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<br />column is also used to document the horizontal <br />locations of the two cross section stakes ("S") <br />and any rocks ("R") or other features that may <br />have an impact on the discharge measurement. <br />In streams with uniform bottom profiles <br />(i.e., sand, cobble, etc.), channel geometry and <br />discharge measurements are taken at fixed <br />intervals within the wetted portion of the <br />channel. The interval is varied in streams with <br />boulder substrates to more accurately reflect <br />changes in the velocity distribution with <br />changes in channel bottom profile. The stream <br />discharge measurement is divided into a <br />minimum of 20 to 30 discharge cells, depending <br />upon wetted stream width, with a minimum cell <br /> <br />width of 0.3 feet. Sufficient measurements are <br />taken to ensure that no more than 10% of the <br />total streamflow occurs within a single <br />discharge cell. Horizontal and vertical <br />distances are taken from the suspended tape and <br />recorded to the nearest tenth of a foot. Stream <br />velocity (ftlsec) within each cell is averaged and <br />recorded. <br />The bottom of the "Discharge/Cross <br />Section Notes" section is used to summarize the <br />discharge measurement. Space is also provided <br />to record the names of the persons responsible <br />for the field data calculations, the staging pin <br />reading, and time at the end of the stream <br />discharge measurement. <br /> <br />-7- <br />