On Sun, 01 Jul 2007 17:09:53 -0700, "
wrote:

If downspout is clogged, wouldn't the waterflow spill over to the
sides completely rather than just that sagged/bent part? I just

It would come out the low spot, and the more there were, the .

checked the downspout and it does have some debris, but the water
still flows out pretty well.

Well I don't know what pretty well means. I would wait until it is
happening again and look. There is no substitute for direct looking.

You'll be able to see if it is backed up at the downspout, if it is
near overflowing everywhere. The water in the gutter will be almost
level so you'll be able to see without a 12 foot straightedge how much
it is sagging. Although you should use a 3 foot straightedge too.

You'll be able to run the garden faucet at the same time it is
raining, and if it swallows both together without backing up, when it
is already overflowing at the bump, then it is not the downspout.