PORTLAND, Ore. -- The sub-freezing temperatures in Portland have led to 10 water main breaks within three days, and nearly 50 in a week, a water bureau official said Monday morning.

Crews were working Monday morning to repair the latest rupture on Southwest Barbur Boulevard near Hamilton Street, where an 8-inch cast iron pipe from 1941 burst.

Drivers were warned to expect delays and stay alert in the area and use caution as traffic may suddenly slow or stop. Barbur Boulevard will likely be down to one southbound lane until 5 p.m. Monday.

"This is the 10th main break over this holiday weekend," said Portland Water Bureau spokeswoman Jaymee Cuti. "Our crews have responded to more than 45 main breaks since last Monday."

She said the water bureau considers this time of the year to be "main break season." Portland gets an average of about 200 main breaks per year.

"We are getting a high percentage of our 200 annual average in a short amount of time because of the freezing temperatures," Cuti said.

Portland should see one more day of below-freezing temperatures before heavy rains move in, causing flooding concerns.

Related: Winter Storm Watch issued ahead of Flood Watch