"They say this is a once every 1,000-year flood and we've had two of them in two years", Hogan said.
Locals posted on social media photos and video of the turbulent floodwaters and people trapped in buildings.
The National Weather Service issued a flash flood warning for the area Sunday evening, calling it an "extremely risky situation" and urging motorists not to attempt to navigate flooded roads.
In a tweet Sunday evening, Maryland Governor Larry Hogan warned the flooding was "moving towards central Maryland", and urged residents to "avoid travel". Heavy rain is expected to continue in the area through at least 6:15 p.m., the National Weather Service reported. Those seeking shelter can go to the Roger Carter Community Center at 3000 Milltowne Drive.
"Strong storms bringing heavy rain & potential for flash floods are now moving across central Maryland". "They can give the money to residents, but not to the business and property owners, and those are the people we're trying to help".
Hogan said he is heading to the scene.
"It looked like we were in the Titanic or 'The Poseidon Adventure, '" the bride's father told The Baltimore Sun.
He said the storm could drop 10 to 12 inches of rain total, before it finally ends between 7:30 p.m. and 8:30 p.m. The Federal Emergency Management Agency awarded the state $1,044,224 for flood-mitigation efforts in Ellicott City.
Howard County Fire and EMS said there were reports of building collapses in the area and a gas leak broke out, BGE said, causing an evacuation of the west end of Main Street.
The town experienced similar flooding two years ago.
In 2016, the small town's main street turned into a raging river, carrying away cars and other debris and forcing dramatic rescues of people trapped in the flood.
Howard County Executive Allan Kittleman said the damage sustained Sunday is worse than what the city saw in 2016. The Patapsco River, located southeast of Ellicott City, experienced a 17-foot-climb in water levels over those two hours. A county spokeswoman there said the fire department has received dozens of calls about cars stuck in high water and flooded basements.
A flash flood emergency was issued in Maryland's Howard County at 4:40 p.m.