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The City of Portland, Oregon

Portland Water Bureau

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Historical climate trends in the Bull Run Watershed

The Bull Run Watershed is a great primary water source. The temperate rain forest gets as much as four times the precipitation of notoriously rainy Portland. However, despite the abundant and reliable rainfall, the watershed has experienced the impacts of a warmer climate.

Benjamin Beal, a Water Resource Modeler at the Water Bureau, analyzed environmental data to determine  long-term climate and hydrology trends in the Bull Run Watershed. Beal’s analysis identified significant trends of increasing air temperatures, decreasing summer streamflows, and increasing water temperature in streams throughout the Bull Run.

Maximum and minimum air temperatures have increased by 2°F to 3°F since the early 1900s, with winter and summer having the highest seasonal rates of rising air temperature. Bull Run water temperatures have increased at an annual rate of 0.01°C to 0.02°C, with a summertime increase of 0.03°C .

The plots below show decreasing summer streamflows over the past 40 to 50 years. Lower summer  flows have implications for summer water supply availability. A definitive cause of these reduced streamflows remains a question of interest to bureau researchers, but climate change is likely an important factor.

“To me, this sort of analysis is a local reminder that the Pacific Northwest is not immune to the effects of climate change and that we have already been impacted, whether we realize it or not,” says Beal.

Although the population of Portland is growing, the demand for water has been declining. Over the last decade, demand has fallen 16% from 109 gallons per capita per day in FY 2008–09 to 90 gallons per capita per day in FY 2018–19.

While the average customer being more water-wise helps stretch water supplies during the summer months, the bureau has still had to pump significant amounts of groundwater to meet water demands as recently as 2015 and 2018 in response to  earlier than usual dry seasons. Bull Run will likely experience similar stressful water supply years in a warmer future. Continued investments in Portland’s groundwater system are needed to make the entire water system more resilient in the face of these future stressors.

“The decline in summer streamflows has significant implications for our future summer supply,” said Kavita Heyn, the bureau’s Climate Science and Adaptation Program Manager. “We need to recognize the vulnerability of the Bull Run supply to warmer and drier conditions, and ensure we have a reliable groundwater supply, that together with Bull Run, can meet water demands.”

graphs showing a decreasing trend in streamflow

The plots show a decreasing streamflow trend in four of the Water Bureau’s primary stream flow gages for the hydrologic summer, which spans July, August, and September. The y-axis shows flows in cubic feet per second, and the x-axis shows the average monthly flow for a given year. 

Cryptosporidium Monitoring Update: Detections from routine monitoring in the Bull Run. Customers do not need to take any additional precautions at this time.

Since 2017, the Portland Water Bureau has detected low levels of Cryptosporidium from routine monitoring. These detections are more common during the rainy season and not unexpected after the recent rains. Results from recent monitoring were received from the Bull Run Watershed intake for Cryptosporidium, a potentially disease-causing microorganism. One Cryptosporidium oocyst was detected in the 50-liters collected on Sunday, Oct. 18. Prior to this detection, Cryptosporidium was last detected from the Bull Run Watershed intake on July 5, 2020, when one oocyst was detected from the 50-liters sampled.

The Bull Run watershed is Portland’s primary source of drinking water. The Portland Water Bureau does not currently treat for Cryptosporidium, but is required to do so under drinking water regulations. Portland is working to install filtration by September 2027 under a compliance schedule with Oregon Health Authority. In the meantime, Portland Water Bureau is implementing interim measures such as watershed protection and additional monitoring to protect public health. Consultation with public health officials has concluded that at this time, customers do not need to take any additional precautions.

Exposure to Cryptosporidium can cause cryptosporidiosis, a serious illness. Symptoms can include diarrhea, vomiting, fever and stomach pain. People with healthy immune systems recover without medical treatment. According to the Centers for Disease Control and Prevention (CDC), people with severely weakened immune systems are at risk for more serious disease. Symptoms may be more severe and could lead to serious or life-threatening illness. Examples of people with weakened immune systems include those with AIDS; those with inherited diseases that affect the immune system; and cancer and transplant patients who are taking certain immunosuppressive drugs.

The Environmental Protection Agency (EPA) has estimated that a small percentage of the population could experience gastro-intestinal illness from Cryptosporidium and advises that customers who are immunocompromised and receive their drinking water from the Bull Run Watershed consult with their healthcare professional about the safety of drinking the tap water. The Portland Water Bureau and Burlington, City of Gresham, City of Sandy, City of Tualatin, Green Valley, GNR, Hideaway Hills, Lake Grove, Lorna Domestic Water, Lusted, Palatine Hill, Pleasant Home, Raleigh, Rockwood, Skyview Acres, Tualatin Valley, Two Rivers, Valley View and West Slope Water Districts receive all or part of their drinking water supply from the Bull Run. To learn if your drinking water comes from Bull Run, please contact your local drinking water provider.

