On May 4, 12:00*pm, Steve Barker wrote:
Anything that can get through the hole at the top will pass through the
downspout. *no screen is recommended or needed.

In my neighborhood (built in the 1920's), all the downspouts run into
the ground and connect to the storm sewer system in the street. So I
need to keep stuff out to prevent clogs in the underground long
horizontal runs.

I have downspout screens that look like this:

http://www.guttersupply.com/p-screen...rs-round.gstml

Ken