The river follows a U-shaped course and is approximately of 440 kilometres long.
Water is extremely valuable in the area.
Water from the Rio Loa supports local populations and large-scale mining industries. Local agriculture as well as local aquatic and terrestrial ecosystems depend on the river for their survival. Water from the Rio Loa water is not suitable for a standard purifying process because of the high levels of dissolved arsenic and boron, both derived from natural sources. The chemical composition of the Rio Loa water depends of the lithologic features, tectonic structure and geodynamic environment of the region, as well as climate. Human activity also has an impact on the river.