Ralston Dam

Ralston Dam
Country	United States
Location	Jefferson County, Colorado.
Coordinates	39°50′00″N 105°14′27″W
Status	Operational
Opening date	1937
Owner(s)	Denver Board Of Water Commissioners.
Operator(s)	Denver Board Of Water Commissioners
Dam and spillways
Impounds	Ralston Creek
Height	204 ft (62 m)
Length	1,170 ft (360 m)
Reservoir
Creates	Ralston Reservoir
Total capacity	15,900 acre⋅ft (19,600,000 m3)
Active capacity	13,200 acre⋅ft (16,300,000 m3)
Surface area	160 acres (65 ha)
Normal elevation	1,844 m (6,050 ft)

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 204 feet (62 m), and a length of 1,170 feet (360 m) at its crest. 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 160 acres (65 ha), has a maximum capacity of 15,900 acre-feet (19,600,000 m³), and a normal capacity of 13,200 acre-feet (16,300,000 m³).

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. 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. Cotter hopes the rerouting will be temporary while it cleans the contaminated mine using bioremediation.