prevent city flooding. Galena's Congressman, Leo E. Allen, helped acquire funding for city floodgates which were added in 1951 to connect to the river levee system. Significant recorded floods include: 1828 – In Galena's first recorded flood, water was high enough to allow steamboats to travel on city streets. 1937 – A flood inundated Main Street with up to five feet of water, causing serious damage to downtown buildings. 1972 – A storm upstream caused the flood gates to be closed but the river flooded the sewage treatment plan and backed up sanitary and storm sewers. Sand bags were placed around storm manholes to keep water from flooding the downtown with 3 feet of water. 1993 – Almost eight feet of water threatened downtown Galena, but was stopped by the city's floodgates. Late spring season rainfall led the Mississippi and Galena Rivers to their highest recorded levels. 2010 – On July 22, eight inches of rainfall in one night caused the river to swell to twice its usual level. The flood gates were closed, protecting downtown, but many businesses and homes reported damages to basements and lower levels. Had the flood gates not been in place, it was estimated that six feet of water would have covered Main Street. Damages were estimated between $7–8 million. President Obama declared the county a federal disaster area on Aug. 19. 2011 – In a 12-hour period between July 27 and 28, Galena received between 10 and 15 inches of rain. The Galena River rose to more than twice its normal height and possibly its highest recorded level since the floodgates were erected. The Grant Park sign, built in the 19th century, was washed away and there were major damages to downtown businesses, the city's trail system and roads. Initial damage estimates were around $16 million. Demographics 2020 census As of the census of 2020, the population was 3,308. The population density was . There were 2,008 housing units at an average density of . The racial makeup of the city was 87.5% White, 0.8% Black or African American, 0.6% Asian, 0.5% Native American, 4.4% from other races, and 6.2% from two or more races. Ethnically, the population was 10.5% Hispanic or Latino of any race. 2010 census As of the census of 2010, there were 3,429 people, 1,632 households, and 896 families residing in the city. The population density was . There were