MONONA, Wis. -- With more rain expected in the coming hours, officials said that flooding is expected around Madison's largest lakes.

VIDEO: Watch The Report | SLIDESHOW: See Viewers' Flooding Photos (Vol. 6)

The ground is already saturated from nearly a week's worth of rain and further precipitation is expected to just run off. This increases the chance for flooding, and could spell trouble for some Dane County residents who have been dealing with flooding during the last week, WISC-TV reported.

One of the areas where Dane County officials said they're focusing their attention is Belle Isle in Monona. Many Belle Isle residents returned home from work on Thursday night to find water much higher than when they left in the morning. Many locals as well as volunteers have been sandbagging all afternoon while the water level keeps rising.

County officials said that Belle Isle is just one of the areas that they're concerned about.

Dane County Executive Kathleen Falk and other county officials on Thursday afternoon outlined the possible flooding threat and what residents can do.

Officials said that county land and water management has put weed cutters in the Yahara River below the main chain of lakes to try to get water moving faster. They've also completely opened up the Babcock Dam out of Waubesa. Both lakes Monona and Waubesa are at least 16 to 20 inches higher than they should be, they said.

Falk said that he expects more reports of damage to come in.

"Consequences of the rain don't immediately show up in a lot of ways that can cause harm and damage to people and property," Falk said. "So we anticipate more damage over the next couple days."

To keep the water out, Belle Isle residents kept sandbagging. They were joined by other area neighbors and the Monona Grove varsity boys soccer team, who filled sandbags and hauled them to shore.

Belle Isle resident Dave Lombardo said that he has lived in the area for more than 12 years and that only once before has he seen the water in his back yard and basement. He said that he has friends helping sandbag his and his neighbor's yards. The ominous forecast has him preparing for the worst, he said.

"This morning, it was out at the rocks so it wasn't in the yard at all," Lombardo said. "With all the rain, they're forecasting we're trying to get the sandbags in place."

Travis Meikle, a Monona Grove senior, said that school officials enlisted them to help.

"It was good," he said. "We got a call about 1 p.m. today and our game got canceled so our coach got a call from our principal that they needed some help and got the guys to help out."

Besides Belle Isle, officials said that portions of Oregon, Middleton and the Town of Dunn are also under threat from flooding.

Flooding Washes Out County Highway Y Bridge

Meanwhile, a bridge on County Highway Y near Mazomanie was washed out after Wednesday downpour. Dane County emergency management officials said the bridge is now closed.

Officials said that it's amazing no one got hurt in the incident.

The storm produced about 2 inches of rain in a half-hour, WISC-TV reported.

Getting Sandbag, Water Quality Info

For city of Madison residents needing sand and sandbags, authorities said that they will be available after 10 p.m. Wednesday at:

Hoboken Lift Station at 1800 Waunona Way
Spring Harbor Park at 5218 Lake Mendota Drive.
Warner Park Beach at 1201 Woodward Drive
Tenney Park Beach at 1330 Sherman Ave.

People can also contact the city of Madison Engineering Division at 608-266-4430 during regular business hours or 608-266-4665 after hours.

Officials with the Madison-Dane County Public Health Department said that residents that have private water wells that are near flooding should probably get it tested. Health official Dr. Thomas Schlenker said that flooding often contaminates wells.

He said that residents can boil the water at a hard boil for 1 minute to ensure the water is drinkable. The health department lab is also available to test the safety of the drinking water. For more information about testing, visit the department's Web site or call 608- 243-0357.