By Tawnee Milko, MEM ’12, Photography by Steve DiPaola
Portland Oregon is a metropolis enmeshed in water. Bordered on the north by the great Columbia River and bisected by the Willamette River, the city provides water-related utilities to more than 600,000 residents—and protects watersheds through which 13 species of threatened or endangered salmonids migrate annually. Add in the Pacific Northwest’s trademark wet winter climate, and proper stormwater management, usually an invisible city service, could not be more critical.
“Stormwater—it’s rain,” says Jane Bacchieri MEM’94, manager of the Watershed Services Group within Portland’s Bureau of Environmental Services. “When it lands, it has to go somewhere. But unless it’s a problem at their house, many people don’t understand the impact stormwater can have on our natural systems, and the broader impacts on human health.”
Thanks to the pioneering efforts of such dedicated personnel as Bacchieri, Naomi Tsurumi MEM’02 and Henry Stevens MEM’92, the City of Portland has become a worldwide leader in sustainable stormwater management. It is a journey that has been long, challenging, and expensive, but also one that has resulted in the development of new, and green, best management practices that today are being employed by municipal governments nationwide.
When a drop of water falls to earth, it typically faces one of three fates: seeping directly through soil into the ground, merging with an open body of water, or collecting on an impervious surface like a roof, road or parking lot. In dense urban areas, where up to 100 percent of surfaces can be impervious, stormwater management systems, usually in the form of pipes, help direct rainfall to sewage treatment plants or to natural waterbodies like streams and rivers.
While metropolitan areas have continued to expand, however, aging pipe infrastructure often has not. During heavy rainfall, stormwater can overload undersized or failing pipes, resulting in significant problems like basement sewer backups, urban flooding, sewage system overflows, pollutant transfer into greenways and waterways, and severe stress on local river ecosystems.
Portland, which contains a 150-year-old combined sewer and stormwater system—in which the same pipe network carries both sewage waste and stormwater—was no exception.
“Until 20 years ago, we had sewage overflowing into the Willamette River almost every time it rained,” says Tsurumi, an environmental specialist in Bacchieri’s Watershed Services Group.
Combined sewer system overflows (CSOs) are subject to Clean Water Act regulations and the permit requirements of the EPA’s National Pollutant Discharge Elimination System (NPDES). It took a major lawsuit citing both to spur Portland to begin a $1.4 billion combined sewer system overhaul in 1991. Completed in 2011, the CSO Control Program was the largest public works project in the state’s history. At federal agencies’ insistence, the program primarily included “grey” technologies, i.e. newer, more, and bigger pipe-andpump systems, which, Bacchieri explains, the EPA at the time viewed as the most effective solution for combined sewer system overflows.
That didn’t stop the Portland bureau’s staff from including a provision in their earliest NPDES municipal stormwater permit application that required the city to conduct research on more effective ways to manage stormwater. As a result, watershed managers began experimenting with green stormwater management techniques across the city, including engineered landscape systems like rain gardens, bioswales and green street planters (small rain gardens that line roads and parking lots to collect stormwater).
“All these facilities are variations on the same theme,” says Stevens, who focused on water resources and soils during his time at the Nicholas School and has managed stormwater projects for the City of Portland for more than two decades since. “The goal is to create landscape areas where we can divert stormwater that will absorb it directly.”
Portland also has employed strategies like planting trees, acquiring natural areas and disconnecting building downspouts to redirect roof runoff toward more permeable landscapes, such as lawns and gardens. The latter, called the Downspout Disconnection Program, is a seemingly simple but high-impact undertaking involving tens of thousands of Portland households that removes almost a billion gallons of stormwater from sewers per year.
“The CSO Control Program really pushed us forward to test new green systems,” Stevens says. “We had the financial backing and the sense that we had to figure out a way to do this.”
It became evident, he explains, that keeping extra water out of the combined sewer system, which green facilities are good at, was the most cost-effective way to reduce the size and price of new “grey” underground pipe infrastructure.
Green facilities also provide a host of ecosystem services. Among others, filtering stormwater through soil before it flows into watersheds removes most silt and pollutants, improving local water quality, especially for sensitive salmonid species. By reducing stormwater flows, they also protect combined sewers and creeks from damaging water surges, which in turn helps restore some natural hydrologic function to urban water systems.
Still, the grasses, shrubs, trees, channels and ponds that characterize many green systems come with their own cost—regular long-term maintenance— which pipes don’t require.
“We call these natural systems, and in certain ways they are. But if you can imagine a green planter in a street, it’s a super urban setting as far as the heat and the dryness that the systems can be exposed to during summers. They’re not in a natural setting,” Stevens says. “Sometimes it costs less to upsize the local sewer line than it does to find the land and design, construct and maintain green stormwater systems over a period of, say, 50 or 100 years.”
Stevens’ colleague, Tsurumi, has been applying tools she first learned in Professor of the Practice Lynn Maguire’s “Environmental Decision Analysis” class to more adequately capture the full costs and benefits of proposed sustainable facilities. At an asset management planning level, it can be difficult to evaluate project alternatives that contain both grey and green infrastructure solutions.
For example, Tsurumi says, it’s far easier to measure the money the city saves by not sending X gallons of water to treatment plants through pipes, because of associated energy costs, than it is to quantify the myriad ecosystem services—such as water quality, aesthetics, and wildlife habitat—that green systems offer.
In 2008, she piloted the use of multiattribute utility analysis in the planning process for combined sewer updates to a large drainage basin between Mt. Tabor Park in SE Portland and the Willamette River, a project aptly named “Tabor to the River.” This type of analysis, compared to the purely quantitative evaluation of the cost and volume of piped water, can assign values to project attributes like ecosystem services, so they can be factored into a numeric scoring of decision options.
