Great Lakes Assurance Program Verification Act of 2013 - Amends the Food Security Act of 1985 to require the Secretary of Agriculture (USDA), in consultation with the Great Lakes States, to establish a Great Lakes basin initiative for agricultural non-point source pollution prevention.
Gives funding priority to producers that participate in a state verification program.
Defines "Great Lakes State" as Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, or Wisconsin.