Foreword

This letter was written at the time of the Urban Street Stormwater Guide’s publication (2017).

Water is a resource, not a problem.

For too long, cities have treated water as waste. Stormwater has been viewed as something to be managed,” and streets have prevented stormwater from doing exactly what we most need it to do: get back into the ground. But just like building new highways doesn’t solve traffic congestion, adding capacity to traditional ‘gray’ stormwater systems is proving to be financially, and ecologically, untenable. And with a changing climate bringing more frequent and intense storms, heat waves, and droughts, pressure is mounting to protect against flooding risks, improve water quality, and build resilient urban places.

The urgency of this challenge requires us to make better use of our resources. Both transportation mobility and stormwater management are rooted in physical street space. A siloed approach results in competing priorities and conflicting project timelines. The streets and sidewalks that disrupt natural hydrology with an impermeable surface of asphalt and concrete must be reimagined as sites for sustainable stormwater infrastructure. Instead of competing for street space, our transportation and water management agencies must work together to find value in stormwater and integrate ecology into urban life.

Here in Seattle, we understand that complete streets that incorporate natural drainage solutions make our city a better, more resilient place. Investments in green stormwater infrastructure that support a healthy water cycle are paired with geometric changes in the right-of-way that calm traffic and make room for walking, biking, and public space. A partnership between the Seattle Department of Transportation (SDOT) and Seattle Public Utilities (SPU) allows us to capitalize more fully on opportunities in the public right-of way. Green Streets are codified in the Land Use Code and require private developments to incorporate green stormwater infrastructure into their design. Complete Streets, mandated by ordinance in 2007, requires SDOT to assess each capital project’s opportunity to incorporate green stormwater infrastructure. These two regulatory tools result in projects that create functional green spaces that contribute to a more vibrant streetscape.

We’re not alone in putting stormwater to better use. Cities around the country are institutionalizing partnerships, creating holistic programs, and adopting best practices in stormwater street design. From Philadelphia’s Green City Clean Waters program, to Denver’s Ultra-Urban Green Infrastructure Guidelines, to Portland’s Grey to Green initiative, we’re seeing intentional approaches to sustainable stormwater management centered on the role of streets.

The Urban Street Stormwater Guide synthesizes this wealth of local experience into a national resource for sustainable design. The result of a nationwide collaboration between city transportation and stormwater experts, the guide illustrates how streets of every size can incorporate stormwater management techniques alongside sustainable, multi-modal mobility.

From bioretention swales in transit boarding islands, to stormwater curb extensions that shorten crossing distances for pedestrians, to protected bike lanes built with permeable pavement, we can, and must, put our public assets to work, holding our infrastructure to a higher standard. The Urban Street Stormwater Guide provides the tools we need to do so. Together, we can find value in water and design better cities.