| Ralston Dam | |
| Coordinates: | 39.8333°N -105.2407°W |
| Location: | Jefferson County, Colorado. |
| Status: | Operational |
| Opening: | 1937 |
| Owner: | Denver Board Of Water Commissioners. |
| Operator: | Denver Board Of Water Commissioners |
| Dam Crosses: | Ralston Creek |
| Dam Height: | 204feet |
| Dam Length: | 1170feet |
| Res Name: | Ralston Reservoir |
| Res Capacity Total: | 15900acre feet |
| Res Capacity Active: | 13200acre feet |
| Res Surface: | 160acres |
| Res Elevation: | 1844m (6,050feet) |
Ralston Dam (National ID # CO00205) is a dam in Jefferson County, Colorado.
The earthen dam was constructed in 1937 by the Denver Board Of Water Commissioners, with a height of, and a length of at its crest.[1] It impounds Ralston Creek for municipal water supply for the city of Denver. The dam is owned and operated by the Denver Board Of Water Commissioners.
The reservoir it creates, Ralston Reservoir, has a normal water surface of, has a maximum capacity of, and a normal capacity of .[2]
In 2010 officials discovered that the defunct Schwartzwalder uranium mine was contaminating groundwater near the reservoir, threatening the Denver water supply with concentrations of uranium some 1000 times the human health standard.[3] The owners of the mine, Cotter Corp., rerouted the Ralston Creek around the mine site after uranium levels of between 40 and 50 parts per billion were discovered in the creek, greater than the 30 ppb federal drinking water standard.[4] Cotter hopes the rerouting will be temporary while it cleans the contaminated mine using bioremediation.[5]