The Free On-line Aquaculture Dictionary
Scouring Velocity
Material
Velocity m/sec
Soft earth, river mud, silt
0.08
Clay
0.15
Sand - Fine
0.21
Sand - Coarse
0.24
Fine gravel
0.30
Pebbles (25mm diameter)
0.60
Stones (75mm diameter)
1.50
Boulders (300-450mm diameter)
3.00