Have a 20-year old townhouse. In front, the garage is at street level but the family room in back is below grade. There is a sliding door from the family room out to a small yard. Just outside the family room is a concrete pad, with a drain in the center.
Over the years, this drain has gotten slower and slower and in one or two extremely heavy rains, it was unable to handle the onslaught of water and we had some come over the sliding door sill into the family room. It happened again recently.
I popped the top of the drain and found it to be full of small rocks with the interstices between the rocks packed tight with 20 years of accumulated crud so I began scooping out the rocks and crud by hand. Lousy job. I removed about 10, two-gallon pails full of material.
The drain opening is about 6 inches across. As I removed the rocks and gunk, it seems that the hole/drain immediately below the opening is about 9 inches to a foot in diameter. I scooped out dirt and rocks for about two hours and had reached a point about 18 inches down the hole.
As i poked around, I found a pipe, two or three inches in diameter, an inch or two below the drain going off at a right angle. I gave up digging junk out after two hours and turned the garden hose on and aimed it into the hole/drain. It drained faster than I have ever seen it drain in 10 years. For once, something went right.
Questions:
a. What is the proper name for this kind of drain?
b. Should I keep going, removing as much of the crud and rocks as I can?
c. Should I clean the crud off the rocks and put then back?
d. What does that 3-inch diameter pipe going off at a right angle do? When I aimed the garden hose in, the water level never rose anywhere near that pipe yet the water drained immediately.
Thanks a lot for any info; I'm clueless about what my next step should be?
Bob