A large amount of sand deposited in the wave-shelter zone of Ohtsu fishing port located in northern Ibaraki Prefecture, Japan, resulting in a difficulty in navigation at the pot entrance. The BG model (a three-dimensional model for predicting beach changes based on Bagnold's concept) ws used to solve this problem. Measures against sand deposition inside the port were investigated and the most appropriate measure found for preventing sand deposition was the extension of a jetty by 100 m at the tip of the west breakwater. The applicability of the BG model to such prediction was confirmed
