Is diverting the first roof runoff worth the extra upkeep?

I’d lean toward a screen for irrigation if the roof is relatively clean and the main concern is leaves or other visible debris. If the roof tends to collect dust or bird droppings, I’d favor adding a first-flush diverter: a screen can catch larger particles but doesn’t remove material carried in the initial runoff. For any use, neither option alone makes the water safe to drink.

That distinction suggests a practical middle ground: for irrigation on a clean roof where nearby trees mainly drop leaves, I’d start with a well-maintained screen rather than add a diverter automatically. If the roof also collects noticeable dust or bird droppings, I’d reconsider and divert the initial runoff; the screen won’t address that material. Either way, the screen still needs regular clearing so leaves don’t obstruct flow.

For upkeep, a screen is the more direct job: clear leaves and buildup when they start restricting flow. A diverter adds a separate point to check - the drain or bypass should be free of debris, and after a long dry spell it’s sensible to make sure the chamber empties and refills as intended. How often depends on what collects on the roof and the device design; neither calls for a universal schedule.

Roof material can matter even when there aren’t many leaves: the surface or its coating may affect what washes into the water. A screen mainly catches larger debris, and a diverter only sends some initial runoff away, so neither guarantees that runoff from every roof is suitable for every use. Are you considering a particular roof material, or is the question more about how to weigh that factor generally?

I’m asking more generally. I’d treat the roof surface and any coating as a separate suitability question: neither a screen nor a first-flush diverter can make runoff from an unsuitable material appropriate for a given use. So I’d check that first, then weigh debris and intended use when deciding whether diverting the initial runoff adds value.

For ordinary garden irrigation, I’d put more weight on roof condition and debris than on adding a diverter by default. For uses involving people or indoor plumbing, I’d be less inclined to treat either device as the key safeguard: I’d first check what treatment and water-quality requirements that use calls for. A diverter can still be one part of the setup, but it isn’t a substitute for those steps.