Environmental Setting

Valencia County’s location in central New Mexico gives it tremendous diversity in landscape formation and ecosystems. The Rio Grande bosque, a near-continuous ribbon of riverine wetlands and cottonwood-willow vegetation, characterizes the middle Rio Grande river valley for a stretch of about 150 miles. Thirty miles of Rio Grande bosque are within the Valencia County boundaries. The historical presence of the bosque is attested to by mentions of stands of cottonwood groves associated with marshy and swampy lands in the earliest historical writings of the area. Today, the bosque retains some of the richest floodplain farmlands and the last known segments of pre-development biota and environments of all the rivers in the United States (Bauer, et al, 2003).

Average annual precipitation throughout the County is less than 10 inches. In the County seat of Los Lunas, elevation 4840 ft., the average annual precipitation is 9.09 inches. Average annual maximum temperature is 72.8 degree F. The average minimum temperature is 38.2 degrees F. Valencia County’s growing season length can extend to 219 days, from late March to early November, if temperatures remain above 24 degrees F (National Resources Conservation Service, USDA, WETS Station: Los Lunas, 2002).

Surface winds are influenced mainly by the County’s topography. Wind speeds average nearly 10 miles per hour for the year. As is typical for all of New Mexico late winter and spring bring the strongest winds with dust when the soils are exposed and dry. Evapotranspiration for the whole of the Middle Rio Grande Region is estimated to be 105 thousand acre-feet per year (kafpy) for irrigated agriculture and valley floor turf. Riparian evapotranspiration comprises 69 kafpy (MRGWA, 2003). The average evaporation from a Class A measuring pan is close to 95 inches (Pease, 1972). During the growing season evaporation is more than 75 inches.
To the east and west of the bosque green belt, the terrain in Valencia County rises in gradual mesa formations of soft alluvial and gravel deposits. The west mesas give way to expanses of high, dry grasslands and shrublands interspersed with volcanic ridges and basalt flows. The dry rangelands have been used over centuries for grazing, agriculture near the Rio Puerco and the San Juan rivers, and mining. Significant deposits of calcite and aragonite are mined in a travertine quarry west of Los Lunas near Mesa Lucero, and cut for the market near Belen in a high-end building stone operation. Only two other quarries in the United States extract stone of the same quality. The mesas west of the river have also provided light mineral extraction over time of a sub-economic nature.

Throughout the western portion of the County, the Rio Puerco has a dry bed nearly year round, though it was at one time the longest running tributary of the Rio Grande.
The mesas to the east of the Rio Grande stretch into rangelands extending to the Torrance County line. The transition zone from high desert to pinon-juniper takes place at the abrupt ascent of the fault-block Manzano Mountains.

Agricultural History
Continued Growth

References

Bauer, P.W., Condie, C.J., Lozinsky, R.P. and Price, L.G., 2003. Albuquerque A Guide to its Geology and Culture. New Mexico Bureau of Geology and Mineral Resources, Socorro, NM.

Middle Rio Grande Water Assembly (MRGWA), 2002.

Pease, D. S., 1972. Soil Survey of Valencia County, New Mexico Eastern Part.