Seems some never learn!
https://en.wikipedia.org/wiki/Ellicott_City,_MarylandFloods
The town is prone to flooding from the Patapsco River and its tributary the Tiber River. These floods have had a major impact on the history of the town, often destroying important businesses and killing many. Ellicott City has had major devastating floods in 1817, 1837, 1868,[5] 1901, 1917, 1923, 1938, 1942, 1952, 1956, 1972 (Hurricane Agnes), 1975 (Hurricane Eloise), 1989, 2011, 2016, and 2018. The 1868 flood washed away 14 houses, killing 39 to 43 (accounts vary) in and around Ellicott City. It wiped out the Granite Manufacturing Cotton Mill, Charles A. Gambrill's Patapsco Mill, John Lee Carroll's mill buildings, and dozens of homes.[5] One mill was rebuilt by Charles Gambrill, which remained in operation until a fire in 1916.[6]:36
Historic flood stages marked on the B&O viaduct, c. 2006. Hurricane Agnes flood stage (14.5 feet (4.4 m)) is in the middle of the photograph.
A 1923 flood topped bridges, in 1952 an 8-foot (2.4 m) wall of water swept the shops of Ellicott City, and a 1956 flood inflicted heavy damage at the Bartigis Brothers plant. On June 21, 1972, the Patapsco River valley flooded 14.5 feet (4.4 m) from the remnants of Hurricane Agnes, taking out a concrete bridge, destroying the Jonathan Ellicott home, and the 1910 Victor Blode water filtration plant, and flooding Main Street to the Odd Fellows hall.[6]:26 The Old Main Line of the B&O Railroad also sustained serious damage.
On September 27, 1975, the town was flooded 9.0 feet (2.7 m) from Hurricane Eloise. Floods also occurred September 22, 1989, from Hurricane Hugo, and on September 7, 2011, flooding 11.0 feet (3.4 m) from Tropical Storm Lee.
On July 30, 2016, a storm dropped 6 inches (150 mm) of rain in two hours on the community. The resulting flash flood caused severe damage in historic Ellicott City, especially along Main Street.[7] Many homes, roads, businesses, sidewalks, and more were destroyed by the flooding, including the town's landmark clock.[8] A state of emergency was declared, and two people died as a result of the flooding.[9][10]
2018 flood
Main article: 2018 Maryland flood
On the afternoon of May 27, 2018 after receiving over eight inches of rain in the span of two hours, historic Main Street flooded[11] again days before the new flood emergency alert system was to become operational.[12]