Gresham trestle upgrades

Construction type

Water

Project status

Active

This project will strengthen the structural supports (known as trestles) that hold a water pipe near Kelly Creek and Beaver Creek in Gresham.

Fall 2020 to spring 2022 (vegetation monitoring continues through 2024)

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Project overview

Not if, but when... You've heard about our region's earthquake risks. The Water Bureau has worked for the past several decades to increase the number of water supply facilities that can withstand earthquakes. The Gresham trestle replacement project is part of our commitment to preparedness and our mission of serving excellent water every minute of every day.

This project will strengthen the structural supports (known as trestles) that hold the water pipe that runs along Kelly Creek in Gresham. Both the pipe and trestles were installed here in 1911. The pipe is in good condition, but the trestles might not endure a large earthquake or heavy flooding. The work we're doing will make Portland's and Gresham's water supply more resistant to earthquakes and floods.

As part of the project, we will remove trees and other vegetation to allow equipment to access the trestle. We will then follow an extensive restoration plan developed with the City of Gresham. After construction, crews will landscape the entire lot with native trees and plants that will improve the health of the creek.

This map shows the construction area near Kelly Creek, as well as equipment and personnel entrances on SE La Mesa Court and NE El Camino Drive.

Happening now

The contractor working on the Gresham Trestle Project is also helping the Water Bureau install a large, seismically resilient pipe that will serve water to all of downtown Portland. A portion of that pipe is being installed in a major thoroughfare downtown where the Portland Bureau of Transportation (PBOT) is also working on a project. We are coordinating our efforts so that when PBOT tears up the section of street where our pipe goes in, we will quickly install our pipe. This means we only have to disrupt traffic once and we save money on both projects.

Based on the status of that project, we and the contractor plan to return to work on the trestle in mid-March. In the meantime, planting crews have begun restoring vegetation on site. Here's what we're up to:

Planting trees, shrubs, and grasses in the open space between the construction site and NE El Camino Drive—February to March 2021: We are planting now so that the grasses, trees, and shrubs will be fed by spring rains and ready for when the dry weather of summer begins.
Restoring easement areas—late spring 2021: Once we finish work in the construction area, we will restore the easement areas according to our agreements with the property owners who have provided us with access to the worksite.
Planting sequence change for construction area:Meadow with wildflowers this summer, then shrubs and trees in fall 2021: Because we're getting a later start on planting inside of the construction zone, we're going to wait to plant the trees and shrubs until fall. This is so that the young plants will get more water during the rainy season and have a better chance of survival. We want our neighbors to have something pleasant to look at in the meantime, so we are planting a specially formulated native grass and flower mix.

During the next phase, we will build the new footings, or base, of the trestle. These footings will be made from rebar and concrete and will connect foundation to the trestle above. Afterward, we'll secure the conduit to the footings using welded steel brackets known as bents. Later in 2021, we'll begin site cleanup and continue the revegetation phase.

What to expect

Work hours: Monday to Friday, 7:00 am to 4:30 pm
Noise: Work will remain quiet until March aside from employees communicating with each other while planting.
Parking: Employees will use some on-street parking spaces. Most equipment and supplies will be stored on the construction site, but some may be stored in the street to limit our impact on the creek.
Access: Workers will access the site from Southeast La Mesa Court and Northeast El Camino Drive. Equipment will be brought on site via Southeast La Mesa Court.
Service access: Mail, garbage and delivery services will have access. This work will not disrupt your water service.

Work may be delayed if staffing availability or construction resources change due to current events. Employees and contractors will continue to follow all work zone safety and social distancing measures.

Protecting the creek

We know you care about Kelly Creek—we do, too! We worked closely with the City of Gresham to develop a site-specific erosion control and restoration plan. Our crews are required to mark and put protective fencing around specific trees, install erosion control along the stream, and plant native grasses to help stabilize the hillside. We will also remove invasive plants by hand and by spot application of herbicide. When the project is done, we will plant the entire lot (not just the work site) with native trees, shrubs, and grasses.

Construction and revegetation schedule

Map showing the three different replanting areas described in the text.

Construction began in fall 2020. Please note that the dates listed below may change based on crew availability and weather.

Winter/spring 2021

Pictures of the different types of grasses that will be used in re-seeding the open space to prevent erosion, including (left to right) Blue wildrye, slender hairgrass, and California brome. — Photos of native grasses that will be used in reseeding the area, including (left to right) blue wildrye, slender hairgrass, and California brome.

Shrub, grass, and tree planting in the open space between the construction site and Northeast El Camino Drive.

Spring/early Summer 2021 

Construction wraps up
Planting grasses and wildflowers in the construction area and restoring the easement areas
Monitoring plantings to ensure healthy growth
Removal of erosion controls