From Kentucky Public Radio's Tony McVeighKentucky lawmakers now have a clearer picture of the economic impact of locks and dams along the Ohio River.There are 20 locks and dams on the Ohio River, eight along Kentucky’s northern border. In terms of tonnage, three western Kentucky locks are the busiest in the nation.Col. Keith Landry, Commander of the Louisville District Corps of Engineers, says Kentucky’s locks have a huge economic impact.“Based on the money the Louisville district spent in the Commonwealth of Kentucky, over a half-billion dollars in personal income was generated, which led to 40-million dollars in tax for the commonwealth," said Landry.And that’s just for fiscal 2008. Col. Landry says the locks and dams not only are safe, cost effective economic engines, they’re green.A barge can move a ton of freight almost 600 miles on a single gallon of fuel. A train can move that same ton 425 miles, but a truck, only 65 miles.