Hey Mr. Green,

The drought in the West seems to be on everyone's mind—our main concerns being yard watering, shower length, and when to flush. However, when I look at the huge number of things being consumed, I wonder how much water is needed to produce nonessential items. Outside of household water, what uses require the largest amounts of water?

—Kim in San Anselmo, California

It may come as a, um, shock, but your household electrons are major water guzzlers. Of the 355 billion gallons of water drawn each day in the United States (which does not include water for hydropower use), 161 billion goes to thermoelectric power plants, according to the U.S. Geological Survey. Granted, some of this is salt water, and much of it is returned to the sources from which it was drawn. The National Renewable Energy Laboratory estimates that an average of two gallons of water are evaporated for every kilowatt-hour of electricity produced by thermoelectric and hydropower plants. That translates to almost 20 billion gallons lost.

It's yet another reason, besides reducing greenhouse gas emissions, to turn off your lights, gadgets, and air conditioners.

Industry uses around 5 percent of the water supply. Irrigation is by far the biggest single use, at 115 billion gallons a day, while fish-farming takes more than 9 billion gallons. So your food requires beaucoup H2O. There's a load of misinformation about how water can be saved by personally giving up foods like almonds or hamburgers. Doing so may be good advice for anybody requiring weight loss or Lenten penance, but it disregards economic and agricultural reality: 70 percent of U.S. almonds are exported, and beef can be raised in locations and on crops that don't require irrigation. So the best answer to drought is to get involved in water-use policy and seek reforms in where and how irrigation is done. 

In the meantime, let the lawn go brown and the car get dusty, keep shortening the showers, replace water-wasting toilets and appliances, and flush judiciously. —Bob Schildgen