For the third scenario, scenario 2 pumpage was used except that pumpage was reduced by 10 percent from that of scenario 2 in a selected area (fig. 25 in report) to represent possible replacement of ground water by surface-water diversion (U.S. Army Corps of Engineers, written commun., 2002) in that area. The 10 percent reduction was applied only to the stress periods ending in years 2019, 2029, 2039, and 2049.
Reducing pumpage by 10 percent (scenario 3) resulted in areas of depressed simulated hydraulic heads similar to those that resulted from scenario 2 and fewer dry cells (figs. 20 and 23 in report). In the 2019 timeframes, scenario 3 (fig. 20 in report) had 3 dry cells compared with scenario 2, which had 10 dry cells (fig. 20 in report). In the remaining three timeframes (2029, 2039, and 2049), scenario 3 (fig. 20 in report) had about two-thirds of the number of dry cells of that in scenario 2. The 10 percent reduction appears to have delayed the development of dry cells by about 10 years as exhibited by the similarities of water levels and dry cells in the 2029, scenario 2 (fig. 23 in report) and the 2039, scenario 3 (fig. 26 in report). Overall, the areas of depressed simulated hydraulic heads are somewhat reduced in this scenario from that using unreduced pumpage (scenario 2).