Throughout history, achieving the unachievable has been the civil engineer’s task. An example of this pioneering spirit is Mesa Verde National Park’s four prehistoric reservoirs.
For years, the National Park Service identified Mesa Verde’s Far View Reservoir site — formerly known as Mummy Lake — as either an ancient amphitheater or an unprecedented and innovative public works project.
Inability to explain how the ancestral puebloans could engineer a water system capable of sustaining their society in such an arid environment meant that little credibility was given to the reservoir theory, until recently. The reservoirs have now been added to the American Society of Civil Engineers’ (ASCE) list of National Historic Civil Engineering Landmark (HCEL).
“The Mesa Verde Reservoirs embody the ingenuity honored by the Historic Civil Engineering Landmark program,” said Patricia Galloway, president, of ASCE. “Without so much as written language, the ancestral puebloans that populated the river-less mesa top conquered the impossible by creating a water system to sustain their domestic and agricultural needs. They are truly civil engineering pioneers.”
Morefield, the largest and oldest of the reservoirs, measures 200 ft. in diameter and rises 16 ft. above the valley floor. Despite being built with only the most rudimentary tools, the reservoir was operational for approximately 350 years. completed as early as 750 A.D., Morefield could have contained up to 120,000 gal. of water. Fifty years after its completion, the technology used to build Morefield was duplicated on an adjacent off-stream canyon bottom. The resulting reservoir, Box Elder, was operational for approximately 150 years.
The technology was again duplicated around 950 A.D., when ancestral puebloans living on the mesa tops created a water supply where, even by modern standards, it would seem impossible. The two reservoirs, Far View and Sagebrush, remained operational until around 1100 A.D., when a profound drought, which lead to the ultimate depopulation of the Mesa Verde area, struck.
Though the reservoirs ultimately succumbed to the region’s harsh elements, the knowledge gained from their construction and operation not only influenced the creation of other prehistoric systems in the area, but also the system of acequias discovered in the Rio Grande basin by Spanish explorers in the late 1500s.
Established in 1906, Mesa Verde National Park includes more than 4,000 known archeological sites, and is the first and only cultural park in the National Park System. Mesa Verde was designated a “World Cultural Heritage Property” by the United Nations Educational, Scientific and Cultural Organization (UNESCO) on Sept. 8, 1978.
The HCEL was created to recognize and encourage preservation of landmarks, as well as promote historical awareness of civil engineering both professionally and to the general public. The process by which sites are selected involves nomination by an ASCE section followed by an ASCE/HCEL committee review. Local, national and international landmark sites are eligible for nominations to HCEL status.
To be selected as a historic landmark, the site must be of historic civil engineering significance, structurally or technically unique, at least 50 years old, accessible to the public and approved for HCEL status by the owner of the structure.
For more information, visit www.asce.org/history/.