.” On the who-uses-how-much debate, any standard should be net usage of water within the interconnected network of California. All other comparisons simply muddy the waters.
Further reading
Hanak, E., J. Lund, A. Dinar, B. Gray, R. Howitt, J. Mount, P. Moyle, and B. Thompson, Managing California’s Water: From Conflict to Reconciliation, Public Policy Institute of California, San Francisco, CA, 500 pp., February 2011.
Hanak, E., J. Lund, A. Dinar, B. Gray, R. Howitt, J. Mount, P. Moyle, and B. Thompson, “Myths of California Water – Implications and Reality,” West-Northwest Journal of Environmental Law and Policy, Vol. 16, No. 1, Winter 2010.
California Water Plan: http://www.waterplan.water.ca.gov/
Update
Mount, J., Freeman, E., Lund, J. , Water Use in California, Public Policy Institute of California, July 2014
27 responses to “Water—Who uses how much?”
[…] water usage in the state is split roughly 40% agriculture, 10% urban and 50% environment. http://californiawaterblog.com/2011/05/05/water%E2%80%94who-uses-how-much/ Share/Bookmark Is cleantech a service […]
[…] few times). In California, the vast majority of the state’s water budget goes to agriculture (up to 85 percent, depending on whom you ask), and groundwater reserves—the primary source of irrigation […]
[…] of what could have gone to agriculture was diverted to delta preservation. That’s good news for the smelt and six other stupid fish, ten stupid […]
[…] http://californiawaterblog.com/2011/05/05/water%E2%80%94who-uses-how-much/ […]
[…] water use accounts for 10-15% of demand, and while it is not the biggest slice of the pie, it’s good to be as efficient as […]
[…] Valley may spur an earthquake, due to shifting weight loads. With agriculture comprising about 80 percent of the water use in California, this might be another wake-up call for many California farmers to find more efficient water […]
[…] DroughtCalifornia Drought289.3 KPCCCalifornia WaterBlogNational Public RadioUSA […]
[…] DroughtCalifornia Drought289.3 KPCCCalifornia WaterBlogNational Public RadioUSA […]
[…] California Drought California Drought2 89.3 KPCC California WaterBlog National Public Radio USA […]
[…] Broad statewide or system wide numbers also mask important local and regional variability in how water is used. As illustrated in the map, based on DWR data, in the North Coast region most water is designated as environmental flow, and it lacks many connections to the statewide water supply system. In the Tulare Basin, almost all water use is agricultural. In the South Coast, water use is overwhelming urban. Regions are often fairly specialized in their water use. Real people and real fish live their lives locally, not statewide.http://californiawaterblog.com/2011/05/05/water%E2%80%94who-uses-how-much/ […]
[…] Water: Who Uses How Much? […]
[…] Valley may spur an earthquake, due to shifting weight loads. With agriculture comprising about 80 percent of the water use in California, this might be another wake-up call for many California farmers to find more efficient water […]
[…] A large portion of the water being used comes from agriculture. The urban sector uses far less water. However, everyone must lower their water consumption by 25% or face harsh penalties. […]
[…] What accounts for the confusion is a change in the way the state measures its water. Basically, the government used to look at the total amount of water put to economic use, 80% of which went to ag. Now, it also includes the amount set aside for environmental conservation and restoration, which makes for a much bigger total. Under the new formula, agriculture’s take is far short of 80 percent of that larger pie (which accounts for the choir of Central Valley growers kvetching about salmon runs and the Delta Smelt and putting up “Man-made drought” signs up and down Route 99). According to Jeffrey Mount of the Public Policy Institute and formerly of UC Davis’ Center for Watershed Sciences, the real figure is more like 62 percent. […]
[…] you hear a lot of numbers being thrown around, particularly about the drought in California. Some are believable and rational, but others seem almost straight up […]
[…] uses more than 60 percent of California’s water, and recent immigrants don’t tend to have big, irrigated lawns; swimming […]
[…] works for the heads of giant corporations and major stockholders, period. Currently they are using 46% of water to ‘restore wetlands‘! Are they doing this on purpose so they can buy up California cheaply? It sure looks that way. […]
[…] pie charts, line graphs, and car graphs to focus on a key part of telling a story through numbers. A good example of chart use I found was for water and how much people use it in different […]
[…] Mount, Jeffery. “Water-Who Uses How Much?” California WaterBlog. N.p., 05 May 2011. Web. 10 May 2016. https://californiawaterblog.com/2011/05/05/water%E2%80%94who-uses-how-much/ […]
[…] as wild and scenic, which meansthey can’t be dammed without an act of Congress. In a blog post, Mount writes, “Most of the volume that flows down Wild and Scenic Rivers is in the North Coast […]
[…] designated as wild and scenic, which means they can’t be dammed without an act of Congress. In a blog post, Mount writes, “Most of the volume that flows down Wild and Scenic Rivers is in the North Coast […]
[…] designated as wild and scenic, which meansthey can’t be dammed without an act of Congress. In a blog post, Mount writes, “Most of the volume that flows down Wild and Scenic Rivers is in the North Coast […]
[…] as wild and scenic, which meansthey can’t be dammed without an act of Congress. In a blog post, Mount writes, “Most of the volume that flows down Wild and Scenic Rivers is in the North […]
[…] designated as wild and scenic, which means they can’t be dammed without an act of Congress. In a blog post, Mount writes, “Most of the volume that flows down Wild and Scenic Rivers is in the North Coast […]
[…] designated as wild and scenic, which means they can’t be dammed without an act of Congress. In a blog post, Mount writes, “Most of the volume that flows down Wild and Scenic Rivers is in the North Coast […]
[…] https://californiawaterblog.com/2011/05/05/water%E2%80%94who-uses-how-much/ […]
[…] Farmers use by far the most water of any business in California (here’s where to look for the clearest explanation of water use in California), and (2) agriculture produces only about 2% of California’s gross domestic product. Anyone who […]