Slide 11 of 49
Notes:
Sending rooftop runoff over a pervious surface before it reaches an impervious one can decrease the annual runoff volume from residential development sites by as much as 50%. Some possible techniques to encourage treatment of rooftop runoff on-site include directing flow into stormwater treatment practices (infiltration swales, infiltration trenches, or dry wells), encouraging sheet flow through vegetated areas, or directing runoff to depression storage areas.
Another alternative to managing rooftop runoff is to drain the runoff directly into rain barrels, which can store the water for later use in gardens, yards, or for house plants.