River conditions may have played a part in a much slower shipping season on the upper Mississippi. New numbers from the Army Corps of Engineers show that tonnage getting locked through at both locks 7 and 8 was down significantly from last year. 12% less than last year at Lock and Dam 7 at Dresbach. 14% less at Genoa. The shipping season was hampered by a slowdown due to flooding into July and a drought that lowered river levels after that. A lack of grain demand overseas also apparently impacted shipping.