Hi Krasy, so we meet again! Soft bodied lures have been mentioned, but try them without a lead head. Thread a trace through them with a baiting needle & put a circle hook or treble on the end. Out a bead between the hook and the body of the lure. Work them as a jerk bait. If you need depth then pop a swan shot or two on the trace against the nose of the bait. Very popular technique here on Englands Norfolk Broads, and they really do catch, big time. Our Broads are, in some respects, similar to your gravel pit but are then connected to nearby rivers.