PORTLAND, Ore. - Summer school in Portland starts on Tuesday and enrollment is up considerably.

Portland Public Schools report a 20 percent increase this year. A total of 3,000 students are registered, which is forcing the district to add more classes.

Why are so many kids going to summer school? Oregon's new graduation requirements are what's got them scrambling.

So the school district is adding more courses and for the first time, classes will not be confined to Benson High School. The increase in demand has caused the district to open Jefferson High School as well.

"We're definitely seeing a huge surge in enrollment and we're glad to accommodate all of them, but we're bursting at the seams," said David Wood, Summer Scholars Director.

In Clackamas County, summer school classes are already under way at Milwaukie High School.

Portland's classes begin on Tuesday. There is still time to register, although some courses, like math and science, are full. However, administrators said they would add more classes if needed to keep up with the demand.