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l"\ ,,-,..), .") ,loof,. \:J . l.,. gage. The largest difference here is in irrigation. The acres difference is 1655 acres served from the Pine but which reside in the Florida drainage. Colorado accounts for these acres in the Pine River at LaBoca gage. But even accounting for the 1655 acres, the average annual CU rates are different. BOR at about 1.45af/ac, while Colorado is about 1.23 af/ac. Reservoir evap, including stock ponds accounts for the next biggest difference. San Juan River at Farmington BOR average annual (1075-91) Natural Flow is about 50,300af (2.46%) less than Colorado's base flows, The average monthly differences continue to increase as we work downstream, July, August and September are the largest % differences, Reservoir evaporation and irrigation depletions contribute to our major differences. LaPlata River at Stateline BOR average annual (1075-91) Natural Flow is about 17,lOOaf (39.2%) ~ than Colorado's base flows. This station has the largest average monthly differences. The major factor here is CU rates. BOR uses 1.23 af/ac, while Colorado is at 0,62 af/ac, Ray thinks BOR is ignoring the Interstate Compact. Could be. NOTE: CU work done for the Animas-LaPlata Project estimated historic (1929-89) Colorado use at about 0.56 af/ac using inpart historic ditch diversion records.. San Juan At Bluff, DT BOR average annual (1075-91) Natural Flow is about 7l,600af (3.21 %) m than Colorado's base flows. Average monthly difference vary from 1% to -10.5%. BOR natural flows for this comparison were adjusted to match Colorado's analysis by taking Arizona and Utah impacts out of the equation. ********************************************** Unless people have other ideas, the only place I see for BOR to refine numbers is in CU rates. We are possibly low in the Upper San Juan reaches because of forced shortages from the Type I Study, and we are probably low in the LaPlata River drainage because of the Interstate Compact (backed-up by the ALP study). Colorado's reservoir evaporations are so different from BOR's, it would seem something is wrong there and could use some scrutiny. As for monthly variations, the Upper San Juan will be controlled by Navajo Reservoir; and the Animas River, the major downstream tributary, has one of the best monthly comparisons with Colorado. It would seem to me we are ready to begin the next step. John Simons