South Valley Water Hardness & Quality Report (2026)

South Valley, New Mexico, an unincorporated community in Bernalillo County south of Albuquerque — a major south Albuquerque Rio Grande Valley community with a large Hispanic-American (primarily northern New Mexico and Mexican-American), Native American, and immigrant working-class population, the Isleta Pueblo adjacent to the community, and a major Rio Grande Valley agricultural and rural residential community in the south Albuquerque metro area — draws its municipal water supply from the Middle Rio Grande Basin alluvial aquifer via the ABCWUA. Water hardness in South Valley measures 428 mg/L — classified as extremely hard (one of the hardest in the contiguous US).

South Valley's extremely hard supply reflects the Bernalillo County Rio Grande rift basin's exceptional calcareous geology. The Middle Rio Grande Basin aquifer at South Valley–Bernalillo County draws from: Quaternary–Tertiary calcareous basin-fill alluvium (thick calcareous alluvial fan deposits from the Sandia Mountains Precambrian calcareous basement and the calcareous Jemez Mountains volcanic terrain); the Rio Grande alluvial aquifer recharged by the Colorado Plateau's extremely calcareous formations (the Permian Yeso Formation calcareous evaporite, Pennsylvanian Madera Group calcareous limestone, Jurassic Morrison Formation calcareous carbonate); and Tertiary calcareous volcanic tuffs. The accumulation of these calcareous formations in the Rio Grande rift produces the extreme 428 mg/L.

At 428 mg/L, South Valley residents face severe hard water challenges. Scale deposits form extremely rapidly — daily descaling is recommended for all water-using appliances and fixtures. ABCWUA consistently delivers water meeting all New Mexico NMED and EPA Safe Drinking Water Act requirements.