Portland – It Comes Back to Water

Ecoroof in Portland

Ecoroof in Portland. Credit: Sam Churchill

Portland just completed one of its biggest infrastructure projects in the city’s history: a $1.4 billion main pipe, the Big Pipe, that delivers sewage and stormwater to the city’s treatment plant. BES’ Rosen relates that to keep this pipe below capacity, the city must keep stormwater off the system. “The credo is that it’s a lot cheaper to protect infrastructure than it is to restore it,” he says.

“People understand pipes,” adds Karps. “One of the things that we do is a lot of outreach and education to try to bring people up to speed about the importance of planting a tree. Planting trees is tantamount to pipe work, but is less expensive and you get all of the complementary benefits urban trees provide.”

Hence, Grey to Green’s emphasis on planting trees. Approximately 83,000 trees will be planted under Grey to Green to help remove stormwater from the grid. BES isn’t limiting its efforts, though, to public trees, as they’re trying to get private citizens to help mitigate stormwater effects through a program called Treebate.

Treebate is an incentive program for private landowners to plant trees. The concept is simple: Homeowners plant any tree they want from an approved list of eligible tree species. Then, they submit the receipt to BES. As a result, the homeowner receives a credit on his utility bill for half the purchase price of the tree up to $50. For a city with some of the highest stormwater rates in the country, this is no small incentive.

Grey to Green, though, isn’t the only BES program looking to reduce stormwater in the city. In 2008, BES began work on Tabor to the River, described by BES’ Naomi Tsurumi as “our most advanced integration of sewer and watershed as one in both predesign and implementation.” While the Big Pipe was designed to improve overflow problems for the city at large, localized pipe problems that could result in things like flooding basements are still an issue, which is what Tabor to the River is designed to address.

Focusing on 1,400 acres of the city from Mt. Tabor Park to the Willamette River, the 10-year Tabor to the River project will plant nearly 3,600 trees, create 500 green street facilities (such as streetside planters that collect stormwater runoff), remove invasive vegetation, repair or replace 81,000 feet of sewer pipe and work with property owners to collect and manage roof and parking lot stormwater runoff.[1] The project’s designers determined the number of trees needed for the project, Tsurumi relates, by calculating the number of available spaces for trees and then comparing those locations with pipes with hydraulic problems — such as pipes that were too small to handle the flow of water during peak times. It’s estimated that by using a combination of gray and green infrastructure to solve the sewage and stormwater issues in this area of the city, Portland will save almost $63 million compared to the cost of pipe-only solutions. According to Tsurumi, a hallmark of Tabor to the River is that it was the first time that BES incorporated both engineering and watershed goals, objectives and tools from the beginning of a project.

This type of joint work is imperative to continued success, expresses Karps. “The strength of our program certainly is our partnerships. Not just our public-private partnerships, but also our public-public partnerships. When we reach across our bureau boundaries and work together, it’s not always easy to do, but those projects that span bureau boundaries are the most satisfying. That’s when we really achieve something that’s meaningful and lasting.”

Adds BES Watershed Manager Rosen, “We’re interested in planning well, and we value green resources. We don’t have all the answers, but we see these resources as part of the solution. We’re very good about aspiring to integrate green infrastructure with traditional gray infrastructure.”

Previous: Portland – Partnering for Trees                            Next: Focus Story – Improving the Portland Metro Area



[1] Portland Bureau of Environmental Services. Tabor to the River 2009. http://www.portlandonline.com/bes/index.cfm?c=50500&a=230066 (accessed Sept. 4, 2012).