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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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Maintaining Our Assets: The Denver Tank

By Lindsay Wochnick Add a Comment

Cleaning the Tank

In April, Portland Water Bureau industrial painters climbed up 84-feet to reach the interior of the Denver Tank. Once inside, the painters carefully hand-lifted all of their equipment through the tank’s 84-foot intake pipe. 

With the support of operating engineers, the painters then cleaned the interior of the tank as part of Operation’s Periodic Maintenance Program. 

The team of painters and operating engineers were also joined by additional engineers who assessed the condition of the tank's coatings, structures, and safety equipment. 

Denver TankMore About the Denver Tank
Located in N Portland’s Overlook neighborhood, the Denver Tank stands 138-feet tall, stores three million gallons of water, and provides fire flow protection to all of Swan Island.

Built in 1961, the 55-year-old tank is Portland’s largest column supported elevated tank. Most column supported elevated tanks have a center column and one outer ring of columns. 

The Denver Tank has two concentric rings of columns and a center column.

Celebrate Nature in the City at Explorando el Columbia Slough

By Lindsay Wochnick Add a Comment

Join the Portland Water Bureau in celebrating the Columbia Slough! Explorando el Columbia Slough, a free Spanish/English family event, offers guided canoe trips, live music, folk dancing, storytelling, arts and crafts, workshops, and more.

Celebrate Nature in the City at Explorando el Columbia SloughThe Water Bureau sponsors Explorando because our water system relies in part on groundwater wells deep below the Columbia Slough Watershed. Family festivals like Explorando present a great opportunity to talk with Portlanders about where their drinking water comes from and how they can help protect it.

The first 300 visitors receive a free Explorando t-shirt. No registration necessary.

When: Saturday, June 11, 1 - 5 p.m.
Where: Whitaker Ponds Nature Park, 7040 NE 47th Ave., Portland

Kelly Butte Reservoir Project Honored with Concrete Award

By Lindsay Wochnick Add a Comment

Staff accepts Concrete Award
Staff from the Portland Water Bureau, MWH, and Hoffman Construction
accepted the award at an annual banquet.

The Oregon Concrete & Aggregate Producers Association (OCAPA) awarded the Portland Water Bureau’s Kelly Butte Reservoir project a 2016 Excellence In Concrete (EIC) Award.

The awards program began more than 30 years ago and continues today as a way to recognize concrete projects at the forefront of innovation and technology and showcase projects to inspire excellence in concrete design and construction.

Kelly Butte Reservoir 
Kelly Butte Reservoir, November 2015

The Kelly Butte Reservoir project began in late 2012 and was completed in 2016. The project replaced the 10-million-gallon aboveground water storage steel tank built in 1969 with a new, buried 25-million-gallon reinforced concrete reservoir. An overflow basin, multiple vaults, valve structures, access roads, and intricate network of underground piping were also constructed.

To construct the underground reservoir, basin, vaults, valve structures, and concrete encase all water pipes in and out of the facility, 16,000 cubic yards of high-strength concrete (3-5K PSI) was brought and poured onsite. Concrete placement for the structures and piping was required within a maximum of 60 minutes from the time of batch.


The reservoir’s floor and roof, each consisting of 266 20-feet by 20-feet squares, were poured in a checkerboard pattern in order to provide each square 14-days of continuously flowing water cure. The support columns also required a 7-day continuous flow water cure achieved with burlap and an elaborate network of piping and drip sprinklers.

The new underground reservoir consists of a 394 X 296 foot floor and roof, five walls, and 252 support columns. The reservoir has two cells, each with capacity to store 12.5-million-gallons of water. The cells were strategically built to operate independently, allowing for easy cleaning, inspection, and maintenance.

For the project, MWH Global was the structural engineer, Hoffman Construction Company the general contractor, Hoffman Structures the concrete subsidiary to Hoffman Construction Company, and CEMEX the concrete supplier.

The reservoir currently serves all of east Portland and will be a stopover for water supplied to the Washington Park reservoir and southwest Portland area water storage tanks.

The Water Bureau was also honored in 2015 with an EIC Award for the Forest Park Low Tank project which included the construction of a below ground 1.3 million gallon water storage tank and a 1,408 square foot pump station in NW Portland.

For additional information about the project, visit  

Washington Park Reservoir Improvements Project: May 2016 Update

By Lindsay Wochnick Add a Comment

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.

The project includes building a new, seismically reinforced below ground reservoir.

The new reservoir will preserve the historic drinking water function provided by the original reservoirs at the site and be engineered to withstand ongoing landslide encroachment and potentially catastrophic effects of a major earthquake. A reflecting pool/water feature will be constructed on top in the same general footprint as the historical Reservoir 3.

Reservoir 4 will be disconnected from the public drinking water system and a lowland wildlife habitat area, bioswale, and reflecting pool will be constructed in the basin.

When complete and online, the new underground reservoir will supply water to Portland’s west side and serve more than 360,000 people, including all downtown businesses and residents, the Oregon Zoo, more than 60 parks, three hospital complexes, and 20 Portland public schools. 


