Gutters should be kept clean and debris-free to maintain the longevity of the gutter material—clean gutters dry out after a
rain faster and dry gutters last up to three times longer than
wet gutters, which equates to a significant cost savings. The
Uniform Plumbing Code has an appendix dedicated to rainwater
systems, with guidelines to size gutters, downspouts, and lateral pipes. The applicable plumbing code should be reviewed for any design of rainwater conveyance systems.
To keep leaves and other debris from entering a rooftop rainwater harvesting system, the gutters should have continuous leaf screens made out of one-quarter-inch wire mesh screen in a metal frame or an equally efficient product covering the entire length of gutter. Installing leaf screens will help reduce a rainwater harvesting system’s maintenance, eliminate flammable material from the roof area,reduce mosquito breeding habitat,and eliminate the need for
frequent and potentially hazardous use of a ladder to clean
the gutters.O(∩_∩)O谢谢（请不要把软件直接粘过来了...）