water, ethanol, and corn

i've been reading again...."Consulting the Genius of the Place: An Ecological Approach to a New Agriculture" by wes jackson...the national corn grower's association action alerts and their propganda about ethanol production...u s weather service rainfall average reports and some information about groundwater use from the ogallala aquafier so lets see if i can make sense of some of the data...a corn crop generally needs 24 inches of mosture during its growing season....that's two acre feet per acre ( the ammount of water it would take to cover an acre to a depth of one foot is an acre foot ) those two acre feet represent 651,702 gallons of water for an acre of corn...a bunper harvest from that acre would be 220 bushels of corn and that corn would translate into 104.940 gallons of ethanol at a rate of 2.77 gallons of ethanol per bushel...that's about 6461 gallons of water per gallon of ethanol ( you have to wonder how much water goes in to hot pockets or mountain dew)...indiana's annual precipitation averages ( there are wetter and drier parts of all the states i'm listing) is 40 inches...illinois 38 inches...iowa 35 inches...nebraska 23.6 inches...kansas 27.84...obviously in bad years or even normal ones some states are going to have to irrigate...nebraska and kansas overlay the ogallala aquafier which this year has had 26.1 cubic kilometers of water removed from it...more than the discharge of the colorado river...a serious overdraft of a water source that will dry up with continued use at those level...kansas and nebraska may go out of the corn business over water...we could talk about g m crops...but then we'd be getting into energy use and petrochemical based inputs on the farm to protect crops that are more vulnerable than those created by old fashioned domestication and i'm not dealing with that right now...just the water use limits corn as a viable source of alternative energy...the corn hacks at the national corn growers will tell you different because they like the way ethanol drives corn prices up...but they are just as biased as i may be and i don't trust them...the figures i find tell me a different story...and as an afterthought, is this more water than is involved in the current production of petrolum based fuels? i know the bp/ammoco refinery in whiting dunps alot of benzine into lake michigan as part of the distilation process...how much water passes through that plant per gallon? more rsearch...stay tuned.