By 2050, Oregon’s annual demand for water will increase by 1.3 million acre feet — enough to fill 650,000 Olympic swimming pools, according to state water regulators.
That’s an increase of roughly 15 percent from today’s annual usage of about 8.425 million acre feet.
Oregon’s agricultural industry, which uses about 85 percent of the state’s water, is expected to need 6 to 9 percent more water over the next 35 years because growing seasons are expected to become longer and warmer, according to the Oregon Water Resources Department.
Due to a projected population increase of 1.5 million people, Oregon’s municipal and industrial water use is projected to grow by 20 percent by 2050, according to the agency’s findings.
Based on crop and irrigation trends, the southeastern portion of the state will likely see the greatest increase in water demand, particularly Klamath, Lake and Harney counties, said Rachel Lovellford, a hydrologist with the department, during the Nov. 20 meeting of the Oregon Water Resources Commission.
As average annual temperatures are expected to rise — between 2 and 8 degrees Fahrenheit, according to the department — crops will require more water earlier in the season, Lovellford said.
Farmers of alfalfa, for example, are expected to increase the number of cuttings they harvest each year, she said.
Meanwhile, growers are expected to become more dependent on irrigation, rather than rainfall, Lovellford said.
Currently, rainfall accounts for 30 percent of water needs of Oregon crops, while irrigation provides 70 percent, she said.
That ratio is expected to shift to between 26 and 29 percent rainfall and 71 and 74 percent irrigation by 2050, Lovellford said.
The agency arrived at its conclusions by analyzing several climate scenarios under which the state would experience a range of temperature increases and changes in precipitation, she said.
A full report on Oregon’s anticipated water needs in 2050 is undergoing final editing and will soon be made public, she said.
The department is also planning to address growing water demand by assisting with feasibility studies and other plans for water supply development, Lovellford said.