Springbrook is a small city in central Jackson County, Iowa, United States. The population was 143 at the time of the 2020 census. Springbrook …Springbrook is a small city in central Jackson County, Iowa, United States. The population was 143 at the time of the 2020 census. Springbrook is located at 42°9′43″N 90°28′48″W / 42.16194°N 90.48000°W.