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Water use in US dropped substantially from 2005 to 2010

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As a nation we are using less water, even as our population grows, says a USGS report. This is definitely good news. We are using less water than in 1970.

Water use in the United States in 2010 was estimated to be about 355 billion gallons per day, which was 13 percent less than in 2005. The 2010 estimates put total withdrawals at the lowest level since before 1970.

Thermoelectric power and irrigation remained the two largest uses of water in 2010, and total withdrawals for both were notably less than in 2005. Withdrawals in 2010 for thermoelectric power were 20 percent less and withdrawals for irrigation were 9 percent less than in 2005.

Thermoelectric power is water used to generate electricity from steam turbines, and includes nuclear, coal, natural gas, and concentrated solar power plants. It is the largest single use of water, if a bit deceptive, as the water is often pumped back into rivers where it can be used for other purposes. Agriculture is the second-biggest use of water and again, some of that water seeps back into the the ground and aquifers.

There are lots of caveats. This analysis uses “withdrawals” rather than “consumptive use”. So if a power plant sucks up river water for cooling, that counts as “use” even if most of it is returned to the river. Farmers withdraw a lot, and return some via groundwater seepage and drains. The withdrawal-consumption distinction is really important for water policy, as I tried to explain here.

This big drop also spans the Economic Shitstorm of 2008. Part of the drop could be related to that.

I think a lot of work needs to be done by people smarter than I to sort out the implications of the above two caveats. But those notwithstanding, I think the new data supports the hypothesis (“slogan”?) I’ve been pushing recently: When one has less water, one uses less water. We’re pretty adaptable, we humans.

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