SAGINAW, MI -- With the Tittabawasee River expected to reach flood levels topped only once since recording began, state and local officials are mobilizing resources and watching how the next 24 hours play out.

The worst of the flooding is predicted around 8 a.m. Saturday, June 24, when the river crests at 31.5 feet -- a flood level surpassed only by the historic high of 33.89 feet recorded on Sept. 13, 1986, according to the National Oceanic and Atmospheric Administration.

"If you're from the Midland area, you remember the flood of '86," said Selina Tisdale, community affairs coordinator for the city of Midland. "This very easily could be one of the biggest overland flooding events of our community."

Friday morning, as rain continued to pour and add to the accumulation from overnight, Michigan State Police announced activation of the State Emergency Operations Center for Isabella and Midland counties, which were hard hit with road flooding and washouts.

The activation readies state resources should Gov. Rick Snyder declare a state of emergency, said Capt. Chris Kelenske, deputy state director of Emergency Management and Homeland Security, Michigan State Police.

State resources normally in the area, such as Department of Natural resources riverboats and police helicopters, will be available if needed, Kelenske said.

But so far, the preparations for possible flooding was handled by the counties and municipalities, he said.

In Midland, workers were filling the parking lots near flood vulnerable areas with gravel and sand to help absorb excess waters once the Tittabawasee River rises, Tisdale said.

Tisdale said those are the bulk of the precautionary efforts.

"That's really all we can do," she said. "Now it's in Mother Nature's hands."

The American Red Cross, in cooperation with the chapters located in Isabella and Midland counties, will be opening an evacuation center at Lee Township hall, 1485 West Olson Road in Midland, and will also be opening a shelter at the West Midland Family Center, 4011 W. Isabella Road in Shepherd.

Members of the public needing the Red Cross assistance should contact Listening Ear by calling 211.

Throughout the day, emergency responders were called to roughly a dozen drivers stranded in their vehicles in high waters, Tisdale said.

In all, about a couple hundred homeowners called the city or emergency center to report their storm sewers backing up, she said. No businesses have reported damage yet, she added.

The exact extent of damage to homeowners and store owners won't be known until later.

Saginaw County Sheriff's Office Lt. Mark Przybylski, who is director of the county's Emergency Management and Homeland Security, said they were monitoring the situation at this time, as the county is downstream of Midland.

In Isabella County, the Chippewa River south of Mount Pleasant began rising rapidly throughout Friday morning and is also expected to hit its historical second-highest flood level, according to NOAA.

At 8 p.m. Friday, the waters are expected to reach a major flood level of 13.5 feet -- just 2 feet below the highest crest recorded on Sept. 12, 1986.

Isabella County Administrator Margaret McAvoy said the rain so far has caused numerous damages to private and public properties and has resulted in the barricading of more than 60 county roadways.

A damage assessment is being compiled with help from Michigan State Police, who are providing an eye in the sky with a helicopter and drone, McAvoy said.

"Isabella County Emergency Management, Sheriff's Office in cooperation will all our municipal partners, wishes to ensure our citizens that the public's safety is our first concern," McAvoy said. "Please help us by checking on your friends, family and neighbors to ensure their safety."

The Saginaw River near Old Town Saginaw is expected to reach moderate flooding levels of 20.5 feet around 8 a.m. Sunday, according to NOAA. The crest does not break the historical top 10 flood levels.

NOAA Meteorologist Jordan Dale said the rising river waters are from a combination of heavy rains overnight Thursday-Friday and rains from days before.

"The prior rainfall created a situation where the ground was already saturated so it had a difficult time absorbing the additional rainfall," Dale said.

Midland and Isabella counties received roughly 4 to 7 inches of rainfall overnight Thursday-Friday, he said.