Dupuit-Forchheimer approximation may underestimate groundwater flow to San Joaquin River

Abstract

Based on the commonly used Dupuit-Forchheimer approxima- tion, estimates of groundwater contributions to flows in the San Joaquin River may be too low. Why? Because the vertical ground- water flows through the base of the channel have been neglected in es- timates. Scientists found that flows have been underestimated by as much as 25%; such flows may de- grade river water quality more than anticipated. The findings suggest the need to closely monitor sub- surface runoff. A new look at the estimates is important to the devel- opment of water/salinity manage- ment plans.