People in the lower Snohomish River Basin were being strongly encouraged to evacuate their homes as officials worried that dikes and levees may not hold back flood waters.

The river at Snohomish was expected to crest at 33.5 feet by 4 p.m., a level that it hasn’t reached since record floods in 1990 and 1975. The river reached 33.15 feet about noon.

The Snohomish County Sheriff’s helicopter crew reported just before 3 p.m. that water was spilling over the levees in several locations along the Snohomish River, including several areas south of Harvey Airfield outside Snohomish.

If people are unable to get out of their homes because of rapid water they are being encouraged to call the county’s emergency operation center at 425-388-5060.

Emergency crews are once again advising people not to attempt to drive through standing water. Snohomish County sheriff’s deputies are warning drivers that if they drive around barricades and get stranded they will be fined $388.

The flooding and expected damager were expected to exceed records set in 1990, said Chris Badger, an emergency planner for Snohomish County’s Department of Emergency Management.

“Based on the forecast it is the most significant flooding on record in the last 50 years,” County Executive Aaron Reardon said earlier in the day.

Voluntary evacuations were underway on Ebey Island. Just before 2 p.m., sheriff’s deputies and search and rescue workers went door to door telling people they should leave.

Lauralee Henry and her family began packing their bags as soon as the order was given. However she said her family planned to wait it out as long as they could.

“This is part of living between two rivers,” she said.

Gerald Kloss, who has lived on the island for ten years, starting preparing to leave on Monday. When the evacuation order was given, he packed his important documents into his tan Ford pickup and left.

“The only thing I really regret is having to leave my animals,” said Kloss, who has four chickens.

Under the US 2 trestle, some Ebey Island residents worked with inmate work crews from Monroe to fill thousands of sandbags. About 400 bags were used to plug a gap in a dike about 200 yards north of the trestle, said US Army Corps of Engineer project manager Noel Gilbrough.

He expected work crews to remain at the site until early Wednesday morning after high tide.

Flooding forced about 320 people to spend the night in emergency shelters set up in Granite Falls, Stanwood and Monroe. More people are likely to be displaced as severe flooding is predicted along the Snohomish, where many homes are expected to be inundated.

On Monday alone, emergency crews in the county used 100,000 sandbags, Reardon said. At the same time, 150 people required rescue from swift waters. Of those rescued, 120 were pulled to safety by firefighters, 36 by deputies with the Snohomish County Sheriff’s Office and one by a U.S. Navy helicopter crew.

Emergency workers today were to begin assessing damage in the Stillaguamish River basin. They need to make sure the roads and bridges are safe enough for people to return home as the flood waters recede, Badger said.

Since Monday evening, Monroe firefighters had rescued 15 people who were stranded by flood waters, Fire District 3 spokeswoman Audrey Duncan said. Firefighters used boats and kayaks to reach people who were surrounded by water. Some couldn’t get out of their homes and others had attempted to drive through surrounding water but became stranded.

Some areas were too dangerous for firefighters to reach by boat. Helicopters from the Snohomish County Sheriff’s Office and the U.S. Coast Guard were used to rescue people, Duncan said.

Others, including Susan Dennis, who lives on the Lowell-Snohomish River Road fled on their own this morning as the waters rose.

The road between Snohomish and Lowell also is a dike, the only thing protecting neighborhood homes from the nearby rising water. Flood waters began lapping onto the road by late morning Tuesday.

Dennis, who moved to the area about a year ago from San Diego with her husband, Brad Dennis, said “This is a new experience for us. I’m just going to keep praying and hoping for the best. But as I say that I see the water rising.”

Many rivers have crested and appear to be receding but people are continuing to become stranded because of numerous road closures and standing water.

The flooding has caused major road closures, including U.S. 2 outside of Index. The highway was closed earlier today because of a major rock and mud slide about five miles east of Skykomish. Drivers are being asked to turn around at Baring. The highway is not expected to reopen today and drivers headed east of the Cascade Mountains are being advised to use I-90, Washington State Patrol trooper Kirk Rudeen said.