The constant flow of water in rivers and coastal waters tends to erode or "scour" sand or soil away from bridge piers.
(The constant flow of water in rivers and coastal waters; tends; to erode or "scour" sand or soil away from bridge piers) (The constant flow of water in rivers and coastal waters; to erode; )
The constant flow of water in rivers and coastal waters The constant flow of water in rivers and coastal waters
tends to erode
to erode or "scour" sand or soil away from bridge piers