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C::J <-.:l ~ CD (:, ... Eastern MWD 29,620 acre feet, MWD of Orange County 31,470 acre feet, Western MHD of Riverside County 33,713 acre feet, Monroe (1972). With the exception of the San Diego CHA aquaduct #1, these areas will have blended 5~k state water available. In the mid or late 1980's the blend will move to 75% state water. It should be noted at this point that In the 5~k Colorado River water that the TDS could move to 1,230 ppm and to 2,210 ppm in the 25% Colorado River water when mixing with 250 ppm state water without Increasing the TDS In the blend beyond the present 740 ppm value of Colorado River water. The cost to the agricultural economy receiving the blended water will be the Increased price since there will probably be no reduction in yield due to salinity increase above the present value. Even though the Increased price of blended water was politically derived by the MWD board of directors and may not reflect the true cost of obtaining the water, It still remains the actual cost Increase to those farming. The surcharges for the blended 5~k Colorado River water will be, Clinton (1973): 1974-75 $5/ac. ft. 1978-79 $ 9 1975-76 $6 1979-80 $10 1976-77 $7 1980-2000 $10 1977-78 $8 In the 75% state water blended the increased charge would be $15 per acre foot as presently planned, Clinton (1973). The study of yield effects of Increased salinity In the Pacific Coast area then narrows to the region served by the first San Diego aquaduct with a capacity of 190 cfs, It should be noted at this point that the second San Diego aquaduct has pipeline 3 with a capacIty of 250 cfs and pipeline 4 with a capacity of 380 cfs. The pipelines 3 and 4 will have blended state water available in 1975. As presently planned pipelines I and 2 of the first aqua duct are to have Colorado River water exclusively until 1980-1985, Montgomery (1974). The four preferred filtration distribution studies suggested by SDCWA, Montgomery (1974), all Indi- cate that pipelines 1 and 2 will receive water from Skinner plants which would be blended water during the second phase of construction 1980-1995, Montgomery (1974). Metropolitan Water District of Southern California indicates plans to supply blended water to pipelInes 1 and 2 by 1987-88 which Is the same time that the blend will go to 75% state water, Clinton (1973). The data developed in this study of yield decreases from increased salinity In the Colorado will apply only to unblended water. The assumption made is that the Irrigation water Is unsoftened Colorado River water. Mean yields for the San Diego County area were obtained from the Agricultural Commissioner Reports 1968-73, Little (1968-73), and are shown In tables 46 and 60. Table 46 showing the partitioning of acreages of crops into three permeability 46 .