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Portland Water Bureau

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GENERAL INFORMATION: 503-823-7404

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

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Washington Park Reservoir Improvements Project

  • Washington Park Reservoirs 3 & 4 The Water Bureau supplies drinking water to more than 950,000 people in the Portland metropolitan region. A large capacity reservoir at Washington Park is an essential part of Portland’s water system, serving areas west of the Willamette River.

  • Washington Park Reservoir Improvements Project In order to comply with federal and state mandates, and ensure a healthy, resilient, and secure water system, the Portland Water Bureau is moving forward with a project to update the Washington Park reservoir site.

  • Upper Reservoir 3 The community proposed concept for the Reservoir 3 site includes building a new below-ground reservoir in the same general footprint as the existing upper Reservoir 3, with a reflecting pool on top.This reservoir would be built east of the landslide.

  • Upper Reservoir 3 The community proposed concept for the Reservoir 3 site includes building a new below-ground reservoir in the same general footprint as the existing upper Reservoir 3, with a reflecting pool on top. This reservoir would be built east of the landslide.

  • Lower Reservoir 4 The Washington Park Reservoir Project proposes to disconnect Reservoir 4 from the public drinking water system. The community proposed concept for the Reservoir 4 site includes a lowland habitat area/bioswale & a reflecting pool in the Reservoir 4 basin.

  • Lower Reservoir 4 The Washington Park Reservoir Project proposes to disconnect Reservoir 4 from the public drinking water system. The community proposed concept for the Reservoir 4 site includes a lowland habitat area/bioswale & a reflecting pool in the Reservoir 4 basin.

  • Community Outreach & Engagement The Water Bureau is dedicated to providing members of the public with project information, progress updates, and opportunities to participate effectively in the design and planning process.

  • Land Use Review Applications This project will undergo three Land Use Review Reviews: Type IV Demolition, Type III Historic Resource, and Type III Conditional Use and Environmental reviews. Before work permits are issued or construction begins, all LUR applications must be approved.

Washington Park Reservoir Improvements Project logo 

PROJECT UPDATES
Click here to keep up to date on the Washington Park Reservoir Improvements Project's progress.

In order to comply with federal and state mandates and ensure a healthy, resilient, and secure water system, the Portland Water Bureau and Oregon general contractor Hoffman Construction Company are moving forward with an eight-year capital improvement project to update the Washington Park reservoir site at 2403 SW Jefferson Street.

Currently, Washington Park’s open Reservoirs 3 (upper) and 4 (lower) occupy the site along with two gate houses, a weir building, three pump houses, a generator house, and associated underground piping. The reservoirs are part of an ingenious gravity‐fed drinking water system constructed more than 120 years ago in 1893 and 1894, respectively.

Project Background

Reservoir 3 from the Grand Stairway: Existing 
Left - Existing: Reservoir 3 from the Grand Stairway
Right - New Construction: Upper Reflecting Pool from the Grand Stairway

Reservoir 3 with Gate House 3: Existing 
Left - Existing: Reservoir 3 with Gate House 3
Right - New Construction: Upper Reflecting Pool at Gate House 3

The Washington Park Reservoir Improvements Project entails building a new, seismically reinforced below ground reservoir. The reservoir will not only maintain the historic drinking water function provided by the original reservoirs, but will be engineered to withstand ongoing landslide encroachment and potentially catastrophic effects of a major earthquake and will feature a reflecting pool on top in the same general footprint as the historical Reservoir 3.

 Reservoir 4 View from Dam 3: Existing 
Left - Existing: Reservoir 4 View from Dam 3
Right - New Construction: Lower Reflecting Pool View from Dam 3

Reservoir 4 View from Above at Sherwood Blvd: Existing 
Left - Existing: Reservoir 4 View from Above at SW Sherwood Blvd
Right - New Construction: Lower Reflecting Pool View from SW Sherwood Blvd

Reservoir 4 will be disconnected from the public drinking water system, and a lowland habitat area/bioswale and a reflecting pool will be constructed in the basin. Work will primarily be within the Historic District.

When complete and online, the new underground reservoir will supply water to Portland’s west side, including all downtown businesses and residents, the Oregon Zoo, more than 60 parks, six hospitals, and 20 Portland public schools.

The project is part of the Water Bureau’s Capital Improvement Program and funded by revenue bond proceeds paid back with utility ratepayers’ fund.

