#TD201703 Temporary Downspouts

During the later stages of construction, the majority of the lot’s acreage is covered by an impervious roof. This area can receive hundreds of gallons of stormwater during rain events. Runoff from most roof surfaces is relatively clean and generally does not require water quality treatment. Temporary downspouts can be used to discharge stormwater from roofs to drains, which helps prevent soil erosion in disturbed areas and eliminates retaining water onsite.

Downspout water should be drained into street gutters to flow through additional BMPs (chevrons, filter fabric, etc.) and then into drains, rather than being discharged to drains directly. Temporary downspouts should be installed as soon as gutters are poured and removed only after the disturbed area is stabilized. Splash blocks placed underneath downspouts can also help prevent soil erosion.