Reservoir 1 in drawdown, July 2015
The U.S. Drought Monitor identified Portland as experiencing a moderate drought in its weekly map of drought conditions last week.
It is important for Portland metro area water users to note that while the Drought Monitor has made its assessment based on factors including local stream flows, temperature and soil moisture, Portland does not have a water supply shortage.
The report itself explains, “Municipal water supplies for the metropolitan areas of western Oregon and Washington are adequate even though the other indicators are showing intense drought development, especially over the last two months.”
Portland’s water source, the Bull Run Watershed, is a low-elevation watershed that gets its water primarily from rain, not snow. The watershed gets approximately 135 inches of rain each year, about 3-4 times more rain than we get here in town.
Thanks to careful planning, the Portland area has a high-quality secondary water source. The Columbia South Shore Well Field can be used in addition to the Bull Run supply during dry periods.
The Bull Run watershed, in combination with the Columbia South Shore Well Field, is capable of meeting Portland’s water needs throughout the summer.
A Q&A about Portland’s water supply can be viewed here. You can also find updates at the Portland Water Bureau’s Seasonal Water Supply Planning webpage.
The U.S. Drought Monitor is produced by the National Oceanic and Atmospheric Administration, the U.S. Department of Agriculture and the National Drought Mitigation Center at the University of Nebraska-Lincoln.