do you mean ten metres ?
if so then its a simple calculation of a hydraulic load on the back of the wall which is shaped like a triangle (thick bit at the bottom) which is why dams are thicker the bottom than they are at the top. Added to this on the levee walls in New Orleans will be the kentic energy of the waves hitting the wall which will exert a different type of force on the wall and far higher than static water pressure.
I havent done this for a while so may be wildy out but I think its about 500KN per metre run of the wall (51 tonnes) acting about the walls centre of gravity, or centroid.
The maths for wave bit are quite complicated really. Lets just say its one strong ass wall
