There were no inspections or instructions to follow, and no economic reason to pay much attention to something that customers won't see. Therefore little or no attention was paid to this very important part of the building process. Usually the problem doesn't show up for several years after all warranties are void, leaving the problem to the homeowner.
Footing Drains Plugged Most contractors connect the roof downspouts to the footing drains.
This is the first mistake. They are there to relieve the pressure against the wall caused by water movement in the ground. Connecting the roof drains often overloads the drains, and most often plugs them with leaves and roof debris, causing even a more serious problem as water builds up in the soil. Call in a sewer cleaning company and have the drains cleaned of debris. Then flood the drains with garden hoses for at least 4 hours to see if water builds up in the drains or shows up in the basement.