The document describes a raingarden at the Oregon Convention Center in Portland, Oregon. The raingarden collects up to 7,500 gallons of stormwater runoff from the roof and filters it through terraced basins containing plants before releasing cleaner water. It provides both stormwater management and an attractive landscape feature. A similar project in Seattle called SEA Streets uses bioswales and native plantings along curved, narrow streets to naturally filter stormwater and reduce impervious surfaces.

1. OREGON CONVENTION CENTER
RAINGARDEN RAIN
photo credit: www.portlandonline.com GARDEN
Ashley Thorner
Raingardens
Urban + Residential
URBAN RAInGARDEn
landscape architect : MEYER/REED
DOWnTOWn PORTlAnD, OR
2003
The Oregon Convention Center features a “raingarden” which collects as
Downspout much as 1,000 cubic feet of stormwater runoff (that’s just under 7,500 gal-
photo credit: meyer/reed.com lons) from the 5.5 acre roof area. The raingarden is a 318 ft. long channel
that simulates a mountain stream with basalt columns, wetland plants,
native vegetation and grasses. The raingarden consists of terraced cob-
bled sedimentation basins that act to slow the water, allowing sediments
to filter out and increase time for water to infiltrate into the ground. The
water course is lined with 12 tons of Iron Mountain flag-stone and 90 tons
of river rock, and vegetated with Common rush, dwarf willow, red osier
dogwood, sedges, Yellow Flag Iris, Siberian Iris and water Iris. These
plants help to reduce the total volume of storm water runoff as well as help
Raingarden
photo credit: Portland OR tourism; www.pova.com to filter out pollutants and to stabilize the soils. The garden is not only an
attractive addition to the exterior of the Convention Center, but also re-
turns water to the city sewers cleaner than it came in.
The raingarden at the Oregon Convention Center in Portland
provides an aesthetic urban demonstration that integrates
stormwater filtration gardens as a visitor attraction. The
raingarden mimics nature’s processes of retaining and
cleansing water before it is released back to the Willamette
River.
for more information:
www.portlandonline.com, Portland Bureau of Environmental Services
http://www.mayerreed.com/occl.html, Meyer/Reed Landscape Arch. profile
http://www.mayerreed.com/occl.html
http://www.pova.org
Raingarden
photo credit: Portland OR tourism; www.pova.com
RAINGARDEN

2. SEA STREET: street-edge-alternative
SEA Streets,bioswale
photo credit: City of Seattle;
RAIN
www2.cityofseattle.net
GARDEN
Ashley Thorner
Raingardens
Urban + Residential
SEA STREETS: nATURAl DRAInAGE
SEATTLE PUBLIC UTILITIES
NORTHWEST SEATTLE, WA
2003
Bioswales are along both sides of the road with grasses,
sedges and rushes that filter the pollutants out of stormwater.
Designers followed the concept of “right plant, right place,”
SEA Streets is a Seattle Public Utilities and natural drainage project located in
selecting non-invasive species that can survive with little main-
northwest Seattle. it is a prototype project designed to provide drainage and infil-
tenance in our local climate. Trees with smaller root systems fit
more easily within the right-of-way; plants that thrive in wet- tration that mimics the natural processes.
lands have been placed in the lower, moist areas of the storm-
water swales and ponds. SEA Street breaks the 150 year convention of standard street design, using nar-
row curbs, curved streets, open drainage swales and an abundance of diverse
To slow down traffic and reduce impervious surfaces the roads and native plants. Gardens front the street integrating home and neighborhood,
were designed curvy and narrow, reducing impervious surfaces uniting the community visually, environmentally and socially.
by 11%.
A concept drawing of the $800,000 SEA project shows 14-foot-wide curved street,
swales, additional trees, vegetation and diagonal parking areas for cars.
Credit: DJC Seattle Journal of Commerce: Environment
for more information:
SEA Streets, curvy road http://www2.cityofseattle.net/util/tours/seastreet/
photo credit: City of Seattle; www2.cityofseattle.net
http://www.seattle.gov/util/About_SPU/Drainage_&_Sewer_System/
http://www.djc.com/news/co/11149502.html
RAINGARDEN

3. RESIDENTIAL RAINGARDENS
RAIN
GARDEN
Ashley Thorner
Raingardens
Urban + Residential
Tasmaninan Raingarden
photo credit: http://www.rtbg.tas.gov.au/
DIG IT! RESIDENTIAL RAINGARDENS
Raingardens are an easy and fun way to create beautiful landscape features that man-
age stormwater on site. They are planted depressions that are designed to take the
excess rainwater run-off from a house and its surrounding landscape. The plants used
are a selection of wetland edge vegetation, such as sedges, rushes, ferns, shrubs and
trees that absorb the excess water, and through the process of transpiration return water
vapor into the atmosphere.
Local Pacific Northwest Raingarden
Raingardens are beneficial for many reasons: they lessen the effects of drought, remove
pollutants from run-off, make paved areas more attractive, and provide interesting plant-
ing opportunities. They encourage wildlife and biodiversity, tie together buildings and
their surrounding environments in attractive and environmentally advantageous ways, as
well as making a significant contribution to environmental problems that affect us all.
Raingardens provide a way to use and optimize any rain that does fall, by reducing or
avoiding the need for irrigation. They allow a residence to deal with excessive rainwater
runoff without burdening the public storm water networks.
for more information:
A rain garden in Philadelphia, de- Raingarden- residential bog garden http://www.raingardens.org/Index.php; raingardens of West Michigan
signed by Edgar David. Rainwater photo/design credit: Mike Broili
that flows from the house roof to http://www.bbg.org/gar2/topics/design/2004sp_raingardens;
the stone cistern is used to irrigate Brooklyn Botanical Gardens
an intimate collection of woodland
plants http://dnr.wi.gov/org/water/wm/nps/rg/littleone/small.htm
RAINGARDEN

