Download Full Text (1.4 MB)
A suite of model simulations were run to estimate discharges at Barton Springs under alternative pumping scenarios and alternative initial conditions. Fifteen simulations were completed that involved 3 different initial conditions (low-, intermediate-, and high-flow conditions described in the Methods section) and 5 pumping scenarios with annual averages of 3,847; 4,469; 5,437; 6,796; and 16,311 acre-feet per year. The purpose for these scenarios was to evaluate the effect of antecedent conditions and pumping on spring flow. Each of these scenarios included 342 7-year simulations extending from 1648 through 1995 for a total of 28,728 months. Results for the simulations showed that simulated discharges for Barton Springs at or below 11 cubic-feet per second (equivalent to the estimated minimum discharges during the 1950 to 1956 drought-of-record) occurred at a relative frequency of 5 percent using starting heads at low-flow conditions and an annual average pumpage of 6,796 acre-feet per year with the 2002 well spatial distribution. The 2002 well spatial distribution is assumed to be comparable to current groundwater withdrawal rates. Discharges from Barton Springs at or below 9 cubic-feet per second occurred at a relative frequency of 4 percent, followed by 2 percent or less for 7, 5, and 3 cubic-feet per second. The relative frequency for simulating discharges at or below 11 cubic-feet per second decreases to 0 percent using an annual average pumpage of 6,796 acre-feet per year with starting heads at intermediate- or high-flow conditions.
Barton Springs, Alternative Pumping, Groundwater Model
Report GAM Run, Vol. 9, no. 19 (2011-06-01).
Hutchison, William R. and Hill, Melissa E., "Groundwater Model Runs to Estimate Monthly Average Discharge from Barton Springs under Alternative Pumping Scenarios Under Alternative Initial Conditions" (2011). KIP Articles. 2273.