Portland, Oregon

Building a Nationally Recognized Program Through Innovation and Research

The City of Portland is a recognized leader in green stormwater management. The City is home to several award-wining BMP project designs, and its municipal program is highly regarded worldwide. Since the early 1990s, Portland's Bureau of Environmental Services (BES) has created a multi-faceted, highly successful program that achieves not only regulatory compliance, but also education, outreach, and community greening and beautification.

Stormwater Program Origins

Buckman Heights Apartments - Infiltration Basin (Source: Martina Keefe)
 

Portland's stormwater program began in the early 1990s in response to the National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Discharge Permit issued by the state to address water quality regulations. Portland began developing a stormwater management plan. . As part of the process of developing the plan, the team at BES examined the City's procedures and practices to identify activities the City already performed that met the new regulations. They also began implementing and monitoring new techniques to determine BMP feasibility and effectiveness. Armed with this information, they created a matrix of regulatory requirements and current practices to highlight where the practices met, exceeded, or failed to address the regulations. They then collaborated with other departments to identify new BMPs that were needed to meet the regulations, and in doing so established a "to-do" list and timeline.

The stormwater management plan that resulted outlines how stormwater will be addressed by the City and includes a specification that BMPs, including sustainable stormwater management systems, will be implemented to reduce pollutants in stormwater. To ensure that private property owners implemented the BMP requirements, the City needed to amend codes governing new and redevelopment. Because there were a number of possible approaches that could be adopted to require BMPs, in 1996 the City created a Stormwater Policy Advisory Committee (SPAC), which included a diverse group of stakeholders from landscape architecture, architecture, engineering, institutional organizations, and the stormwater treatment industry, to provide input to the City on stormwater matters.

Over the next three years, the SPAC developed policy and code statements, which were developed into the city's stormwater management manual; it describes City requirements for stormwater management and specific BMP design approaches. The manual is designed to ease calculations, streamlining formulas with simple coefficients, allowing users to plug in their numbers and get straightforward results. A chapter of the manual details simplified stormwater management BMPs designed to mimic natural systems using plants and soil. The manual is updated every two years based on stakeholder input and knowledge obtained from monitoring demonstration projects.

Early on, Portland developed the Combined Sewer Overflow (CSO) Facilities Plan under the CSO Abatement Program. They looked at BMPs for flow control to address CSO events in the Columbia Slough and Willamette River. In the Plan, downspout disconnection was recognized as one of four Cornerstone Projects, which are relatively low-cost projects that reduce CSOs by keeping stormwater runoff out of the combined sewer system. (Other Cornerstone Projects were sewer separation, sump installation, and stream diversion.) As a direct result of the Plan, Portland created the Downspout Disconnection Program in 1993, in which the City provides outreach and incentives for residents of selected neighborhoods to disconnect downspouts from the combined sewer system and to redirect roof water to gardens and lawns. More than 50,000 homeowners have disconnected downspouts, removing nearly one billion gallons of stormwater per year from the combined sewer system.

Since 1977 Portland has charged a separate stormwater utility fee to help pay for stormwater management costs. In 2000 the City Council established a reward system for ratepayers who keep stormwater from leaving their property. This program, called Clean River Rewards, came into effect in October 2006 after the City launched a new utility billing system. Clean River Rewards offers residential ratepayers up to a 30 percent discount based on the extent to which they can manage runoff from roof areas. Commercial customers can claim a discount for managing runoff from both roof and paved areas. Credits are offered for having a small impervious footprint (less than 1,000 square feet), creating or maintaining tree coverage, disconnecting downspouts, installing rain gardens or drywells, and other low impact development BMPs. The City processes applications without site visits and conducts oversight via spot checks to ensure that BMPs are in effect and maintained properly. To assist ratepayers with stormwater retrofit options, BES hosts an online technical assistance page and offers workshops tailored to residential and commercial customers.

Sustainable Stormwater Management Program

Swales Collect Parking Lot Runoff - New Seasons Market (Source: Martina Keefe)
 

The City recognized a need for both internal coordination and promotion of sustainable stormwater management systems Citywide. In 2001 the Sustainable Infrastructure Committee was formed to coordinate efforts by City staff to investigate such options as porous pavement, enhanced street landscape, and stormwater reuse to limit the impacts of City projects on water quality. Shortly thereafter the Sustainable Stormwater Management Program was formed within BES. The group's functions are many. They monitor and test the performance and design of pilot stormwater BMPs, and they provide technical assistance to developers and designers who are incorporating stormwater measures into site designs. They partner with property owners (commercial, industrial, and institutional), other local public agencies, and the federal government with project design, funding and implementation. They develop supporting policy and implement specific program areas, including Green Streets, ecoroofs, and monitoring. The group also provides project documentation, outreach, and public education. Staff receive many calls from outside Portland as other communities strive to match Portland's success with stormwater BMPs.

