Heavy Rainfall Forces Switch to 100% Groundwater

Update November 29th, 2022: Portland Returns to 100 percent Bull Run Water

Friday’s massive rain event increased the output of streams feeding the Bull Run watershed, contributing to a rapid increase in extra organic material suspended in the water. As a precaution, the Portland Water Bureau has switched entirely to groundwater sourced from the Columbia South Shore Well Field. Last month, officials began blending Portland’s two water sources to compensate for low Bull Run water levels caused by dryer-than-normal weather. Now, excess precipitation has caused a complete dependence on underground water sources.

Almost a million people depend on water supplied by the Portland Water Bureau. Long-term investments have added well-water sources to the City’s water supply, creating greater resiliency to weather-related events. As the climate trends towards hotter and dryer patterns, groundwater reserves will become essential to water delivery. However, this investment is also valuable during storm conditions that push silt, debris, or other contaminants into the water system. The new Bull Run filtration facility should reduce the need to switch to groundwater after storms when it comes online in 2027. It will also remove disease-causing microorganisms that sometimes threaten drinking water safety.

The Portland Water Bureau assures residents that Columbia South Shore Well Field water supply meets or surpasses all federal and state drinking water regulations. However, they make it a policy to notify the public when activating groundwater sources so sensitive water users can take precautions. Ratepayers can sign up at the Portland Water Bureau’s website to receive notifications regarding changes to the water system. Customers with questions should call the Water Line at 503-823-7525 and watch for updates to this article when Portland’s water system returns to 100 percent Bull Run watershed-sourced water.