SIMULATED AQUIFER RESPONSE TO THREE FUTURE WITHDRAWAL RATE SCENARIOS
The current model was used to predict the effects of three withdrawal rate scenarios on hydraulic heads over a 30-year period from 1998-2027 and one scenario with withdrawals extended indefinitely until equilibrium conditions were attained (steady-state conditions). The 30-year transient simulation period was segmented into six stress periods of 5 years each. Total withdrawals for each scenario are listed in table 7 with other selected volumetric budget information and hydraulic head altitude data from model cells representative of cone of depression centers for model calibration (1997) and for predictive scenarios. Development of the scenarios was based on information collected from Sparta aquifer water users and managers in Arkansas, Louisiana, and Mississippi, and in collaboration with Arkansas Soil and Water Conservation Commission and Memphis Corps of Engineers representatives.

Each of the scenarios shows hydraulic head altitudes simulated through time. Each begins in 1898 (predevelopment), proceeds through the calibration period of 1997, then predicts hydraulic head altitudes for a 30-year period from 1998-2027 using different withdrawal rates. Scenario 1 is extended through to steady-state conditions.