Elk Rock Pump Station Project

Sewer and Stormwater

Active

Environmental Service is in construction on a project to upgrade the Elk Rock Pump Station. The existing pump station will be expanded to increase storage and pumping capacity while improving reliability and safety. This upgrade will protect public health and the environment.

Construction began in March 2025 and will take up to two years to complete.

Project Area

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What's Happening Now

Schedule

In January 2026, crews will be installing a new permanent power connection to the pump station property. This will requiring digging a trench in the cul-de-sac and removing a few concrete sidewalk panels. The sidewalk and the trench in the cul-de-sac will be repaired shortly after the permanent power is installed and inspected by PGE.

ORR Construction has closed the cul-de-sac at the end of S Riverwood Rd. The closer will be intermittent throughout the project. Most of the work will take place within the pump station property, there may be times where crews will need to work in the right-of-way.

Landscape and Delivery Vehicles

Large vehicles, like landscaping companies with trailers will not be able to use the cul-de-sac to turn around. There will be traffic control signage at multiple locations, and we ask that you please inform these landscape companies and delivery drivers when you see them about the closure. This will help minimize disruptions so that the crews can quickly and safely complete the repairs.

What to Expect During Construction

Construction hours are Monday through Friday from 7 a.m. to 6 p.m. Work may be done on some Saturdays, as well.

The cul-de-sac at the end of S Riverwood Dr. will be closed periodically throughout construction. Please follow all traffic control signage while traveling in the area. Below is a list of impacts and activities that you can expect to see during construction:

Noise, vibration, dust
Traffic delays
Parking restrictions
Equipment storage
Continued sewer service during the work
Access to your home or business will be maintained

To learn more about the What to Expect During Construction webpage.

Project Background

The Elk Rock Pump Station collects sewage and stormwater from neighboring properties and from two smaller pump stations in the area. It then pumps those combined flows to the Tryon Creek Wastewater Treatment Plant. The pump station is operated and maintained by the City of Portland and also serves Dunthorpe Riverdale Service District.

Since the pump station was built in 1981, the City has constructed a number of upgrades, including rebuilding the pumps in 2002 and general site upgrades for maintenance access and safety. This new upgrade project will make additional improvements.

Pump Station Improvements

Planned improvements to the pump station include the following:

The existing belowground wet well and dry pit will be reconfigured into one, larger wet well to increased storage capacity.
The existing generator building will be repurposed to house electrical and controls equipment and include a restroom for maintenance staff.
A new belowground valve vault will be installed adjacent to the wet well.
A new stand-by generator and pigging system will be installed adjacent to the existing building.
All mechanical, electrical, and control equipment and systems will be replaced.
A new stormwater outfall will be constructed between the pump station and the river to re-route stormwater collected in the cul-de-sac.
The existing fence and gate will be replaced with added length and increased security.
Existing trees will be protected, and new native and landscaped vegetation will be planted surrounding the expanded facility.

What is a Pump Station

Sewage, which is 99 percent water, flows downhill, and gravity is the main force that moves sewage through pipes. However, in low-elevation areas or where sewage needs to go uphill, pump stations push the sewage up so that gravity can take over again. Portland has nearly 100 pump stations with large underground tanks (also known as wet wells) in low-elevation areas. Pump stations are equipped with specialized pipes that are built to handle the force of sewage being pushed through them. Pump stations also have equipment that helps control odor and protects the pumps. Visit our About Our Sewer and Stormwater System page to see how pump stations fit into the larger public sewer and wastewater system