Seepage from rivers and natural channels is a serious problem in the Sacramento Valley of California. Impairment of land use occurs along the Sacramento, Feather, Yuba and Bear Rivers as a result of intermittent periods of high ground water or ponded surface water. When channel levels exceed the adjacent ground surface elevation, water moves through and under the confining levels into adjacent lands. If drainage facilities are inadequate, the soil becomes saturated and water often ponds on the surface. The water damages orchards and perennial and annual crops, and prevents working of land, resulting in delays in or prevention of normal planting of annual crops.

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.