Jared Soares | The Roanoke Times

The Army Corps of Engineers is adjusting a flood barrier along the Roanoke River, seen here from the greenway on Monday.

Officials from the U.S. Army Corps of Engineers said Monday that because of lessons learned from Hurricane Katrina and flooding in the Midwest last year, they will be modifying construction already done on part of Roanoke's flood control project.

The work, scheduled to take place over the next few months, focuses on strengthening "Training Wall 298," which runs along the Roanoke River between Franklin Road and Jefferson Street Southwest, a main trouble spot during major flooding in the past.

Army Corps officials said the work will be focused on two kinds of spots along the wall:

• Points where there is a transition from concrete to the earthen levee. These spots will be shielded by either a concrete pad or stone erosion protection, also known as riprap.

• Portions on the rear of the flood wall that would be exposed to rapidly rising water on the upstream end. The Army Corps said it intends to shield the earth embankment below the wall with concrete pavers.

Figures for the cost of the modifications were not available Monday. The cost of the entire Roanoke project, which began in 2005 and will run the length of the river within the city limits when it's finished, has been estimated at $65 million -- the large majority to be paid by the federal government.

"We looked closely at levees and I-walls nationwide, and identified some design weaknesses that were a factor when these structures could not stand up to severe flooding," said Greg Griffith, who leads the Army Corps program to study flood damage reduction structures in this region.

According to Griffith, the work should begin later this month and should be complete, minus some landscaping, by spring.

For more information: www.saw.usace.army.mil/Authorized_Projects/Roanoke/Main.htm.