Total grain volumes barged on the Mississippi River are almost 30% below the five-year average due to low export sales and falling water levels, according to a report by the United States Department of Agriculture (USDA) reported by World Grain.

Downbound grain volumes totalled 18.1M tonnes as of 30 September, the USDA’s 5 October Grain Transportation Report said.

From the week ending 8 July to the week ending 30 September, volumes totalled 3.9 M tonnes, 35% lower than the third quarter last year and 53% lower than the previous five-year average.

Almost 60% of US grain exports are transported by barge on the Mississippi River system, which moves grain from the US Midwest to the Gulf region for export, with low water levels becoming a problem in June, two months earlier than last year, the report said.

Barge shipments were hit by historic low water levels last year, which led to below-average annual grain volumes and record high freight rates, World Grain wrote.

More stringent restrictions had been set for draft and tow sizes on various sections of the river system since June, the report said.

According to the USDA, the most severe restrictions are on the Lower Mississippi and Ohio rivers at Cairo, Illinois.

The restrictions mandate loading draft reductions of up to 32% and tow size reductions of 17% to 32%.

Water levels on the Mississippi River at Memphis, Tennessee, were almost 2ft (0.6m) lower than the previous year, the USDA said.

Weekly grain volumes had been down compared to last year in all but two weeks in the first quarter and four weeks in the second quarter, the USDA added.

The largest decline was seen in corn volumes, which totalled 1.5M tonnes in the third quarter (45% lower than in 2022) and 9.1M tonnes in the year to date (32% lower than last year).

Third-quarter 2023 barged soyabeans and wheat volumes heading to the Gulf also showed sizeable drops. At 1.8M tonnes, soyabean volumes were 31% down while wheat volumes, at 522,000 tonnes, were 15% lower than last year.

Spot freight rates have started to increase, but below average export sales and demand for barges had kept rates from rising until August, the report said.

The average third-quarter spot freight rate at St Louis, Missouri, was US$15.92/tonne, 16% higher than last year and 9% lower than the five-year average.

Looking ahead, the USDA said it expected barged grain shipments to pick up in the fourth quarter as the corn and soyabean harvests progressed.

“However, if low-water conditions in the Mississippi River system continue, lack of precipitation may lead to increased restrictions, which would further shrink an already tight barge supply,” the USDA was quoted as saying.

“The rising harvest demand and shrinking barge supply may lead to above-average spot rates that approach last year’s record rates.”

However, early preventative measures could help mitigate conditions that created record-high spot rates seen in 2022, the USDA added.