Oregon Convention Center Rainwater Garden
Location: NE 1st Ave. and Lloyd Blvd.
Stormwater Facility: Rainwater Garden
Facility location : Southwest corner of Convention Center
Type of facility : Vegetated infiltration basin
Date of installation : Spring, 2003
Impervious area managed : 5.5 acres of roof (239,580 sq. ft.)
Size of facility : 2,067 sq. ft. (within water basins)
Design Storm : 25 year
Cost: $450,000 entire garden
The rainwater garden at the Convention Center collects and treats water from 5.5 acres of roof area. The 318 foot long channel simulates a mountain stream with basalt columns and wetland plants like dwarf willow, redosier dogwood, sedges, rushes, and water iris. Terraced cobbled sedimentation basins slow the water, allowing sediments to filter out and increasing time for infiltration. The Oregon Convention Center saves $15,600 on its stormwater bill annually because of this feature. Additionally the rainwater garden helps save water because it does not need to be irrigated as heavily as the rest of the landscaping on the grounds. Surface runoff from the expanded loading dock area is also collected through a separate siphoned inlet then passed through an oil-water separator before the water flows into a 205 linear foot vegetated swale. This filtered water enters the rain garden at the lowest detention basin.
Architect: Zimmer Gunsul Frasca Partnership
Landscape Architect: Mayer/Reed
Contractor: Hoffman Construction
Engineer: David Evans and Associates
Landscape contractor: Teufel Nursery
Stone work: Star Masonry
- City of Portland Business for an Environmentally Sustainable Tomorrow (BEST) Award 2003 Water Conservation
- Certified Earth Advantage building by Portland General Electric
- LEED-EB (Leadership in Energy and Environmental Design for Existing Buildings): Certified in November, 2004 for sustainable practices regarding operations and maintenance of existing buildings. This is the first building in Oregon and first convention center to receive LEED-EB certification.
Original construction: 1990
New construction: 2003, 1 million square feet, $116 million
18 city blocks
Other Green Features
- Reduced urban heat island effect with landscaping and paving.
- Roof is covered with a white membrane to increase reflectivity and reduce heat gain in the building.
- Part of the roof is structured for the additional load of an ecoroof.
- Daylighting used in public areas. Daylighting opportunities in meeting and exhibit spaces are limited due to variable lighting needs of users.
- Low emissivity coating on glass to reduce heat gain to the building.
- Earth Advantage analysis shows just under 2.9 million kilowatt hours in savings ($110,000) each year, 271 kilowatt reduction in peak demand
- Water efficient cooling towers
- Efficient HVAC system
- Low flow fixtures
Operations and management
- Staff receive green trainings twice a year to educate about recycling
- Green team that meets once a month to review projects and ways to operate sustainably