In scenario 2, pumpage was increased according to current water-use trends to simulate likely demands in the future. A regression was developed to determine a trend in the rate of increase for each county using water-use data from 1988 through 2000 (Holland, 1993, Holland, 1999, T. W. Holland written commun., 2002 U.S. Geological Survey). Pumpage for each county for future years was estimated from the regression. This trend was applied to the 1997 pumpage to supply increased pumpage for successive stress periods to a maximum value of 1.25 times the estimated pumpage for each county in 2000.
The simulated water-level map (fig. 23 in report) and the animation for Scenario 2 indicate enlargement and deepening of previously described depressed potentiometric surface areas and the presence of dry cells in Desha County in 2019. A total of 10 dry cells appears in the 2019 timeframe. The pumpage-induced area of depressed simulated hydraulic heads in Desha County elongates further to the southeast and northwest into Lincoln County. An area in southern Desha County that was previously greater than 50 percent saturated formation thickness drops below the 50 percent saturated formation thickness level to a total thickness of 11 to 30 feet in 2019.