On Mon, 27 Dec 2010 04:28:40 -0800 (PST), allthings5
wrote:

In OP's case, they probably tied to the footer drains, which probably
have failed. If no basement stairwell, maybe their idiot previous
owner directed the downspouts into the footer drains. (Mine simply
shoved pipes straight down at the corners of the house, and he was
puzzled why basement was damp all the time.)

--
aem sends...

Thanks aemeijers,
I thought it might be the downspouts, but then I remembered that I
disconnected them (city regulation for the past five years or so), and
they just water the lawn away from the foundations.

Don't know how you would get leaves and soil in a basement floor
drain.
Can leaves blow in when an outside door is open?

Anyway, the floor drains I'm familiar with tie into the sanitary
sewer.
There's a p-trap to keep gas from coming out.
I had a clogged one in my old house the plumber couldn't snake.
Was plugged up when I bought the house.
He had to jackhammer the floor around it out to get the trap out, then
he got it clear, refitted, and poured new concrete.
Cost me almost nothing because he my neighbor's son and wanted me to
work for him - so I'm not recommending that.
I think somebody had dumped concrete or plaster in that drain which is
why it couldn't be snaked.
I wanted it working.
In your case it might not be worth a lot of expense clearing it unless
you have a reason.

If you don't have a collapsed tile, you might try to snake it until
you get it clear, pouring water in while you do it.
It could be that common basement dirt/dust has built up in there over
the years because it hasn't had any water run through it.
That could be cleared with some snake work.
Just guessing, since you didn't provide any real history or how the
drains are designed.

--Vic