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<br />International Agreements With Mexico <br /> <br />The CRSM was programmed to deliver the required flows to Mexico as stipulated <br />in United States-Mexico agreements. Therefore, 1850 x 106 cubic meters <br />(1 500 000 acre-feet) were always delivered to Mexico, but water diliverl~d to <br />the CAP and MWD in California could be reduced. With NWM, the minimum water <br />del ivery yearly to MWD after' 1991 was 678 x lOb cubic meters (550 000 aClre- <br />feet). After 1991, the minimum water delivered yearly to CAP was 493 x <br />100 cubic meters (400 000 acre-feet). With TBWMOD, the minimum water <br />delivered yearly to MWD remained at 550 000 acre-feet but the minimum delivery <br />to CAP was 1048 x 106 cubic meters (850 000 acre-feet). <br /> <br />During the 1991-2020 period, more than 3700 x 106 cubic meters of additional <br />water (3 000 000 acre-feet) were delivered to MWD with TBWMOD, while oveJr an <br />additional 14 802 x 106 cubic meters (12 000 000 acre-feet) were delivered to <br />CAP. <br /> <br />Flow Response <br /> <br />Based on the 1952-1971 virgin flows into lake Powell, the overall yearly <br />incremental increase estimated using TBWMOD flow was 9.8 percent. <br /> <br />The flow into lake Powell, without weather modification and with TBWMOD <br />including suspensions, is indicated in table 5. Potential increases are <br />listed in the last column. <br /> <br />The average percent increase attributed to precipitation enhancement after <br />running the flows through CRSM was 14.1 percent. The actual magnitude of <br />the historical source increment used in establishing the coefficients was <br />1622 x 106 cubic. meters (1 315 000 acre-feet). This level was reached on a <br />year to year basis as shown in table 5. Thg year-to-year range of flows at <br />lees Ferry with NWM ~aried from 10 152 x 10 cubic meters (8,230,000 acre- <br />feet) to 16 157 x 10 cubic meters (13 099 000 acre-fee5). TBWMOD flows at <br />lees Ferry varied from a low and minimum of 10 152 x 10 cubic meters <br />(8 230 000, acre-feet) to a high of 17 926 x 106 cubic meters (14 533 000 acre- <br />feet) as depicted in figure 4. <br /> <br />Reservoir Response <br /> <br />Reservoir response was examined for lake Mead and lake Powell. Water was <br />transferred from above the dams to below the dams by three methods: Through <br />the powerplant, spilled over the top of the dam, and passed through the <br />diversion works but not through the powerplant. <br /> <br />In the modeling .work done there were no spills at Hoover Dam during the <br />1991-2020 period with NWM or TBWMOD. Spills occurred with TBWMOD at Gle~n <br />Canyon Dam in 1998 and 2019 with 1110 x 106 cub i c meters (900 000 acre--feet) <br />and 146 x 106 cubic meters (119 000 acre-feet), respectively. <br /> <br />Flows through the diversion works were specifically examined in the mode~l;ng <br />work. Flows which passed through the diversion works at Glen Canyon DgfTI in <br />9 specific weather modification years amounted to a total of 6763 x lOb cubic <br /> <br />12 <br />