Mesilla Diversion Dam
The Mesilla Diversion Dam is located in the Rio Grande about upstream of El Paso, Texas, about to the south of Las Cruces, New Mexico. It diverts water from the river for irrigation in the lower Mesilla Valley. The dam is owned by the United States Bureau of Reclamation, which built it, and is operated by the Elephant Butte Irrigation District. Background. The first small canals in the Mesilla Valley were dug in 1841, and more canals were dug after 1848, when Mexico ceded the region to the United States. By 1897, there were five main canals , all north of Chamberino. In 1908, the Leasburg Diversion Dam was completed. Water flow was still unpredictable, with the river often drying up for several months. This changed with the closure of Elephant Butte Dam in 1915, which regulated the flow. The Mesilla Diversion Dam was completed in 1916. By this time, the canal system served all of the valley. Structure. The dam was built as part of the Rio Grande Project. The dam was completed in 1916, and the crest was raised by in 1940. The weir crest is above sea level. It consists of a low concrete weir  with radial gates, flanked by levees. The dam has a structural height of and a hydraulic height of . The weir crest length is . The west side spillway has nine radial gates, each . The east side spillway has four radial gates, each . The main spillway has a capacity of per second. Canals. The dam diverts water into the East Side Canal and West Side Canal, which provide irrigation water to of land in the lower Mesilla Valley. The East Side Canal is long, and has a capacity of . The West Side Canal is larger at long, and has a capacity of  . Near its end, the West Side Canal crosses underneath the Rio Grande via the Montoya Siphon. References. Citations Sources