Germantown Dam is an earthen embankment located across Twin Creek in southwestern Montgomery County near the Village of Germantown. Conservancy Road goes across the top of the dam. Construction of the dam began in March of 1918 and was completed in November of 1920.
The dam has two concrete conduits through the base of the embankment at the left (north) abutment. The conduits are sized to discharge floodwater at a rate that can be handled by the flood protection levees and channels downstream. The remainder of the floodwaters are temporarily stored behind the dam and released over time. An emergency spillway is located in a low area through the left abutment north of the dam. It would take eight days to empty the storage basin after a maximum high-water event. Germantown Dam can store 34.55 billion gallons of floodwater.
Learn more: How do dry dams work? | 1913 Flood History
Elevation and Hydraulic Information
Ten Highest Storage Events, 1922-2023
| Date | Elevation (ft. above sea level) | Depth (ft.) | Storage (percent) |
| Capacity | 814.2 | 91.0 | 100.0 |
| 01/22/1959 | 786.4 | 63.2 | 31.8 |
| 02/26/1929 | 777.7 | 54.5 | 20.8 |
| 01/27/1952 | 776.7 | 53.5 | 19.8 |
| 01/06/2005 | 776.4 | 53.2 | 19.6 |
| 03/05/1963 | 776.0 | 52.8 | 18.5 |
| 12/22/2013 | 775.9 | 52.7 | 18.4 |
| 04/04/2018 | 775.3 | 52.1 | 17.8 |
| 01/15/1937 | 775.0 | 51.8 | 17.5 |
| 01/22/1937 | 773.2 | 50.0 | 15.9 |
| 01/05/1949 | 772.5 | 49.3 | 15.3 |
Germantown MetroPark
Chief Engineer Arthur Morgan felt strongly that the lands surrounding the dry dams (when not actively storing floodwaters) should be available to the public for outdoor recreation use. The land that is utilized for the flood protection system also provides unparalleled public access to the Great Miami River and its tributaries. More than 20 public jurisdictions in five counties hold permits to operate parks, trails and related attractions on Miami Conservancy District land. Five Rivers MetroParks is the largest of these organizations, providing recreational opportunities on hundreds of acres of flood protection land in the Dayton region.
In 1967, Five Rivers MetroParks leased Germantown MetroPark from the Miami Conservancy District. Germantown MetroPark now is primarily managed for natural diversity, providing the Miami Valley with a variety of outdoor activities.
Directions to the Germantown Dam | River Access Points