4. RESIDENTIAL RAINGARDENS
RAIN
GARDEN
Ashley Thorner
Raingardens
Urban + Residential
DIG IN!
PLANTING YOUR RAINGARDEN
RAInGARDEn PlAnT lIST
WESTERn MOUnTAInS AnD PACIFIC nORTHWEST
WiLdfLOWERS, fERNS, GRASSES, ANd SEdGES:
Raingarden vertical layers Aquilegia formosa, Columbine
http://www.ext.vt.edu/pubs/waterquality.html; Virginia tech
Aralia californica, Elk clover
Aruncus dioicus, Goatsbeard
CHOOSiNG PLANTS
Caltha leptosepala, Marsh marigold
Planting a raingarden is the fun part.
Camassia quamash, Camas
A variety of native wildflowers, ferns,
Cimicifuga laciniata, Bugbane
grasses, shrubs, and trees thrive in
Darmera peltata, Umbrella plant
moist soil. Your raingarden can be
Heracleum lanatum, Cow parsnip
divided into three wetness zones.
Mimulus guttatus, Monkeyflower
In the lowest zone, plant species
Adiantum pedatum, Maidenhair fern
that can tolerate short periods of
Athyrium filix-femina, Lady fern
standing water as well as fluctuating
Woodwardia fimbriata, Chain fern
water levels, because a raingarden
Carex obnupta, Sedge
will dry out during droughts or at
Carex testacea, Orange new Zealand Sedge
times of the year when precipitation
Juncus patens, Grooved rush
is sparse. Species that can toler-
Raingarden design Liriope muscari. Big blue lily turf
ate extremes of wet soils and dry Brooklyn Botanical Garden web page
periods are also appropriate for the
Trees and Shrubs:
middle zone, which is slightly drier.
Acer circinatum, Vine maple
You can put plants that prefer drier
Clethra alnifolia, Sweet pepperbush
conditions at the highest zone or
Cornus alternifolia, Pagoda dogwood
outer edge of your raingarden. Plant
Cornus sericea, Creek dogwood
as many species as you can to
Gaultheria shallon, Salal
enhance your raingarden’s value as
Ilex verticillata, Winterberry
wildlife habitat.
Raingarden vertical layers Physocarpus capitatus, Pacific ninebark
If your raingarden is shaded, plant http://www.ext.vt.edu/pubs/waterquality.html; Virginia tech Ribes sanguineum, Red-flowering currant
smaller understory trees and shrubs Rubus spectabilis, Salmonberry
such as river birch and sweet pep- Salix purpurea ‘Nana’, Dwarf blue willow
perbush, as well as ferns, sedges, Salix scouleri, Scouler’s willow
and wildflowers. Re-creating the
vertical layers found in a natural for more information:
forest will provide a number of dif-
http://www.raingardens.org/Index.php; raingardens of West Michigan
ferent habitat niches for a variety
of birds and other creatures. If you http://www.bbg.org/gar2/topics/design/2004sp_raingardens;
are planting in a sunny area, a wet Brooklyn Botanical Gardens
meadow full of colorful prairie wild- http://dnr.wi.gov/org/water/wm/nps/rg/littleone/small.htm
flowers and grasses is an appropri-
http://www.ext.vt.edu/pubs/waterquality.html; Virginia tech
ate choice.
RAINGARDEN

5. PUBLIC SChOOL RAINGARDENS:
RAIN
GARDEN
Ashley Thorner
Raingardens
Urban + Residential
GlEnCOE ElEMEnTARY SCHOOl
PORTLAND BUREAU OF ENVIRONMENTAL SERVICES:
DESIGnER: kEVIn PERRY
PORTlAnD, OR
2003
Raingarden
Glencoe Elementary school is part of the Oregon Green Schools program
photo credit: Portland Bureau of Environmental Services which promotes raising awareness, resource conservation and reduc-
ing the impact of schools on the environment in creative and educational
ways.
The Glencoe elementary school raingarden is multifunctional. It collects
runoff from adjacent streets, reduces storm water in the sewer system and
helps prevent local basement flooding and combined sewer overflows. It
mimics natural conditions by allowing storm water to filter through vegeta-
tion and soak into the ground as it moves slowly through the garden, infil-
trating into the base flow. The raingarden also serves to beautify the cam-
pus with native foliage and is used as an outdoor educational resource.
for more information:
www.portlandonline.com, Portland Bureau of Environmental Services
http://glencoe.pps.k12.or.us/schools/glencoe/staff/pletz/stormwater_
www.oregongreenschools.org
https://mttabor.pps.k12.or.us
RAINGARDEN