Water Supply Part 4: Water Utilization Narrows Unit Draft

Home Browse Search

new lanes by reserving storage for new lands. Operation Ao. Vii, made for an f 5,000 acre -foot reservoir at liarrows with increased return flows from the Colorado -Big Thompson 'rojeot vas adjusted to reflect shortages that wruld have resulted with only a 625,000 acre -foot reservoir at Marrows. This is summarized in Operation 8L also shown in table 3. The maximum annual shortage is 28.3 percent in 1934 with a maxinum accumulative shortage of 137.1 percent for the reriod. 1531 -1941. By the standards of pert_ :issable shortages as outlined in Volume IV, Chapter 5.3 of the Reclamation Manual, these, shortages excsead both the allowable maximum annual shortage of 25 percent and also the maximum accumulative shortage of 75 percent for the most critical 10-year period. On this basis, the storage space provided by a 675,000 acre -foot reservoir does not pruv a full water supply to the 230,000 :acres of currently irrigat.ed land so a larger reservoir is indicated in order - to insure an adequate water supply to currently irrigated lands until completion of the Blue -South Ilatte Project. Operation ! o. 8C, also summarized in table 3, shows the shortages that woul result with a 625,000 acre -foot reservoir at Narrows plus increased return flows from the Colorado -Big Thompson Project and with the effect of addin7 the increased return flows from an increased im- portation of 64,800 acre -feet annually by the city of Denver. This effects a reduction of the maximum annual shortage from 28.3 percent to 25.2 oeroent with the accumulative shortage reduced from 137.1 per- cent to 104.0 percent. It is not anticipated that the city of Denver will develop the 13