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1. 2, steps, 3, steps, IJ, Historic-diversion Is teps, 5, steps, 6. Median-diversion time steps, No recharge with current pumping and annual time steps, Median-diversion recharge with current pumping and annual time Median-diversion recharge with current pumping and monthly time recha rge wi th current pumping and monthly time Median-diversion recharge with increased pumping and annual time recharge with maximum increased pumping and annual Those alternatives with annual time steps used elapsed times of either ,100 years or continued unti 1 a steady-state was achieved, whichever occurred 'first. The order of the alternatives discussed in this report follows the Istudy as it was presented during frequent oral progress reports and reflects Ithe questions and desires of interested persons expressed during the study. Several simulations were repeated for some of these alternatives, assuming !different canal configurations, The results of these simulations are pre- lsented in tables but discussions in the text are limited to the configuration :of the ent i re cana 1 sys tem \" i th 65 ponds, I I The first alternative simulated was for no artificial recharge, As noted in table 11, the ~eaver Creek valley aquifer system is currently (1978) lestimated to be in an overdraft condition--pumping plus natural discharge ex- :ceeds natural recharge. Unless pumping is further reduced, water levels wi 11 , 'continue to .decl ine. During 15 years at the current (1978) pumring rate, Ilittle change would occur in the southern one-half of the modeled area but in the northern one-half, water levels would decl ine as much as 15 ft. After '25 years, some areas would become desaturated and some water-level decl ines would exceed 25 ft, In the thirty-fourth year of simulation, the model could no longer compute a solution because there were large areas of totally ~esaturated alluvium, This simulation did not assume any reduction in pumping as water levels dec1 ined, In real ity, less water could be pumped Ifrom wells as water levels decl ined, and thus land would be taken out of ,irrigation; this would progress until a new equil ibrium eventually would be 'reached, i , , . I A set of fIve different artificial-recharge inflows, generated by the canal-distribution model (table 6), were input into the model while maintain- ling pumping at the estimated current rate. Water budgets for each of these ~lternatives under steady-state water-table conditions are summarized in .table 12, For each alternative, the artitificial recharge eventually brings ~ halt to the overdraft condition, The additional recharge to water levels :can be great enough to create a flowing stream, On the other hand, a re- 'charge-discharge system could be designed to bring the system to a steady- ~tate condition where water levels would support pumping but where streamflow rOUld not be supported. 60 _:..:I