WHATCOM COUNTY, WA (MyBellinghamNow.com) – A major traffic diversion for drivers south of Bellingham has been postponed.

WSDOT said the temporary bypass road for southbound I-5 traffic has been rescheduled to 8 p.m. on Monday, June 15.

The two-lane bypass near Chuckanut Creek was originally scheduled to begin Thursday, June 11, but WSDOT said crews need more time to prepare.

The bypass will be in effect through September while crews rebuild the southbound lanes to install a new fish-passable culvert. During that time, the speed limit will temporarily reduce to 50 mph in the work area.

The temporary route uses part of Old Samish Road, which has been closed to through traffic since late April and isn’t expected to reopen until the end of the year.

Northbound traffic was also scheduled to shift to a temporary two-lane bypass on Monday, but the change will now be pushed back to a later date.