The public and the media are encouraged to view all sampling results posted to the City’s website at The bureau will notify the media and public immediately should further test results indicate a risk to public health and precautions are necessary.

Customers with questions regarding water quality can call the Water Line at 503-823-7525.


The Portland Water Bureau serves water to almost a million people in the Portland area. Portland’s water system includes two great water sources, 53 tanks and reservoirs, and 2,200 miles of pipes. With 600 employees working on everything from water treatment to customer service, the Water Bureau is committed to serving excellent water every minute of every day.

SPUR Small Business Spotlight: DĀNWÈI CĀNTĪNG 

Kyo Koo, Head Chef of Danwei CantingInspired by the flavors and culture of Northern China, Kyo Koo, head chef of Danwei Canting, fills a unique niche in Portland’s restaurant scene. For the past three years, Koo has provided a contemporary take on traditional Chinese cooking, allowing Portlanders to savor the flavors and nostalgia of Beijing.  

With most of their revenue coming from dine-in service, Koo says the pandemic has heavily impacted the restaurant’s business model.  

“The lockdown was a complete 180. We went takeout and delivery only,” Koo said. “Sales fell immediately and there were a few weeks of uncertainty surrounding our future.”  

One of Danwei Canting’s biggest challenges has been finding ways to support their front-of-house staff, who make a living off tips. Koo explained that with the SPUR credits covering utility costs, the restaurant will be able to adapt to changing expenses as a result of COVID-19 restrictions.  

“Packaging costs have become a much larger part of our budget with the shift from dine-in to mostly takeout and delivery” said Koo. “The extra funds from the utility credit will allow us to increase tip share, boost morale, and overall support a really great group of employees.” 

Most recently, Koo competed in the Food Network’s Chopped Challenge and won, becoming a Chopped Champion. The episode is available on Danwei Canting’s website, where Chef Koo takes on Loco Moco, a Hawaiian comfort food in the appetizer round, pom pom mushrooms in the entree roundand an unusual coffee and crunchy cake in the final dessert round.  

Danwei Canting is one of more than 500 small businesses that received one-time credits through the Small Business Program for Utility Relief (SPUR). 


Customer Alert: System maintenance will affect bill pay site

Payments on our view/pay bill website will be affected by system maintenance two different times in the next week.

On Sunday October 18th, payments made on our view/pay bill website and 24-hour automated payment line between 2:00 a.m. and 5:00 a.m. may not post on your account until later in the day.

On Tuesday October 20th, between 6:30 p.m. and 8:30 p.m., customers will be unable to access our view/pay bill website or our 24-hour automated payment line. We apologize for the inconvenience.

Preparing for Climate Change

Climate changegroundwater pump station at sunset in the Pacific Northwest has become more apparent than ever before. Portland has experienced more days above 90 °F in the past decade than in any other decade since the 1930s.  The entire Pacific Northwest has warmed about 2 °F since 1900, and 2015 still stands out as Oregon’s warmest year on record. 

Droughts and natural disasters have been happening throughout history, but what were once-in-a-lifetime events are happening more frequently. The reality of a warming planet and changing weather patterns are clear. It’s a future the Portland Water Bureau has worked decades to prepare for.  

“With two water sources capable of meeting base water demands, Portland is well equipped to face the most pressing drinking water challenges of climate change,” said Edward Campbell, Director of Resource Protection and Planning. “The Bull Run River and the Columbia South Shore Well Field aquifers provide long term flexibility and adaptability for the Water Bureau in meeting its core mission. ” 

Kavita Heyn is the bureau’s Climate Science and Adaptation Program Manager. As a strategist leading  the bureau’s work on climate change, she collaborates with a wide array of people at the bureau, in the City, and throughout the water industry. Portland is seen as an industry leader in its climate adaptation work in part because of Kavita’s active collaboration with leading peer utilities via the Water Utility Climate Alliance.

Guiding the Water Bureau’s ongoing work is the Five-Year Strategic Plan, which was completed in 2019. It takes a risk-based approach to identifying vulnerabilities facing the water system. Director Gabe Solmer says climate work is one of her chief priorities.  “We look at what those risks are and we kind of flip around that negative to look at what are the strategies we’re going to use to mitigate those risks,” Solmer said. “We can take a closer look and put critical importance on the climate change work that we do so well at the bureau and the actions that we take that have a real impact.”