The Problem: In order to predict future water level response to well pumpage in large groundwater basins, aquifer characteristics must be known to a reasonable degree of accuracy. Optimal pumping policies can then be developed on the basis of the following criteria: 1) Meet all future water demand; 2) Minimize pumping costs (which are directly related to depth of water level or drawdown); 3) Guard against harmful "mining" of the groundwater resource, with land subsidence and irreversible loss of storage potential as inevitable consequence.