Environmental Services will replace and repair 4,508 feet of aging sewer pipe, construct 22 green street facilities and plant trees to absorb rain and reduce stormwater runoff. The project will keep about 1.6 million gallons of stormwater out of sewers annually, increase sewer system capacity and reduce the risk of basement backups. This project is part of the Tabor to the River Program, which combines green infrastructure with pipe repair to save Portland sewer ratepayers more than $60 million dollars.
The project design team has completed about three quarters of the design process, and will soon have a final plan. Input from neighborhood residents has helped the team develop the project design.
Additional studies of the area resulted in significant design changes (see map below). The original plan was to construct about 30 green street planters along SE 8th and 10th avenues that would allow stormwater to soak into the ground. But a soil analysis showed that ground conditions in some areas aren't suitable for stormwater infiltration.
This map is not to scale and is meant to show the proposed work at the general location.
The project team eliminated green street planters from the design and instead will construct larger diameter sewer pipes and additional pipes along SE 9th Avenue between Clinton and Woodward and along SE 10th Avenue between Franklin and Rhone. The project still includes constructing green street planters along SE 10th Avenue from the park to SE Rhine. There are no changes to the project plan for the area east of Milwaukie Avenue.
These kinds of changes are not uncommon when designing sewer construction projects. The project team will now complete design and invite construction bids from contractors. Construction should begin in winter 2014. Watch for more information as construction gets closer.
Project at a Glance
- 22 green street facilities
- 1.6 Million gallons of stormwater removed from system
- 11 street trees planted
- 4,508 feet of pipe work
- Construction begins this winter
To receive the most timely updates, which are especially useful during construction, please add your name to the project email list by emailing your name to firstname.lastname@example.org with “Powell” in the subject line. If you already receive emails on this project you don’t need to sign up again.
For More Information
Contact Rhetta Drennan at 503-823-6006.
Did you know?
All sewer design and construction projects depend on advance surveys of construction areas. Surveyors leave painted markings on streets and sidewalks which don’t mean a lot to most of us. Here’s a simple guide to help you decode them:
- White = proposed excavation
- Pink = temporary survey markings
- Red = electric power lines, cables, conduit and lighting cables
- Yellow = gas, oil, steam, petroleum or gaseous materials
- Blue = potable water
- Purple = reclaimed water, irrigation and slurry lines
- Green = sewer and drain lines
Environmental Services will post updated information on what to expect as this project moves closer to construction. Before construction starts, crews will be in the construction area surveying, moving gas and water lines, and drilling for soil samples.
During construction, city project team members will meet with the contractor weekly and the contractor will provide a two-week look ahead of the schedule. We will email those construction updates to people on the project email list and post updated information on this webpage.
Environmental Services will also mail another newsletter before construction begins with information about construction methods, the contractor, and what to expect throughout the process.
Trenchless Pipe Repair
Project engineers are proposing three trenchless construction methods for the pipe work along SE Powell Boulevard. Trenchless methods can reduce traffic impacts.
Jack and Bore - A boring machine pushes a large drill and new pipe from a sending pit through the ground to a receiving pit.
Pipe Bursting - A winch pulls a bursting head through the old pipe to break it apart and pulls a new pipe into place behind it.
Cured-in-Place Pipe - A flexible liner inserted inside the old pipe hardens to form a new interior pipe surface.
This project includes replacing undersized pipes to increase sewer system performance and capacity. This work will include excavating trenches in streets and using heavy construction equipment. During the construction phase, there will be traffic diversions and street closures. Environmental Services will notify residents well in advance of traffic disruptions and will work closely with neighbors and local businesses to minimize construction impacts.
Green streets are small rain gardens that collect stormwater runoff from streets and allow water to soak into the ground as soil and vegetation filter pollutants. Green streets also add neighborhood green space and slow traffic to improve pedestrian safety.
Vegetated curb extensions or street-side planters are the most common style of stormwater facilities. Portland has more than 1,000 green streets that effectively manage stormwater, alleviate basement flooding and improve neighborhood aesthetics. Go to www.portlandoregon.gov/bes/greenstreets to see green street examples and get more information.
The city’s goal is to locate green street planters where they will be most effective and have the smallest impact on parking. But based on the width of streets and planting strips and the locations of underground utilities and driveways, the city sites some green streets in the on-street parking zone next to the curb.
Green Street Care
Low-growing plants in green streets adapt to a variety of conditions. The city chooses plants for their hardiness and ability to filter pollutants from stormwater runoff. Neighbors will have the opportunity to help with the planting design. The city maintains green streets, which includes removing debris, weeding, watering, and replacing plants as needed. We also welcome help from neighbors with weeding, removing litter or watering, especially during hot weather. To learn more about how you can help as a volunteer Green Street Steward, visit www.portlandoregon.gov/bes/greenstreetsteward.