Several shots from different angles of men catching tagged smelts and salmon in enclosure with a hand net and releasing them in the river. Several shots from different angles of men at work on a wooden structure, installing nets around it, of men using different techniques to build a footbridge with trestles and boards in river, of bulldozer moving structure into river, of it being pulled in water with two men on it, of men working at the installation of the structure next to footbridge, of two divers working at the fortification and completion of the structure (dam or enclosure?).