Your home generally comes with a single line of defense against groundwater- an exterior French drain system. This drain is designed to naturally drain water away from your home, and this can work for many years without a problem.
French drains count on gravity to drain properly. In some cases, the drains are not installed to slope downwards, and they fail to naturally drain water away the way they were intended. In fact, in some cases, French drains will run around the house and not drain anywhere at all!
A French drain is simply a round tube of PVC pipe sitting underneath a bed of gravel at the base of your foundation. Filter fabric is sometimes installed on top of the stone to keep out sediment, but that begs the question: if the drain can clog, can't the filter fabric clog as well?
When dirt and sediment begins to clog the system, there is no system in place to easily clean it out. In fact, the only way to service an exterior French drain is to dig back down to the foundation and either replace the clogged drain or attempt to unclog it.
To replace or service your exterior French drain system, you yard will need to undergo exterior excavation. Usually done with heavy machinery, this requires the entire exterior of your home to be dug out. Everything along that exterior- including shrubbery, gardens, sidewalks, porches, steps, and all other landscaping in the area will need to be removed while the work is done. Mounds of dirt will be laid in the yard from the excavation, and in the end, the system that's installed will be the same one that has failed you already. And a year after the soil has been backfilled again, the earth will settle, and someone will need to return to regrade the soil so water does not pool around the foundation.
How to Fix a Wet Basement
If exterior drains worked, then basements wouldn't be flooding nearly as much as they do. The way to keep a basement dry is to waterproof the basement from the interior of the basement wall, where it the system can easily be accessed if it ever needs to be serviced or repaired. A basement sump pump should be installed to pump the water out of the home.
These systems are designed to keep your basement dry all the time. Click to read more about basement waterproofing with an interior drain and a sump pump.