wood strips to hold the outer seams. over lap the tarps, so the top foot is with the wind. stagger your sandbags. 6' 8' 10' down. you can create saddlebags. Great for wind. tie two sandbags together with baling twine/whatever you have and hang off opposing sides of the pitch.

here is a picture of a levee that shows the saddlebags.

http://www.sjgov.org/oes/disasters/photo...lood%20prep.jpg