Is the NATIONAL Book Award? If yes, then list it as national.
However, if it's an award that they just give at your school, then you would list it as local.
See if you can search for that award on the internet, if you can, you'll be able to figure out if it's a national or state award.
But like I said, if it's something that is only offered at your school, I think local is the best option.