Program Highlights and Successes

Portland's stormwater management program has seen success after success as new programs are developed and as BMP projects are implemented throughout the City. Below are a few examples of Portland's multi-faceted and highly successful initiatives.

Green Streets:
Portland has retrofitted a number of streets with landscaped curb extensions, swales, planter strips, pervious pavement, and street trees to intercept and infiltrate stormwater. These Green Street projects demonstrate ways to address street runoff, which is an important source of stormwater as streets comprise 35 percent of the City's impervious surface. In April 2007, the City Council approved a resolution, report, and policy to officially promote and incorporate the use of Green Street facilities in both public and private development. Green Streets are recognized as an important in-flow control strategy to address combined sewer overflows, sewer backups, and other system deficiencies as well as watershed health needs.

SW 12th Ave Green Street Planters (Source: Martina Keefe)
 
 
 

A number of green street projects have been installed throughout Portland, and more are being planned as retrofits for existing neighborhoods. One project, the SW 12th Ave Green Street Planters on the Portland State University campus, won an American Society of Landscape Architects Design Award in 2006. This project, built in 2005, includes four stormwater planters arranged in sequence that capture and treat runoff from 8,000 square feet of street surface. Water flows along the curb and enters the first planter via a channel cut into the curb. Depending on flows, water will pond to a depth of 6 inches, promoting infiltration and biological uptake of pollutants. If flows exceed this capacity, water will exit the first planter through a second curb cut and be routed into the subsequent planters, either infiltrating to groundwater or, during intense storms, eventually entering the storm drain system. The planters themselves are designed to be long and narrow to fit into the existing sidewalk space, and they contain a mix of rushes, trees, and shrubs that provide attractive landscaping year-round. To address access and safety concerns in the pedestrian right-of-way, the designers used metal grates to cover the curb cut channels, incorporated exposed curbs to warn pedestrians of the difference in grade, and set the planters back from the edge of the street by three feet to allow passengers to exit their cars.

Ecoroof - Native American Center (Source: Martina Keefe)
 

Ecoroofs:
A number of buildings and structures in Portland have living, vegetated roof systems that decrease runoff and offer aesthetic, air quality, habitat, and energy benefits. The City offers developers proposing buildings in Portland's Central City Plan District the possibility for floor area bonuses if an ecoroof is installed, allowing for additional building space than would otherwise be allowed. The City is considering expanding this bonus Citywide. Additionally, Portland adopted a policy that directs City bureaus to incorporate green building practices into all facilities constructed, owned, or managed by the City. The policy specifically requires ecoroof design and construction on all new City-owned facilities and all roof replacement projects.

Sustainable Stormwater BMP Monitoring:
The Sustainable Stormwater Management Program monitors and reports the results of a variety of BMP demonstration projects throughout the City. They use these data to quantify benefits of sustainable stormwater practices, improve the design and function of BMPs for existing and future applications, and lower maintenance costs by tracking performance and addressing maintenance needs as they arise. The Sustainable Stormwater Management Program produces regular reports of monitoring efforts, including project-specific results, on their website.

Mt. Tabor Middle School Rain Garden (Photo Credit: Mt. Tabor Middle School)
 

BMPs at Schools
In addition to a wealth of BMP projects implemented at new development, redevelopment, and capital improvement projects throughout the City, Portland schools has partnered with the City to install facilities that can manage up to 90 percent of the stormwater on site. Schoolyards have been turned into educational facilities to inform students about watershed health, and the practices have helped to prevent sewer back-ups in neighboring houses by providing a safe outlet for stormwater. One such project, at Mt. Tabor Middle School in Southeast Portland, won a 2006 Design Award from the American Society of Landscape Architects. Neighboring residents had experienced sewer back-ups during heavy rains as a result of excess stormwater, so a rain garden, landscaped curb extension, and sump were installed on and surrounding the school grounds. The rain garden drains three-quarters of an acre of roof area and asphalt, and it contains a variety of shrubs, grasses, and trees to slow runoff and promote infiltration. The design was intended to appear open while at the same time providing shade. A fence and shrubs were used to limit access to the feature, and the garden was designed to drain within a day with a maximum ponding depth of 6 inches. The design incorporated a variety of playful elements that allow passersby to watch the water flow through the system during rainstorms.

Funding Mechanisms
The Sustainable Stormwater Management Program provides funding for stormwater management projects through various grant and matching grant programs. Federal grants are used for Innovative Wet Weather Projects, the BES Watershed Services Division administers Community Watershed Stewardship Program grants for community-proposed projects as well as Watershed Investment Funds, and the Office of Sustainable Development offers Green Investment Funds, all of which can be used to implement sustainable stormwater management practices.