“The multi-attribute utility analysis allowed us, for the first time, to place our watershed objectives and our pipe objectives on the same table and rank them based on which ones were most important,” says Tsurumi, who has since applied multi-attribute utility analysis to a number of other municipal projects.
“Then we could quantify how far each potential project got us toward meeting these joint objectives.”
Ultimately, the Tabor to the River planning team decided upon a design which, in addition to repairing or replacing 81,000 linear feet of sewer pipe, included the installation of 500 green streets, 100 private property rain gardens, 3,500 street trees, and natural area restoration to help divert stormwater from the sewer system. Together, the green and grey measures saved the city $63 million in construction costs when compared to an all-grey alternative, with added environmental benefits.
Realizing that such substantial construction would require more than the usual outreach to neighborhood residents, Bacchieri’s Watershed Services Group rolled out a unique educational component to help citizens understand how the highly visible green infrastructure would fit into the bigger picture of what the Portland bureau was doing to keep watersheds clean and stop wastewater from backing up into homes. The initiative included ads in local newspapers, a website, newsletters, responsible stormwater management workshops for property owners, and an “Art of Stormwater” exhibit circulated around Mt. Tabor area coffee shops.
Community engagement is a small but integral piece of the Portland bureau’s operations, says Bacchieri. From Community Watershed Stewardship grants to a reward system that offers discounts to ratepayers who keep stormwater from leaving their property, the city offers funding and incentive programs to encourage citizen stormwater management, and has built partnerships with nonprofits, business owners and local schools.
Bacchieri, formerly natural resources policy advisor to the Oregon Governor’s Office and collaborative systems program manager at Portland State University’s National Policy Consensus Center, is no stranger to partnership building. Before she rose to prominence in Oregon’s water resource management scene, she received a Bradley Fellowship to study marine policy at the Duke Marine Laboratory, where she was able to gain real-world experience working on such public sector multi-disciplinary programs as the Albemarle-Pamlico National Estuary Partnership.
Under her leadership, the Watershed Services Group has implemented standardized monitoring of local waterways and developed a watershed health index. On Earth Day 2015, the Portland bureau released the first Portland Watershed Report Cards, scoring such characteristics as hydrology, water quality, fish and wildlife, and habitat. Many indicators, like effective impervious area, total suspended solids, and the levels of specific pollutants, are related to stormwater management.
“People in Portland care deeply about the environment and about the river, and they try to stay very well informed,” says Bacchieri. “Beyond measuring our own progress in improving watershed conditions, the Report Cards are another way we can keep the community engaged and together look for opportunities to reduce the effective impervious area in the city, such as by de-paving, reducing surface parking lots, or adding green landscaping.”
City residents also have served as advocates to help push sustainable stormwater projects through a generally supportive City Council. Last November, the Tryon-Stephens Headwaters Neighborhood Street Plan was approved with significant community support, thanks in part to Tsurumi and her colleagues’ painstaking efforts during the project’s planning process to obtain the input of scores of residents in the southwest Portland neighborhood.
The groundbreaking Tryon-Stephens Plan marks the first time that Portland’s Bureaus of Environmental Services and Transportation have collaborated on a neighborhood scale, bringing a wider breadth of resources to the table. Given funding limitations that plague even the most enterprising environmental bureaus, the team-up between the two bureaus just made sense, Bacchieri says, since both departments work in the public right-of-way.
“It’s not just one bureau that can do this work,” she says. “To address multiple regulations in a more integrated manner across watersheds, we need to coordinate with other bureaus in the city and with the community. It can be time-consuming, and there can be some bumps along the road, but it’s really exciting when you complete these projects and look at all the people involved and think, Wow, we did this together.”
Indeed, Bacchieri, Stevens and Tsurumi exude enthusiasm when describing their regular collaboration with the ecologists, botanists, hydrologists, economists, engineers, planners, and landscape architects also on City of Portland staff. They credit the Nicholas School’s interdisciplinary master’s degree with providing the background to help them work more easily with experts across disciplines to solve the practical problems surrounding water-related environmental issues.
But they remain mindful of the decades of hard work that has led to Portland’s success—especially when utility managers from around the globe ask them about the adaptability of Portland’s green infrastructure to other major cities, many of which are only just beginning to tackle the sewer and stormwater management challenges that Portland took on a quarter century ago.
“It’s taken us years to get here. And we’re still learning,” Stevens is quick to point out. “Figuring out the local nuances of these systems, taking stormwater management ideas all the way through design and permitting, and building enough trust between bureaus to collaborate on projects can take a long time.”
Bacchieri looks forward to the day when green infrastructure isn’t viewed as a novelty by the public and by many municipal colleagues, but instead is better understood as simply the way the city does business. “I think sometimes it’s still seen as either the add-on or the exception, rather than just another tool in the toolbox,” she explains.
The future of urban stormwater management, agree the three Nicholas alumni, relies not on a blanket prescription for the addition of specific sustainable technology, but on everexpanding cities becoming open to the idea of experimenting with nature-based systems that fit their own watershed needs, infrastructure, funding and culture.
“At least in terms of stormwater, we’re past the point where we can manage everything in a pipe,” Tsurumi says. “The pipes can only be so big; we only have so much money to go back and put in bigger pipes all the time. We have to come up with more creative solutions, and we have to rely more on partnerships to keep the rivers clean.”
Tawnee Milko MEM’12 has been a Nicholas School student and staff member and led the Dukenvironment blogging team. She is now writing and living in Michigan.