Basement-Foundation Drainage Issues
We have a 24 year old bi-level home with a full basement (8 foot ceilings). The builder was a high volume company that was known for very average work. The house sits in a generally low area on basically flat ground with a high seasonal water table and silt loam soils. The gutters work fine and drain away from the house.
We have been having a problem with the drainage around the perimeter of the basement slowly backing up into the drain well of the walk-out stairway during heavy rain events. The sump pump works fine (when the power dosen't go out), but the flow into it seems slow.
This evening, as it rained heavily and the water in the well backed up, I took a plunger and went at it. My wife wathced at the sump well down the hall. Initially the flow increased and then slowed as I kept going. As the same time, fine light colored silt came up into the drain well and also into the sump pump well with the trickle. I then stopped and the drain flow into the sump pump well increased significantly and the stairwell emptied.
Can I guess from this that the crushed rock around the plastic drain tile is clogged up with silt? Also, does anyone know if it is standard practice for drains at the bottom of basement stairwells to just connect to the foundation drainage system instead of having a seperate drainage tile to the sump pump? Finally, will we have to dig up this area and redo the drainage to fully solve this problem?
Thanks in advance.