This chapter describes some common techniques for the measurement of water levels, drawdowns, and discharges. An efficient field work requires experienced personnel, funds, and time. Sometimes any one of these three requirements may put a restriction on the field activities. The best field work is the one during which the optimum amount of these sources is used to achieve a specific purpose. Simple hydraulics structures are ideal pieces of instruments for discharge measurements if the water passes through them in critical conditions. Field experiences have shown that the recovery period is invariably longer than the pumping period. During field studies a common difficulty in discharge measurement is that the leading pipe from the well either branches into many small pipes supplying water to different agricultural lands or to a common reservoir from where the water is distributed by means of many uncontrollable outputs.