Part of any roof inspection checklist should be a roofing drainage inspection. The roofing inspections should check that the roof structure provides for positive drainage to eliminate ponding water whenever possible. The weight of ponding water may deflect the decking and framing members, causing damage to the structure and the roofing system. Proper roof drainage is a very important item in a maintenance program. These structural issues should be addressed with your engineering and architectural advisors.
Drains should be kept clear, and any debris that may clog a drain such as tennis balls, baseballs, beverage cans, etc. should be removed during each inspection. Every drain should have a clean "leaf" grate present to prevent clogging of the drainpipes.
A roof inspection in the late fall should also include the removal of leaves. A clean industrial broom can be used to sweep the leaves from the drainage path(s).