Typical gaging stations are illustrated in Figure 2.31 and 2.32. In many gaging stations, a
manometer and gas under pressure bubbling into the stream are used to measure stage instead
of a float, well and pipe intakes (Figure 2.33). The stage versus time is recorded by pen on
paper, or electronically on tape, or both. Figure 2.34 illustrates a stage versus time chart. Also,
at many stations the stage is transmitted over phone lines or satellite to a central location.
Discharge is measured using a current (velocity) meter by wading at low flow and from a
cableway or highway bridge at high flows. The procedure for an actual current meter
measurement is described in the next section. In many cases, large flows are measured by
indirect methods such as a slope-area measurement using Manning's equation; however, the
preferred method is to use a current meter measurement.
Figure 2.31. Gaging station well and shelters (from Buchanan and Somers 1968a).