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Portland Water Bureau

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Proposed Mt. Tabor Reservoir Project

  • Mt. Tabor Park is a Historic Community Asset and an Important Part of our Parks System

    The reservoir structures and buildings at Mt. Tabor Park are historically significant because of their role in Portland’s early water system.

  • 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.

  • Open Drinking Water Reservoirs

    The Mount Tabor Reservoirs were built during the period of 1894 and 1911, along with the reservoirs in Washington Park.


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 early 2015. Reservoir 7, which is enclosed at Mt. Tabor Park, will stay in service.

Video Overview of Proposed Project

Proposed Project – 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 entering and leaving the open reservoirs will be disconnected, leaving an “air-gap” between the reservoirs and the water system. This generally involves a "cut and plug" which entails removing a section of pipe and then closing the opening. 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.  New connections will be made between some large diameter transmission pipelines to allow the water to be rerouted around the reservoirs.

3.  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.

The park area south and southwest of the smaller open Reservoir 1 will be temporarily closed in order to make the new connection between the supply conduits that will allow water to bypass the reservoirs. This work will take about three months to complete.Mt Tabor map VIEW THE PROPOSED WORK AREAS & PIPE ALIGNMENTS.    

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 exposed to the air and surrounding environment is no longer allowed by federal and state law. It is also not recommended by public health agencies, including the Multnomah County Health Department, which has recommended that all uncovered finished drinking water storage facilities be removed from Portland’s drinking water system.

The federal Environmental Protection Agency (EPA) has determined that storing finished drinking water in uncovered reservoirs exposes the water to contamination from animal and bird waste, airborne pollutants, litter and vandalism. EPA has established a new national drinking water regulation that prohibits the use of uncovered reservoirs for finished drinking water storage. This regulation is known as LT2 (the Long Term 2 Enhanced Surface Water Treatment Rule; 40 CFR_141.713 & 141.714).

LT2 prohibits the use of open reservoirs for finished drinking water. In order to continue using an open reservoir, a water provider would either have to cover the reservoir so that it is not exposed to the air, or install water treatment facilities at each reservoir outlet. (Our water is not treated in this way anywhere in our system.)

In 2009, the City Council adopted a strategy for complying with LT2. The strategy was later accepted by EPA. That strategy includes building new underground storage elsewhere and disconnecting the open reservoirs at Mt. Tabor.

The deadline for disconnecting the open reservoirs at Mt. Tabor Reservoir is December 31, 2015. The new storage under construction at Powell Butte and Kelly Butte will provide Portland customers with reliable, seismically sound local storage for the next century. LEARN MORE ABOUT THIS MANDATE.

Reviewing Proposed Work
In 2014, the proposed project will undergo an administrative land use review by the City’s Bureau of Development Services. The project will follow a Type 3 land use review process. This project has two Land Use Reviews – Historic Resource and Environmental – which will be consolidated into one application package and will be heard together by the Historic Landmarks Commission. The reviews will include a public hearing, public notices, and opportunities for public comment. ACCESS AN OVERVIEW OF THE LAND USE PROCESS

Get Involved
We are committed to meaningful public involvement as an essential element of this proposed project. More information about how to can lend your voice is below. PARTNERSHIP & FEEDBACK OPPORTUNITIES AVAILABLE.

Future of Mt. Tabor Reservoir Sites
Portland Parks & Recreation Commissioner Amanda Fritz and Portland Water Bureau Commissioner Nick Fish are leading the process to determine the future of this part of the park.

UPDATE: On December 4, Portland Parks and Recreation announced postponement of the December 10 Mt. Tabor Reservoir meeting until the land use review process is completed.

  • City Council Presentation: At the Portland City Council meeting on Wednesday, November 12 at 9:30 a.m. at City Hall, 1221 SW Fourth Avenue, two upcoming public meetings will be announced.  Representatives from Portland Parks & Recreation will describe the options to be presented at these meetings, and Portland Water Bureau staff will be on hand to answer technical questions of Council. Public testimony will not be taken at the Council presentation. Commissioners Fritz and Fish will bring an Action Item to Council in 2015 after considering community input on the future of the Mt. Tabor Reservoirs.
  • Public Meetings: On Tuesday, November 18 and Wednesday, December 10 (postponed), Commissioners Amanda Fritz and Nick Fish will host public meetings about the future of the reservoir sites. At the first meeting, City staff will describe possible futures for the reservoirs, and at the second meeting the Commissioners will announce the option they’ve chosen. The meetings will both be held from 6:30 to 8:30 p.m. in the McGuire Auditorium at Warner Pacific College, 2219 SE 68th Avenue. Public testimony is welcomed.

If you have questions, please visit Questions? Who to Ask

Get Involved

We will offer several opportunities for community members to learn more about this project and weigh in with feedback.

Land Use Review Process

The City of Portland's Land Use Review process, administered by the Bureau of Development Service, is designed to provide the public with appropriate notification, information, and opportunities to comment before final land use decisions are rendered.

Maps & Photos: Aerial & Street Level View of Proposed 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.

Map: Mt. Tabor Park Management Authority Boundaries (2008 Council Ordinance #182457)

Note yellow area showing designated park management authority was reversed in subsequent council decision; the area is now under Water Bureau management.

Frequently Asked Questions (FAQ)

The FAQs we have developed are designed to provide a better understanding of the proposed project and schedule, construction impacts, preservation, public feedback opportunities, costs, park amenities, and long-term planning.

History of Mount Tabor

Mt. Tabor Park is a historic community asset and an important part of our parks system.