Do you have a perimeter drainage system in place? Perhaps it was broken or became clogged. Many time the drainage pipes are not covered properly with landscape cloth and drainage rocks.
Any ideas on this. If this is the root of the problem you might be able to snake the drain lines clean or find the break or plug in the system.
If opening up the backside of the home is not an option you might need to install an interior perimeter drainage system. There is no easy option - sad to say.