Energy Beets?

I see now there is a push in North Dakota on growing energy beets for ethanol production rather than corn.  The pitch:  Energy beets:  help the soil in that they use less nitrogen than corn; are tolerant to saline soils; deep rooted so they mop up nutrients escaping from shallow rooted crops; require only 1.5 gal water to produce 1 gallon of ethanol compared to corn's 2.5 gallons; produces twice the ethanol per acre than corn; and irrigated yields are 41 tons per acre.

What the article I am reading never says is how much irrigation water it takes to grow a 41-ton per acre crop.  While I can appreciate the fact that the processing water is significantly less for beets than for corn, this has never been the real issue for me as a water manager.  What is the issue is the irrigation water requirement - which for corn, is significant.  I suspect it's considerably more significant for beets, but I've looked for about an hour now and nobody's fessin' up to how much water it does take. This likely means it's a boat-load! 

I guess one could argue that even if beets take twice as much irrigation water as corn, the studies report you only need one-half the acres of beets for the same amount of ethanol produced from corn.  This could be good, right?  At least no worse!  But in the business world I'd be very surprised if the ethanol production (economic returns) won't be maximized if the land and water are available.  Besides, these guys are talking about pretty significant new acreages of beet production.  My guess is that in North Dakota water conservation is not very prominent on the radar screens of those promoting ethanol production from beets.   And this is fine - if you've got the land and water.  But, if water conservation is important, or necessary, to you, looks like it'll have to happen some other way if you jump on the beet ethanol wagon.