Timeline

  • May – September 2016: Early site preparation work, including construction fencing installation, placement of mobile field offices, tree/vegetation clearing, and erosion control measures
  • September 2016 – December 2019: Major earthwork and Reservoir 3 construction
  • January 2020 – December 2021: A two-year pause in construction, allowing soils to consolidate to reduce any vertical movement that would affect the reflecting pool and other surface features.
  • January 2022 – December 2023: Construction of interpretive features, including the two reflecting pools

Project Drivers

Four major challenges are driving this project:

  1. Aging Facilities: Reservoirs are typically designed for 100 years of service. The two Washington Park reservoirs are more than 120 years old. Condition assessments performed at the Washington Park Reservoir site in 1997 and 2001 confirmed the reservoirs and structures were nearing the end of their useful service life.
  2. Seismic Vulnerability: The original facilities were designed and constructed prior to current seismic standards. They do not meet structural requirements for current anticipated seismic activity and, therefore, are vulnerable to severe damage or failure during a significant seismic event. Failure of these reservoirs and structures could be catastrophic, resulting in the loss of drinking water to the west side of Portland.
  3. Landslide: Washington Park’s ancient landslide at the reservoir site has been continuously damaging both reservoirs since original construction in the late 1800’s.
  4. Long-Term Enhanced Surface Water Treatment Rule (LT2): The 2006 federal regulation requires the City of Portland to protect its stored drinking water against contamination as part of the water quality requirements for safe drinking water. To address this requirement, the City is constructing alternative buried storage, allowing the uncovered reservoirs to be taken off‐line.

Land Use Reviews

The project underwent three Land Use Reviews (LUR):

The applications are a result of a robust public involvement process that included multiple public open houses, nine (9) Community Sounding Board (CSB) meetings that guided design for the required visible features of a new reservoir in Washington Park and five (5) public hearings before the Historic Landmarks Commission. Learn more about the LUR Application process here.

Historic Designation

The Washington Park Reservoirs Historic District was listed on the National Historic Registry on January 15, 2004. This means that the proposed work is regulated as in a historic district under City Titles 33.445.300, 33.445.320 and 33.846.  The area for the project includes Portland Water Bureau facilities that are both inside and outside the Reservoirs Historic District.

 

Project Area

The project work will be located at 2403 SW Jefferson Street, Portland, Oregon. The area is roughly bounded by SW Jefferson St. near the TriMet tunnel and Madison Trail on the east, by SW Lewis and Clark Circle on the north, by SW Oxford Road on the west and by fencing in the woods within Washington Park on the southwest and south. The project area surrounds and includes the two Washington Park reservoirs and related piping, vaults and pumping facilities, and landscaping that are operated and maintained by the Portland Water Bureau.

Reservoir 3 holds approximately 16.4 million gallons of water when full and Reservoir 4 holds 17.6 million gallons. These reservoirs are an essential part of the water system serving areas west of the Willamette River in the city.  The pumping facilities on the site ensure water can reach high elevations in the west hills.

The reservoirs, dams, and gatehouse were constructed in the late 1800s, with accessory structures completed slightly later. The area is landscaped with a variety of ground covers, trees and shrubs consistent with the reservoir location within Washington Park. Several of the operational and decorative structures and elements within the Reservoirs Historic District are considered to be “contributing structures” in the National Historic Listing. The project area in the Reservoirs Historic District is surrounded by a chain link fence (the boundary of the Reservoirs Historic District is contiguous with or is just outside this fence in most locations).

Outside the Reservoirs Historic District, the project area includes vaults and piping that are in paved areas near Portland Water Bureau facilities or along Madison Trail, and pavement and gates on Madison Trail. Madison Trail serves as a maintenance road for the Portland Water Bureau and Portland Parks & Recreation, and as a bike and pedestrian path within the park. It is not a public right of way. Several public walkways and trails traverse the project area outside the Reservoirs Historic District and intersect Madison Trail.

The Arlington Heights Neighborhood is to the north and west of the project area, and Goose Hollow Neighborhood is to the east.

Keeping You Up-To-Date

The Water Bureau will post a monthly project update and schedule of upcoming project work. To receive these updates directly to your e-mail, click here and register.

Your Feedback is Important

Please contact us at your convenience with questions, concerns, or comments:

Thank you for your cooperation and understanding during this important capital improvement project. As always, we’ll strive to provide quick responses to your concerns, minimal disruption near your residence or business, and open and clear communication with you throughout the project.


Offer Your Feedback

Your feedback is important. Submit project questions, comments, and/or concerns online to the Water Bureau.