Originally Posted by Preston H.
Point taken on return flows from agricultural use, even if modern sprinklers don't produce a lot of return flows. But can you tell us what percentage of transmountain water goes to ag use vs. municipal use? I am wondering if it is different in the lower basin states than it is in CO.
Ok Preston so it looks like the exact numbers on this are still being researched by the Bureau of Rec in a supply/demand study that should be completed in the near future.
I got in touch with Brendan, the Program Coordinator for the State of the Rockies Project
and here is what he has to say:
"In the upper basin, Iíd say the large majority of transbasin water is for municipal and industrial use. Some water we dump in the Ark may end up going towards farmers down below Pueblo, but I imagine most ag uses down there are allocations from the Arkís natural flows, not water weíve sent over from the Colorado. Wyoming similarly uses their transbasin diversions in Cheyenne, but I donít think it contributes to ag along the north platte. "
"The lower basin is different though, for a number of reasons. The Imperial Valley is not inside the basin and receives over 1 MAF of water a year from the Colorado. However, Metro Water (LA) takes an equally large, if not larger share of CAís 4.4 MAF. California does use the vast majority of its allocation in transbasin diversions. Arizona is mostly in the basin, so you donít see huge transfers of water out of the Colorado River basin, but the Central Arizona Project geographically reallocates water in a manner thatís inconsistent with whats naturally found. Short answer, in the Lower Basin CA diverts almost all of its water out of basin and Imperial valley is big ag culprit, but LA still has the bigger straw. AZ doesnít have any transbasin diversions, but their environmental engineering for places like Tucson and Phoenix is just as bad."
Hope that helps a bit?