NATICK — Living at the end of River Street, with the Charles River literally a stone’s throw away, residents here are aware of the danger of flooding.
At least three times since 2006, the Charles has crested and covered the land around several residences, and boats were the only way to reach them.
The river swelled again early Friday and reached the patio steps of several homes. It is expected to rise just a bit more through Saturday before receding.
The incessant rain since Thursday has swelled rivers in many sections of Massachusetts, from the Hoosic River near Williamstown to the Taunton River near Bridgewater. By midafternoon Friday, there were 21 rivers at near-flooding levels and 12 at minor flooding levels, including the Charles in Natick, Wellesley, and Needham, and the Sudbury River in Saxonville, said the National Weather Service.
“Of course, I’m worried, but at least the ducks are happy,” said Anastasia Karakasidou, an anthropology professor at Wellesley College, whose house sits at the end of River Street in Natick.
She watched a group of ducks ride the swift current late Thursday evening and then awoke Friday to the sound of her sump pump. A portion of her basement was covered with river water, and the chair and table in her back yard were half-submerged.
“It’s coming from the walls, you see,” she said, pointing to a dark corner of her basement. “I knew living here what to expect, so it is not a total surprise.”
She has lived on the street for about 18 months.
Chad Callahan, who in 2000 built a sprawling two-story home at the farthest end of River Street, did not sound worried. He had to take a canoe to his home in 2009, when the river water came within a foot of the floorboards, even though the house sits on special piers.
“It might come into the driveway a little bit,” Callahan said. “Already it reached my front yard. Don’t think it’s going to go beyond that.”
Natick police are monitoring the situation on River Street, said Lieutenant Brian Grassey. “I did receive the Homeland Security prompt, as well as [the Massachusetts Emergency Management Agency’s] prompt about flooding,” Grassey said, referring to flooding advisories from those two governmental agencies.
“We’re aware. I don’t think that Friday’s event, at this point is that serious, not any worse than we’ve anticipated.”
The National Weather Service issued a flood watch for areas across much of Eastern Massachusetts, but many of the rivers are receding. Forecasters said residents living in flood-prone areas and along river banks should stay alert.
In a span of 33 hours, roughly 1½ to 3 inches of rain fell in Massachusetts. Royalston and Holliston have seen the most rain, with 2.95 inches reported, followed by Hudson with 2.71 and Auburn with 2.7.
In April and May, 4.59 inches of rain fell, 2.64 inches less than normal. But June has made up for that, recording 7.39 inches of rain, 5.5 inches more than normal for the month. This year, there has been 21.6 inches of rainfall, 1.6 inches above normal.
Gusty northeast winds will pose problems for the east-
facing shoreline, which largely avoided flooding issues. The Weather Service issued a warning for high surf between 5 and 7 feet and dangerous rip currents through Friday evening, with waters made choppy due to the strong winds.
Flooding on the Charles in the Natick area is common, according to the Natick Department of Public Works, and there is no danger of any homes being swept away.
“We’re keeping our fingers crossed it doesn’t get worse, but we’re nervous,” said Bill Chenard, the department’s director. If things continue to escalate, Chenard said, the department is ready with sandbags and other assistance.
In Shrewsbury, the week’s heavy rains caused the sanitary sewer system near the old waste-water treatment plant to overflow Friday with storm water, according to the state Department of Environmental Protection. The overflow caused a manhole cover to be dislodged, and a combination of untreated sewage and stormwater was flowing into Hop Brook at a rate of up to 1 million gallons a day, the department said.
The brook also flows into Smith Pond and Thayer Pond, both in Northborough, and the department advised all residents to avoid contact with all three bodies of water through the weekend.Globe correspondents Haven Orecchio-Egresitz and Lauren Dezenski contributed. Brian Ballou can be reached at email@example.com.