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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 removed trees and other vegetation to allow equipment to access the trestle. Because of this, we developed 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.
Happening now
We have finished strengthening the trestle that holds the water pipe running along Kelly Creek. Completion of this project means that Portland's and Gresham's water supply is now more resistant to earthquakes and floods.
By mid-June, we plan to:
- remove equipment and supplies
- remove the bridge over the creek
- remove the ramp on the southwest side of the project area
- clean up the site
- install erosion controls for the summer
At the beginning of this project, we removed trees and other vegetation to allow workers and equipment to access the trestle. We started re-planting this spring and will continue restoration efforts through 2023.
What to expect
Construction may be complete, but we're sticking around.
Our inspectors will be stopping by a few times over the summer to make sure erosion controls are in place. And, our planting team will be coming by to weed and check on the plants we put in over the winter. We will be back next winter to plant in the construction area. Growing a healthy greenspace will take a little time, but we're committed to leaving Kelly Creek better than we found it.
Employees and contractors will continue to follow all work zone safety and social distancing measures.
Revegetation schedule
Construction began in fall 2020. Please note that the dates listed below may change based on crew availability and weather.
Early summer 2021
- Construction wraps up
- Plant a sterile wheatgrass and place straw over dirt in the construction area and some easement areas to stabilize soil over the dry summer months
- Monitor existing plantings to ensure healthy growth
Fall 2021
- Restore easement areas according to agreement with property owners
- Monitor plantings to ensure healthy growth
Winter 2022 –spring 2024
- Plant trees and shrubs in the construction area
- Ongoing monitoring and maintenance
- More planting if needed in previously planted areas
Image credits
Blue Wildrye: "Poaceae - Elymus glaucus ss0p. glaucus - BLUE or WESTERN WILD RYE DS" by Toni Corelli is licensed under CC BY-NC-ND 2.0, via Flickr
Slender hairgrass: "Deschampsia_elongata" by Matt Lavin is licensed under CC BY SA-2.0, via Wikimedia Commons
California brome: "Bromus_carinatus_3861052158" by Matt Lavin is licensed under CC BY SA-2.0, via Wikimedia Commons
Cascara: "Rhamnus purshiana, Cascara -- branch with leaves, flowers and buds" Jesse Taylor is licensed under CC BY-SA 3.0, via Wikimedia Commons
Western hemlock: "Tsuga heterophylla eu 76 14062008 1" by Olivier Pichard is licensed under CC BY-SA 3.0, via Wikimedia Commons
Western red cedar: "Thuja_plicata_43569" by Walter Siegmund is licensed under CC BY-SA 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic license, via Wikimedia Commons
Snowberry: "Aeron yr Eira (Symphoricarpos rivularis-albus) Snowberry - geograph.org.uk – 553418" by Alan Fryer is licensed under CC BY-SA 2.0, via Wikimedia Commons
Thimbleberry: "Rubus_parviflorus_9481 (Thimbleberry)" by Walter Siegmund is licensed under CC BY-SA 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic license, via Wikimedia Commons
Serrulate penstemon: "640px-Penstemon-serratultus_1501" by Walter Siegmund is licensed under CC BY-SA 3.0, via Wikimedia Commons
Western columbine: "7180514174_39d570693a_q" by Franco Folini is licensed under CC BY-SA 2.0, via Flickr
Oregon iris: "Iris_Tenax" by David W. Barts, CC BY 2.5, via Wikipedia
Meadow checkermallow: "640px-Sidlacea_campestris_inflorescence" by Flowersinmyyard is licensed under CC BY-SA 4.0, via Wikimedia Commons
Goldenrod: "10169466724_143e101901_q_Goldenrod" by Pete O'Connor is licensed under CC BY-SA 2.0, via Flickr
Douglas aster: "29557110781_696a3de75_w_DouglasAster" by Linda, Fortuna Future is licensed under CC BY-NC 2.0, via Flickr