The electric barrier will be built in the Chicago Ship and Sanitary Canal near Romeoville, southwest of Chicago. The canal connects the Great Lakes and the Mississippi River.
The barrier will be built where a temporary one was put up three years ago to determine if the technology could block the route of the voracious carp.
Last week, Congress authorized nearly $7 million for construction of the barrier. Illinois and other states are also chipping in.
EPA Administrator Mike Leavitt said Wednesday the barrier will be completed next April. Experts say the carp could devastate the ecosystem and endanger fishing industries if it gets into the Great Lakes.