In this study a different approach has been used to compute the practi
cal equilibrium scour process caused by both plunging and horizontal j
ets when no bed protection was present. Newton's second law of motion
has been applied to a mass of particles of fluid to derive relations f
or the maximum scour depth in the equilibrium phase. The closure probl
em has been solved by applying the Buckingham Pi Theorem in which the
unknowns are, related to material characteristics analogous to the sco
ur relation presented by Schoklitsch. The accuracy of some formulas fr
om literature that calculate the scour depth under jets, such as issue
from pressure gates, flip buckets, and dam spillways, are evaluated u
sing numerous data of both prototype situations and flume experiments.
A significant amount of work from other researchers has been drawn to
gether to calibrate and verify the predictors for the scour depth caus
ed by horizontal jets. Though the predictability of the new relations
to other scour relations has been increased, they have to be used for
a first approximation in studies.