  • Proposed ScheduleJuly 1, 2016: Construction begins
  • December 31, 2019: New Reservoir 3 construction completed
  • December 31, 2020: Reservoir 4 disconnected from the public water system
  • 2023-2024: Project completed

The project will span eight years. The first two years (2016-2018) will trigger the most significant impacts to traffic, transportation, and parking in the park. Washington Park users are encouraged to travel to and move safely around the park and its attractions by using the bus and light rail, walking, biking and skating, and taking the free park shuttle. Visit and for transit options. 

Upcoming Work: Current – September 11, 2016 

Tree Pruning / Inspection Within project site, around the reservoirs, along SW Sacajawea Boulevard, SW Lewis Clark Way, & SW Madison Court          
Construction Fence Installation Within project site          
Placement of Mobile Field Offices Project site, below Reservoir 4          
Vegetation / Tree Removal Around the reservoirs, by SW Sacajawea and Sherwood Boulevards          
Erosion Control Within project site          
Disconnect Reservoir 3 Inlet and Outlet Piping Within project site          
Remove Weir Building Within project site, east of Reservoir 3          
Disconnect Reservoir 4 Inlet and Outlet Piping Within project site, by Reservoir 4          
Cut and Cap Piping Within project site, by Reservoir 4          
Removal of Stilling Tank inside Gatehouse 4 Within project site, by Gatehouse 4          
Construct Shoring Wall (begins mid-Sept) Within project site, by Reservoir 3          
DISCLAIMER: The chart is intended solely for general purposes and guidance only. Target dates for beginning and completion of each task are subject to change.

IMap showing traffic delay locationsmpacts: May – September 11, 2016

  • Traffic Delays: Travelers may experience intermittent traffic flow delays up to 20 minutes on SW Sacajawea and SW Sherwood Boulevards due to pre-construction maintenance and removal of vegetation and trees in the project site.
  • Parking: All parking will remain open on SW Lewis Clark Way and SW Sacajawea and SW Sherwood Boulevards.
  • Park Facilities: All park facilities will remain open.
  • TriMet Bus Service: TriMet Bus Line 63 may have minor delays. Stop ID 6177 at SW Sacajawea/ Sherwood may be intermittently affected depending on pre-construction activity. Check for real time updates.

The project is part of the Water Bureau’s Capital Improvement Program. It is funded by revenue bond proceeds backed by the utility ratepayers’ fund. Currently, 100 percent of the project’s design is complete. With high confidence, the Water Bureau now appraises the total project budget for the life of the project at $190 million (+/- 10 percent).

In May 2016, the Water Bureau project team presented to Portland City Council two financial items related to the project. 

  • Guaranteed Maximum Price Contract: The City Council voted in unanimous support of a Guaranteed Maximum Price (GMP) project contract with General Contractor Hoffman Construction Company (HCC). The approved GMP sets the construction contract’s maximum price at $152,181,850. Under this legal agreement, HCC will be compensated for actual costs incurred during the construction plus a fixed fee, subject to maximum amount noted above. Learn more here.
  • Community Benefits Plan: Council members reviewed and listened to public testimony on a Community Benefits Funding ordinance related to the project. The ordinance authorizes a one-time $1,145,500 dedicated fund amount from the project’s budget to create economic opportunities and benefits for Disadvantaged, Minority, Women, and Emerging Small Businesses (DMWESB) within the local community. City Council will vote on the ordinance June 1. Learn more here. 

KEEPING YOU UP-TO-DATE To contact us with questions or concerns or to change your preferences on how to receive project updates:

Dam Safety Lives Today: It's Not Just an Historic Event

By Lindsay Wochnick Add a Comment

National Dam Safety Awareness Day occurs on May 31 of each year, commemorating the failure of the South Fork Dam in Johnstown, Pennsylvania in 1889. This event resulted in the loss of more than 2,200 lives and is considered the worst dam failure in the history of the United States. 

While dams provide many benefits to communities, such as storage of drinking water and improvement of wildlife habitats, they can also pose a flood risk if they fail. Dam safety is a shared responsibility and everyone is encouraged to know their role and when to take action.

Dam 1 in the Bull Run Watershed 
Dam 1 in the Bull Run Watershed

The Portland Water Bureau owns seven major dams: two dams in the Bull Run Watershed, three Mt. Tabor Reservoir Dams, and two Washington Park Reservoir Dams. The Hydroelectric Power Section of the Water Bureau administers a dam safety program, assessing the stability of each of the dams and monitoring the structures for any sign of instability.

For each of those structures, periodic updated stability analyses are conducted, monitoring data is collected and analyzed, periodic inspections are conducted, and then Emergency Action Plans are updated and tested. 

National Dam Safety Awareness Day not only encourages and promotes responsibility for dam safety by both individuals and the community, but it’s a day to discuss and train on ways to prevent future catastrophic dam failures.