FINDLAY, Ohio — Firefighters and a volunteer armada navigated boats through streets awash in waist-deep water today, plucking neighbors and pets from porches as flooding that has swamped the Upper Midwest and Plains settled in Ohio.

The water forced at least 500 people to flee their homes in several northern Ohio towns. Rising water forced authorities to move about 130 inmates at the county jail in Findlay to a regional prison.

Many neighborhood rescuers showed up with canoes and kayaks wanting to help during Findlay’s worst flooding in nearly 100 years. Three men in a fishing boat ferried a mother and her 2-week-old daughter along with the family dogs.

“That was the catch of the day,” the baby’s neighbor, Angel Sanchez, said.

Milk jugs, garbage bags, and soda cans floated in the murky water. Tom Woods took his 8-foot fishing boat to help float out friends stranded in the neighborhood.

“Once we got here, everybody asked us to rescue more people,” he said.

The Blanchard River was 7 feet above flood stage today at Findlay, the highest since a 1913 flood, and could rise another half-foot or more, the National Weather Service said.

The rain subsided by mid-afternoon, and the National Weather Service issued a heat advisory for much of the state, with temperatures expected to hit the upper 90s.

In Bucyrus, 40 miles to the southeast, nearly 9 inches of rain had fallen since Monday and at least 200 people were still out of their homes, the Crawford County Department of Emergency Management said.

“Reality is starting to set in about just how much damage there is in some of the flooded areas,” the director of the agency, Tim Flock, said.

Governor Strickland declared states of emergency in nine counties in northwest and north-central Ohio, including Crawford County and Findlay’s Hancock County.

The death toll from two storm systems — one that has spanned the Upper Midwest and another from remnants of Tropical Storm Erin in Texas, Oklahoma, and Missouri — reached 22 yesterday when searchers found the body of a man tangled in a tree near Lewiston, Minn.

Flooding also continued in northern Iowa as thunderstorms dumped more heavy rain across the already water-logged region today. Three subdivisions along the Des Moines River near Fort Dodge were evacuated, and crews used rocks and sandbags to shore up a levee that had begun to give way, officials said.

The river crested at 14 feet, four feet above flood stage, and began a slow fall by midafternoon to 13.2 feet, said Penny Clayton, a spokeswoman for the city. She warned of additional rain, though.

A care center was evacuated in Humboldt, Iowa, as water poured into the basement, but no one was hurt.

Thousands of homes were damaged in Wisconsin and Minnesota as the storm swept through. A preliminary survey by the American Red Cross in Minnesota identified about 4,200 affected homes, including 256 complete losses, 338 with major damage and 475 that are still inaccessible, the state’s director of homeland security and emergency management, Kris Eide, said.

Preliminary damage reports in Wisconsin indicate 30 homes and 25 businesses were destroyed. Another 731 homes and 32 businesses were damaged.

In Oklahoma, which recorded a gust of 82 mph and 11 inches of rain, some 300 homes and businesses were damaged in the Kingfisher area and in Caddo County in southwestern Oklahoma, officials said. According to the Oklahoma Climatological Survey, 2007 is so far the fourth-wettest on record in the state, with an average rainfall total of 31.96 inches, 8.42 inches above normal.