Major project over seven blocks should cut pollutants into Oswego Lake
by: Sam Bennett, 
On 10th Street, the city of Lake Oswego is building a pilot project involving stormwater bioswales.

When the rains come this fall, Lake Oswego's 10th Street will be ready.

A seven-block stretch of 10th Street in First Addition and Evergreen neighborhoods is being transformed into an eco-friendly pilot project that the city officials hope will reduce the pollutants going into Oswego Lake.

Designed by Lango Hansen Landscape Architects, a Portland firm, the green street will have rain gardens and vegetated swales that will remove sediments from stormwater runoff.

'It's the city's first foray into green streets development,' said Joel Komarek, city engineer.

The city began planning the $1.58 million project about two years ago.

The city found 10th Street to be the ideal setting - a continuous stretch of street that is one of the few areas in the city with an expansive public right of way, according to Komarek.

The right of way is 60 feet wide at its most narrow point, and 100 feet wide at its widest.

'The encroachments were primarily people's lawns and individual parking spots,' Komarek said. 'The cost and political acceptability of reclaiming the right of way was seen as feasible.'

The project will have 20 bioswales, which are like large stormwater planters or shallow bathtubs that have special soils and plants that filter stormwater. The water then drains through the bottom of the swale into stormwater pipes.

The idea is to filter sediments and pollutants from the roadway, so it cannot end up in Oswego Lake and nearby lawns. Some of the water can be used for irrigation.

The city will use an Australian company's system called KISSS, which stands for Kapillary Irrigation Sub-surface Systems. Another irrigation system the city will use is made by MP Rotators from Walla Walla, Wash.

At the north end of the project, on E Avenue and 10th Street, there will be will stormwater cascades, an architectural feature with randomly placed boulders that help create a gradual waterfall and pools. As the water moves down the gentle grade, it will be filtered of suspended solids and pollutants such as phosphorous.

'When it gets to a stream or the lake, it will be cleaner,' said Komarek.

The street will be accented with native plantings. In addition a sidewalk will be added, providing safer passage on 10th Street for students heading to Forest Hills Elementary School. New paving will allow for parking in front of homes.

'The city worked with each home-owner to address unique property circumstances,' according to Lisa Shaw-Ryan, chair of the First Addition Neighborhood Association. 'We hope some of the green concepts can be used in other neighborhood streets as well.'

Komarek said the city would be hard-pressed to find another stretch that would accommodate a project of this scope.

But, he said, 'We look to use these features on a much smaller scale' in other parts of the city.

The city has a smaller bioswale project also under construction on West Bay Road and Virginia Way. The $966,000 project will have 13 filtering planters.

The project has not been popular with Mary Goranson, who lives on West Bay Road. Goranson said the planters will mean losing parking spots in front of her house. Neighbors have told Goranson the project is not a welcome addition.

The planters, she said, mean Goranson will 'have to change my entire landscape to make my place look good again.'

'We've been sitting in dust and grit and noise and we don't even know if this project is going to work,' she said. 'We're guinea pigs.' She called the bioswales a 'Band-Aid' fix for cleaning stormwater.

While the water filtering may not have a major impact on Oswego Lake's overall water quality, Komarek said the runoff will be much cleaner than before.

'I expect we will see what I would describe as pretty dramatic improvements in terms of quality of water that gets to the lake or any other receiving stream,' he said. 'A key component will be the ongoing maintenance and monitoring, and how these systems are performing as far as removing sediment.'

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