Blue Roofs


Blue roofs are non-vegetated point source controls that detain stormwater. Blue roofs have the added benefit of reducing the urban heat island effect and are generally less costly to install and maintain than the more widely known green roof. Modular gravel filled watertight trays (open to the atmosphere) allow water to pond temporarily until the water attains the height of the tray and overflows and drains off the roof at the existing roof drains. Since roof waterproofing is essential, older building may need to have roofs upgraded or repaired before installation of the blue roof system.

Part of Solution

  • Addressing Flooding with Green Infrastructure

  • Photos

    • Feature green ps118 wide