the structure can be determined from a known dis-

All of the curves shown in figure 7-3 were devel-

charge and allowable head or width of chute by

oped with the radius of an abutment equal to three

using the charts provided in figure 7-3. The curve

times the width of the chute. If it becomes

with D=O is for a level approach to a drop. The

necessary to increase the radius of the abutments

following equation can be used to determine the

because of upstream embankments or other rea-

discharge at given head and chute width when no

sons, as will probably be the case for smaller

drop is provided.

chutes, the equation for D = 0 should be used for

design since the radius of the abutments will have

little effect on the discharge.

Q = 3.1 W H 1.5

(eq 7-1)