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Portland Water Bureau

From forest to faucet, we deliver the best drinking water in the world.


1120 SW Fifth Ave, Suite 600, Portland, OR 97204

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Mt. Tabor Reservoir Adjustment Project

  • Valve work on service road between Reservoir 5 and SE Lincoln Dr.

  • Disconnecting Piping inside Reservoir 1

  • Potholing downhill from Reservoir 1

  • Public Water Systems & Protection Measures Storing finished drinking water (water that is ready to be directly served to homes and businesses) in facilities that are completely exposed to the air and surrounding environment is no longer allowed by federal and state law.


In order to satisfy an unfunded federal water quality mandate, the City of Portland is required to disconnect Portland’s open air reservoirs, including three at Mt. Tabor Park. This work is scheduled to begin in Fall 2015. Reservoir 7, which is enclosed at Mt. Tabor Park, will stay in service.

Scope of Work
Several types of disconnection work are necessary. Some buried pipe will have to be removed, and some new pipe will be installed below ground. Other work will take place inside vaults, both above and below ground, and other structures. None of this work will damage or make non-reversible alterations to the open reservoirs or other historic structures.

Main Tasks
Three major tasks are proposed:

  1. Water pipes leaving the open reservoirs will be disconnected, leaving an “air-gap” between the reservoirs, dead-end lengths of pipe and the active water system. This generally involves a "cut and plug" which entails removing approximately a 10-foot section of pipe, and then closing the openings. It is important to note that this disconnection will not prevent water from entering the reservoirs in the future. Existing large-diameter pipes will allow water to flow into the reservoirs, but water will flow to the sewer system rather than the water distribution system when it leaves the reservoirs.

  2. A new transmission pipeline will be constructed between a supply conduit on the south side of Mt. Tabor and the transmission pipeline located in SE Lincoln, west of the park.

  3. When the project is complete, all reservoirs will have water in them that will be periodically drained and refreshed.

Click here for the Mt. Tabor Adjustments Project brochure.

For more information or for questions, contact Terry Black, Sr. Community Outreach and Information Representative at 503-823-1168.



Project Details: Maps and Photos of Work Areas

During the proposed construction both inside the park and on the nearby street, the Portland Water Bureau and its contractor will work to protect trees and the reservoir and park facilities not impacted by the work.

Project Updates

This page was created for this project website to share more information and offer ongoing updates for both the Land Use Review processes and construction schedules. Project updates and schedules will be posted on a regular basis so that the public will know where to expect temporary construction impacts while visiting the park.