Farmers, lawmakers and transportation leaders applauded last week’s announcement by the U.S. Army Corps of Engineers that the agency plans to invest $829 million from the re­cently passed federal infrastructure bill to modernize critical portions of the Mississippi River transportation system.

The Corps announced it would target most of those funds, or $732 million, to replace Lock and Dam #25, an 83-year-old structure near Winfield, Missouri. Farm groups and Midwest lawmakers have highlighted the...