7.1 Introduction

We have discussed the flow equations so as to understand, both conceptually and mathematically, how groundwater flows in a porous medium. The main equation that we developed and discussed is a partial differential equation that governs flow at a given point under all conditions (assuming that Darcy’s law is valid). In essence, it is the all‑purpose equation that covers all situations. In order to solve this differential equation for a natural groundwater system, we need to apply it to a specific situation and make some simplifying assumptions. One specific situation that the equation has been solved for is flow of water in an aquifer to a well. In this section, we discuss the concepts and mathematics of well hydraulics, or flow to a pumping well.