Ralston Dam

Ralston Dam
CountryUnited States
LocationJefferson County, Colorado.
Coordinates39°50′00″N 105°14′27″W / 39.83334°N 105.24071°W / 39.83334; -105.24071
StatusOperational
Opening date1937
Owner(s)Denver Board Of Water Commissioners.
Operator(s)Denver Board Of Water Commissioners
Dam and spillways
ImpoundsRalston Creek
Height204 ft (62 m)
Length1,170 ft (360 m)
Reservoir
CreatesRalston Reservoir
Total capacity15,900 acre⋅ft (19,600,000 m3)
Active capacity13,200 acre⋅ft (16,300,000 m3)
Surface area160 acres (65 ha)
Normal elevation1,844 m (6,050 ft)[1]

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.[2] 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).[3]

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.[4] 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.[5] Cotter hopes the rerouting will be temporary while it cleans the contaminated mine using bioremediation.[6]

References

  1. ^ U.S. Geological Survey Geographic Names Information System: Ralston Dam
  2. ^ "Archived copy". Archived from the original on 2016-03-06. Retrieved 2012-09-16.{{cite web}}: CS1 maint: archived copy as title (link)
  3. ^ "Ralston". Archived from the original on 2012-10-19. Retrieved 2012-09-16.
  4. ^ Finley, Bruce (16 April 2010). "Defunct uranium mine contaminating groundwater near reservoir". Denver Post. Retrieved 5 June 2015.
  5. ^ Finley, Bruce (6 March 2012). "Cotter rerouting tainted creek near leaking uranium mine". Denver Post. Retrieved 5 June 2015.
  6. ^ Finley, Bruce (22 March 2013). "Cotter to brew uranium cocktail to clean tainted mine west of Denver". Denver Post. Retrieved 5 June 2015.