It depends on where the wall is built in relation to the border. If the wall is built some distance away from the border, then landowners will have property they can only access via Mexico and crossing the river. Therefore that land's value will be impacted and the owner will have to be compensated for any land that lost considerable value due to the building of the wall.
Landowners who had, for example, I-70, run through their land had to cross on bridges like the rest of us.
P-pull up your big boy pants T-tex. It’s h-happening.