San Acacia, New Mexico

San Acacia, New Mexico
unincorporated community
San Acacia
Coordinates: 34°15′18″N 106°53′51″W / 34.25507°N 106.897371°WCoordinates: 34°15′18″N 106°53′51″W / 34.25507°N 106.897371°W
Country	United States
State	New Mexico
County	Socorro County
Time zone	Mountain (MST) (UTC-7)
• Summer (DST)	MDT (UTC-6)

San Acacia is a small unincorporated community in Socorro County, New Mexico, United States. It was once a prosperous railway town, but is now largely deserted. There is a nearby diversion dam on the Rio Grande, important in irrigation.

Location

The village lies on the Rio Grande in the Albuquerque Basin. The village is 22 miles (35 km) south of Bernardo and 14 miles (23 km) north of Socorro. It is off Interstate 25 at exit 163.^[1] It is near the southern boundary of the Sevilleta National Wildlife Refuge. San Acacia gives its name to the stretch of the Rio Grande that extends south to the Elephant Butte Reservoir.^[2] The nearby San Acacia Diversion Dam is used to transfer water from the river into irrigation channels. When the river is low, the Isleta Diversion Dam, further to the north, and the San Acacia dam can divert all water from the Rio Grande along a 177 kilometres (110 mi) stretch of the river.^[3]

Foundation and growth

The settlement of San Acacio was named by the Spanish after Saint Acacius, leader of the ten thousand martyrs of Mount Ararat, an early Christian saint who was crowned with thorns from the acacia tree.^[4] The hill to the east of the San Acacio cemetery was the location where, in 1855, John W. Garretson fixed the Initial Point for the Principal Meridian and the Base Line. This is the reference point for all topographic maps of the state of New Mexico.^[5]

San Acacio became important in 1878 when the Atchison, Topeka and Santa Fe Railway was built through Socorro County on its route along the Rio Grande to El Paso, Texas.^[1] It was incorrectly given the official name of San Acacia after the railway came through.^[6]

Flooding and decline

The Rio Grande has very variable volumes where it passes San Acacia. In April the volume may be a few hundred cubic feet per second, but with the spring runoff in May the volume may rise to almost 10,000 cubic feet (280 m³) per second. In the summer, most of the water comes from unpredictable flash floods carried into the river by ephemeral tributaries.^[7] The town lies a few miles south of the point where the Rio Puerco and Rio Salado converge with the Rio Grande. In August 1929 there were torrential rains in the watersheds of these rivers, causing flooding that extended from San Acacia to San Marcial. There was renewed flooding a months later, damaging the railway and destroying all the crops in the valley.^[8] Once a prosperous town, many of the buildings including the old church have been abandoned.^[1]

Dam

In 1906 the narrow gorge at San Acacia was being considered for a dam. If built to a height of 50 feet (15 m), the dam would be 1,200 feet (370 m) long, and would flood about 18 square miles (47 km²) to an average depth of 25 feet (7.6 m). The drawback was that the basalt that forms the walls of the gorge is a thin sheet resting on loose sand and gravel. It seemed unlikely that there would be solid rock near enough to the surface to form a foundation for the dam, and there would be considerable leakage through the gravels.^[9]

A diversion dam was built in 1934 for the Middle Rio Grande Conservancy District, and was rehabilitated by the United States Bureau of Reclamation in 1957 as part of the Middle Rio Grande Project. It is 17 feet (5.2 m) high and 700 feet (210 m) long, a concrete structure with 29 radial gates. The dam serves the Socorro Division, and has a diversion capacity of 283 cubic feet (8.0 m³) per second.^[10] A 2003 report noted that there had been silting upstream of the dam but the width of the downstream channels had decreased sharply since the diversion dam was built. The river has cut a deeper channel in its bed and now runs faster. This made it harder for fish to travel upstream. The report suggested that if eight Gradient Restoration Facilities were installed in the downstream reach, that should be enough to slow the water, allowing sediment to settle and making fish passage easier.^[11] A 2005 report considered removing the dam altogether. Again, it suggested emplacement of Gradient Restoration Facilities to control erosion as sediment above and below the dam returned to normal levels.^[12]

References

Citations

1. Harris 2003, p. 87.
2. San Acacia - MRGBI.
3. Finch & Tainter 1995, p. 165.
4. Carrillo & Steele 2007, p. 150.
5. Varney 1987, p. 83.
6. Carrillo & Steele 2007, p. 228.
7. Hem 1985, p. 46.
8. Harris 2003, p. 89-90.
9. Geological Survey (U.S.) 1906, p. 143.
10. San Acacia Diversion Dam.
11. Bauer 2003, p. 4.
12. Greimann 2005, p. 40.

Sources

• Bauer, Travis R. (June 2003). "San Acacia Diversion Dam: Fish Passage Study". U.S. Department of the Interior Bureau of Reclamation. Retrieved 2012-09-30.
• Carrillo, Charles M.; Steele, Thomas J. (2007). A Century of Retablos: The Janis and Dennis Lyon Collection of New Mexican Santos, 1780-1880. Hudson Hills. ISBN 978-1-55595-273-0. Retrieved 2012-09-30.
• Finch, Deborah M.; Tainter, Joseph A. (1995). Ecology, Diversity, and Sustainability of the Middle Rio Grande Basin. DIANE Publishing. ISBN 978-0-7881-3013-7. Retrieved 2012-09-28.
• Geological Survey (U.S.) (1906). Water-supply paper. U.S. Govt. Print. Off. Retrieved 2012-09-30.
• Greimann, Blair (August 2005). "Sediment Erosion Analysis of San Acacia Diversion Dam Removal Alternative – Final Report". U.S. Department of the Interior Bureau of Reclamation Technical Service Center. Retrieved 2012-09-30.
• Harris, Linda G. (2003-08-01). Ghost Towns Alive: Trips to New Mexico's Past. UNM Press. ISBN 978-0-8263-2908-0. Retrieved 2012-09-30.
• Hem, John David (1985). Study and interpretation of the chemical characteristics of natural water. Dept. of the Interior, U.S. Geological Survey. Retrieved 2012-09-30.
• "San Acacia Diversion Dam". U.S. Department of the Interior. Retrieved 2012-09-30.
• "San Acacia". The Middle Rio Grande Bosque Initiative. Retrieved 2012-09-30.
• Varney, Philip (1987-11-01). New Mexico's Best Ghost Towns: A Practical Guide. UNM Press. ISBN 978-0-8263-1010-1. Retrieved 2012-09-30.