Rooftop downspouts are directed to vegetated areas rather than to impervious driveways, gutters and eventually into waterways.
Benefits & Problems Addressed
Reduced pressure on sewer systems: On-site capture reduces the amount of rainwater that must be managed by sewer systems and eventually drained into waterways.
Reduced pressure on receving waterways: Rooftop runoff is treated and handled on an individual building site, reducing the amount of polluted runoff making its way into streams and lakes.
Inexpensive stormwater fix: Modifying downspouts to vegetative areas rather than a driveway is typically an inexpensive procedure compared to other larger scale management practices.
Tips & Techniques
Vegetated receiving areas: Typical receiving areas for disconnected roof runoff include lawns, gardens, and other existing landscaping such as shrubs.
Soil & landscaping considerations: Soil amendments can be used to increase soil permeability if necessary.
Hot Buttons: Downspouts must discharge into suitable areas away from foundations or neighboring property.
Portland OR US Downspout Disconnection Program
Toronto Downspout Disconnect Instructional Video
Water Environment Research Foundation Livable Communities Toolbox