Two Mile Reservoir, Santa Fe River, intersection of Canyon & Cerro Gordo Roads, Santa Fe, Santa Fe County, NM

Documentation produced as part of the Southwestern Water Resources Project.
Significance: Two Mile Dam, constructed in Santa Fe, New Mexico in 1893, embodies the distinct characteristics of a tamped earth dam, through its design and construction techniques. These methods began in the 18th century and with some modifications are still being used today. The dam was designed to reduce interior hydrostatic pressure and was constructed using goats to puddle the earth. The engineered design incorporated methods, including seepage collars and variation of material, to reduce the amount of water inside the structure. Concrete seepage collars stop water from traveling along the tunnel underneath the dam (Drawing 2/1). Earthen material was varied to slow the movement of water through the dam. The upstream portion of the dam was constructed using small particle fill, such as silt and clay, and was packed to achieve high density and the downstream portion of the dam was constructed using larger fill, consisting of sand and gravel (Drawing 2/1). Earthen dams have a line of saturation that should exist in relative equilibrium (Drawing 5/6). Varying the material to create a relatively impervious upstream slope and a pervious downstream slope aids in protecting the dam from failure through saturation. Two Mile Dam is one of the largest embankment dams in New Mexico, was the largest dam constructed at the time, and was used for both irrigation and potable water supply. Montezuma Dam, an earthen dam near Las Vegas, New Mexico, constructed after Two Mile, was approximately 20-25 ft (6-7 m) high and retained water for ice skating and ice supply. The construction of Two Mile Reservoir was a large undertaking which created substantial water supply for the City of Santa Fe, gained national attention, and was a catalyst for the urbanization of Santa Fe.
Unprocessed Field note material exists for this structure: N673
Unprocessed Field note material exists for this structure: N1295
Survey number: HAER NM-5
Building/structure dates: 1893 Initial Construction
Building/structure dates: 1972 Subsequent Work
Building/structure dates: 1994 Demolished