Adopt-a-Downspout creates cleaner waterways for healthier salmon. In order to properly drain rainwater and create safe driving conditions, bridges have vertical pipes that function like downspouts from a house’s roof gutters. The Adopt-a-Downspout (AAD) program installs aboveground stormwater biofiltration planter boxes at the bottom of the downspout.
Each box, also referred to as a Box of Rain, filters pollutants from the runoff before it flows into storm sewers or the water below, functioning much like a natural forest to filter rainwater. This filtering process significantly removes pollutants including 6PPDQ from the runoff resulting in cleaner waterways for all.
One Box of Rain or biofiltration box can treat up to 250,000 gallons of polluted stormwater annually. 250,000 gallons of water = ~4,000 bathtubs full annually
Elevated bridges and roadways transport pollutants as cars pass over the bridge. Take our pilot site at the I-5 Ship Canal Bridge for example with nearly 200,000 cars daily. Rainfall and snow melt carry polluted water into the Ship Canal. 6PPDQ, a pollutant from tires, was recently identified as a cause of Urban Runoff Mortality Syndrome. Tires from vehicles contain the additive 6PPD. As 6PPD interacts with oxygen, ozone, and temperature fluctuations, it transforms into 6PPDQ. In many cases when adult coho salmon are exposed to these lethal chemicals, they die before they are able to return to urban streams and rivers to lay their eggs. The Box of Rain technology on average filters out 92% of 6PPDQ to protect aquatic ecosystems.
We’re on a mission to install Boxes of Rain throughout the Pacific Northwest, engaging local communities in the adoption and maintenance of each box. Join us!
Get Involved
We work with government agencies, environmental groups, global companies, and local communities to maintain and scale the Adopt-a-Downspout program. This effort requires the support of funders and downspout adoptees who volunteer their time and energy to keep the Boxes of Rain in working order, especially after heavy rains.
Stewardship Partners’ Box of Rain is a nonproprietary technology. As we seek to expand with more sites and reduce toxic chemicals from harming salmon, we are pursuing a TAPE certification, an approved best management practice by the Department of Ecology, to establish the Box of Rain as a BMP.
We have created the following Box of Rain guides to train others and replicate more sites: Design Guide, Installation Guide, Operations & Maintenance Guide. If you intend to construct Boxes of Rain, please consult our staff for guidance. There are many rules and regulations that vary among Departments of Transportation, and Stewardship Partners can provide support navigating those.
Northwest Fly Anglers maintaining their adopted downspout site under the I-5 Ship Canal Bridge in Seattle.
For more information about Adopt-a-Downspout, becoming a funder or adopter, please contact David Burger at db@stewardshippartners.org or (206) 292-9875.
Thank you to our Adopt-a-Downspout Partners, Funders, and Adoptees!
This project has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement PC-01J95801-2 to the Washington State Department of Ecology. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.
Box of Rain filters polluted stormwater from elevated bridges and roadways before it flows into storm sewers or the water below.