Closing the northernmost lock on the Mississippi River will mean fewer jobs and more costly truck traffic and likely have little impact on Asian carp travel plans.

Those and other conclusions about everything from aesthetics to safety are contained in a just published U.S. Army Corps of Engineers, St. Paul (Minn.) District, draft environmental impact assessment of plans for the Upper St. Anthony Falls Lock. 

The lock and dam at Mile Marker 853.9 in the Twin Cities is scheduled to close by June 10, 2015, thanks to a provision in the Water Resources Reform and Development Act (WRRDA) of 2014. Supporters of the move said it was to protect the waterway from voracious Asian carp. Others said it was a way to get rid of river-dependent businesses and redevelop the area.

The closure will mean a loss of an estimated 84 jobs. For the entire state economy, the number is not significant, the Corps report said, although “to those individuals affected, however, the loss of a job certainly would be substantial.”

Shifting cargo from barge to truck will cost an additional $21.5 million through 2040, the Corps said, citing a Metropolitan Council study. Among the factors involved are “vehicle operating costs, additional highway travel time, the logistics costs of commodity delivery times, and safety and environmental costs of moving the various types of commodities through the state by truck.”

Barge traffic through the lock averaged 755,834 tons annually from 2010 to 2014. Major commodities moved through the lock include sand and gravel, coal, scrap metal and fertilizer.

Closing the lock is expected to add more than 21,000 truck trips a year to the highway system primarily during the workweek, the report said. “Sixty trucks are required to haul the same amount of bulk freight as a fully loaded barge (1,500 tons).”

The impact on Asian carp is less conclusive. Control of the invasive species spreading up the inland waterways has sparked heated debate. “The closest location where actual reproduction of Asian carp has been documented is about 400 river miles downstream of [the Upper St. Anthony lock],” the report said. Carp expansion on the Upper Mississippi “has been relatively slow over the last 20 years,” and the chance for appreciable numbers below the lock that might lock through above it “appears to be low.” — D.K. DuPont