Monday, March 21, 2011
The Way I Figure it...
Corn in our area (Northwest Kansas) will take an average of 150 AF of water to grow an average of 225 bushels on a 120 acre circle - a very typical arrangement - here. But only about 80% of that pumped water is consumed in the growing process (the rest returns to the aquifer system - yes, this is the consumptive water use mantra AGAIN!!) This means that 48,877,650 gallons of water are pumped, of which 39,102,120 gallons are used. With our average yields of 225 bushels of corn per acre, this means that 27,000 bushels of corn are produced for the 39,102,120 gallons of water. This is 1,448 gallons of water for each bushel of corn.
Yeah, I know the real water footprint of ethanol production is even more complicated than this, but it seems to me to be an unsolvable argument when no one has any idea what the production choices will actually be otherwise. These new production choices will be the key to making our water supply problems better or worse, and they'll vary from place to place based on local economics and regulations.