Scour is the consequence of the erosive action of flowing water, which removes and erodes
material from the bed and banks of streams and also from the vicinity of bridge piers and
abutments. Local scour downstream hydraulic structures may cause damage or complete
failure of these structures, so minimizing this phenomenon is very important. The study was
based on an experimental program included 144 tests. These tests were carried in a
rectangular flume with sills fixed in the Perspex floor of flume. Three cases of sill
arrangements were included, no sill, single line sill and fully silled floor. Different heights of
sill 2 cm, 4 cm and 6 cm, different positions at 0.4, 0.5, 0.6 and 0.7 of floor length were tested
under different flow conditions. The experiments showed that for most considered values of
sills heights and position, the value of Hd/Lf = 0.04 gave the smaller values of scour
parameters, while the value of Hd/Lf = 0.013 gave the higher values of scour parameters. Also,
it was noticed that for most considered values of sills height, the case of fully silled floor
gave the smaller values of scour parameters.