Highlights Rainwater Harvesting at ARCSA 2005
by Anitra Accetturo
13-15, of 2005 the American Rainwater Catchment Systems Association
(ARCSA) hosted the North American Rainwater Harvesting
Conference in Seattle, Washington. The three-day conference
focused on design, installation, and components of rainwater harvesting
systems featured in presentations and exhibits (see related article
"ARCSA 2005: Focus - Rainwater Harvesting").
first day of the conference was kicked off with an optional tour
of rainwater harvesting systems in the Puget Sound area, featuring
innovative and progressive water harvesting and sustainability
techniques designed and utilized by the city.
City of Seattle, with its abundant rainwater, has proven
itself to be a front-runner in the field of innovative design
and use of rainwater catchment, stormwater runoff reduction, and
sustainability solutions. See
the Spaceneedle webcam for live views across Seattle.
City Hall is a 20,000 square-foot building that was completed
in 2003, and includes a green roof and rainwater harvesting (RWH)
system for toilet flushing and on-site irrigation. These systems
help reduce peak flows from the city drainage system and improve
water quality by reducing the pressures on the city sewer infrastructure.
The RWH collection system can store up to 30,000 cubic-feet of
water in a cistern located in the basement of what was at one
time the old municipal building. Collected rainwater is then pumped
from the basement cistern to restrooms in the newly constructed
City Hall building for use in toilet flushing, as well as irrigation
purposes. Stormwater runoff is expected to decrease by up to 75%
and reduce indoor potable water use by 30%. These measures result
in a significant reduction of stormwater flows and will alleviate
loads into the city's combined sewer system. The building has
also earned a U.S. Green Building Council Leadership in Energy
and Environmental Design (LEED) Silver rating.
King Street Center is home to the King County Departments
of Transportation and Natural Resources. It is a 327,000 square-foot
building that was completed in 1999. Project highlights include
a 16,200-gallon rainwater collection system, 80% of all construction
waste recycled on-site, and 32,000 square-yards of reused/renewed
carpet tile. The King Street Center would use approximately 2.2
million gallons of potable water a year for toilet flushing. With
a 44,000 square-foot roof area for collection, it is estimated
that about 1.4 million gallons of domestic water will be saved
annually, or 64% of the flushing budget for the year.
Environmental Learning Center is a gathering space for
environmental education activities and community meetings. It
has achieved a LEED Gold certification, (the first Gold rating
in Seattle), and serves as a model for resource-efficiency and
sustainable building. Highlights of the building include a 3,500
gallon rainwater collection cistern used for toilet flushing and
stormwater management, solar electric panels provided by Seattle
City Lights Green Power program, 80% recycling or salvaging of
demolition and construction waste, and use of regional materials
manufactured and salvaged locally. Rain barrels were also installed
on-site for irrigation of salmon-friendly native landscaping while
Edge Alternative Project (SEA Streets) was designed to
provide drainage that resembles the natural landscape prior to
development and traditional sewer and stormwater system installation.
This entailed combining engineering concepts and designs with
native soils and vegetation to assist in treating and regulating
stormwater flows. The selected residential block for the pilot
project had to meet specific criteria such as: a street that does
not have existing curbs and sidewalks, located in the watershed
area, and not directly served by the existing storm drain system.
The pilot project began in 2001, and after two years of monitoring,
impervious surfaces were reduced by 11%. Over 1,100 shrubs and
100 deciduous trees were planted, all native vegetation and hardy
cultivars, resulting in a 98% reduction in total runoff volume.
This successful project is now part of the Seattle
Comprehensive Drainage Plan.
is home to many private and commercial rainwater harvesting sites.
The above sites were toured by the attendees of the ARCSA conference
attendees to educate and interest them in the possibilities for
rainwater catchment and from the excitement of those taking the
tour it was a great kickoff for the 2005 conference.
Accetturo is a Water Conservation Specialist for the city of Bellingham,