City Programs Supportive of Sustainable Stormwater Management

NE Siskyou Green Street - Landscaped Curb Extension (Source: Martina Keefe)
 

Other City programs and initiatives that promote natural system approaches to stormwater management supported the efforts of the Sustainable Stormwater Management Program, particularly with respect to watershed planning efforts. For example, in 2004 Portland proposed the Clean and Healthy River Strategy as a comprehensive effort under the River Renaissance Strategy to clean up the Willamette River. The strategy includes creating healthier tributaries and watersheds, improving habitat for endangered fish, and creating a livable, sustainable community. Reducing CSOs is a key part of the strategy. The Clean and Healthy River Strategy also includes expanding Portland's program to disconnect residential downspouts from the combined sewer system; encouraging commercial landowners to install swales and other facilities to store and filter stormwater runoff; planting more street and landscape trees to absorb rainfall, filter stormwater runoff, and shade streams; and offering incentives to homeowners to reduce stormwater runoff from private property.

Portland considered larger, watershed-scale issues through its 2005 Watershed Plan. The basis for the plan is the Portland Watershed Management Plan (PWMP), which integrates the activities of many City bureaus. The PWMP maximizes the use of limited resources by looking for solutions that meet multiple objectives, and it focuses on addressing environmental problems at their source. This comprehensive approach to watershed management also coordinates compliance with multiple environmental regulations, including MS4 permit requirements; the stormwater management plan is recognized as one part of the overall effort to improve watershed health.

The Secrets of Their Success

Part of the Sustainable Stormwater Management Program's success is the fact that it is integrated with other stormwater-related programs within BES. Each staff member in the Program is also involved in other initiatives or regulatory programs, such as sewer backups, combined sewer overflow control, the NPDES municipal stormwater permit, and others. Also, each activity is tied to Portland's larger watershed objectives. Finally, the Program is made up of a mix of engineers, environmental specialists, and landscape architects who offer unique approaches and perspectives to stormwater management challenges.

SSMP staff credit some of the Program's successful innovations to a provision BES included in their original NPDES permit application that required the City to conduct research on better ways to manage stormwater. As a result, in the early 1990s the City began implementing and monitoring BMPs, referred to as Early Action Projects, to determine their feasibility and effectiveness. These projects were implemented mainly on publicly held properties, and they have formed the basis of Portland's experience with green technologies. Based in part on their success, the City has expanded its application of green technologies in its capital improvement projects and in its requirements for new development. The Sustainable Stormwater Management Program continues to act as a "research and development" arm of BES, testing out new designs in a variety of settings, and they pass on their experience on to others who design Portland's capital improvement projects.

Lessons for Other Communities

Stormwater Planter - Butler Promotions (Source: Martina Keefe)
 

Outreach to other jurisdictions is helpful early in the process to find out what other communities are doing to manage stormwater and what lessons they have already learned, particularly overseas. Now the Internet and conferences offer opportunities to interact and share with other communities and professionals at large. That said, Portland emphasizes the importance of using what can be learned from other communities to develop a unique strategy that is tailored to meet the particular needs of the community.

One of the lessons Portland staff want to emphasize is that the right-of-way is already within a city's authority, making projects like Green Streets fairly easy to do. Stormwater managers and planners still want to consult with homeowners about their aesthetic preferences and expectations to ensure community acceptance. The City has received a wealth of positive feedback about the green street installations because of their beauty-they are valued by residents as an amenity, and this is one of the most important and rewarding reasons to use green approaches wherever possible.

They also want to stress that a successful sustainable stormwater program requires a multi-disciplinary approach that involves landscape architects, engineers, planners, reviewers, department heads, and watershed managers. They knew they needed the participation of all these groups in discussions and planning for individual projects as well as Citywide initiatives. This type of collaboration can also bring more resources to the table where funding for a project or initiative might be limited.

Members of the community should be credited for recognizing the value of sustainable stormwater management and for serving as advocates for projects and initiatives. For example, a number of citizens have requested that the City install Green Streets in front of their homes or businesses and have asked how they can get more involved.

Portland has seen the value in starting small with demonstration projects. Implementing a few pilot projects allowed them to monitor the practices and modify the designs for improved function and effectiveness before being implemented more widely. Because of the supporting monitoring data, Green Streets and other BMPs are recognized as one solution to the City's CSO issues. In fact, up to 500 Green Streets are being included in the pre-design of a large drainage basin to alleviate CSO and sewer back-up challenges.

Finally, sustainable stormwater approaches are seen as an important watershed health strategy. As the Portland area continues to develop and urbanize, Green Streets, ecoroofs, rain gardens, and simple impervious area disconnection help to transform the landscape and achieve multiple objectives, from stormwater flow and water quality management to cooling the air, providing habitat, enhancing neighborhoods, and improving property values.


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