For the last 18 years the city of Portland has been on a mission to improve the area’s watershed health. The city will spend $1.4 billion by the end of 2011 to manage stormwater. The city built larger pipes and is investing in green streets. There are 750 green streets or rainwater gardens, as they’re sometimes called, in Portland. The city’s goal is 900.

Green streets are vegetated facilities that filter and manage stormwater runoff. To the average person they may look like a planter box, but they actually provide a real and important function. When it rains, water from the street flows into the facilities through an opening. The plants, soil and rocks slow the water down and clean it naturally. The green streets help maintain capacity in the system by capturing water and keeping some of it from getting into the pipes.

The City’s Sustainable Stormwater Division Manager, Linda Dobson, says green streets provide a number of other benefits including cleaning the air, and making sidewalks safer for pedestrians by slowing down traffic and providing a buffer.

The installation of green streets is part of the city’s Gray to Green Initiative, which is a five-year plan to invest in green infrastructure.

Dobson says the city is doing all this work in order to make sure the Willamette River is clean and healthy for everyone.