I have a 90 year old house with a basement that floods when the ground water rises too high(about twice a year). I cut through the floor recently to install a sump pump and discovered an existing perimeter drain of clay tiles. I assume that this drain had an outlet running to daylight at the lower (back) side of my house, but over the years the end of it would have been buried. I am wondering if anyone can tell me (1)if i am correct and the standard construction techniques back then would have, indeed, run the tiles out the lowest point under the footing and run to daylight and (2) if these clay tiles would still be usable--there is no evidence of any gravel or anything around these clay drain tiles that would prevent them from silting up. (indeed the section I dug up was pretty full). The soils are pretty tough and digging along the foundation wall to find the outlet will be a big investment. Anyone have experience with these old systems? Thanks for any help.