How do mountain streams from the Sierra Madre Occidental support farming in northwestern Mexico?

The Sierra Madre Occidental serves as a vital source of water for the arid regions of northwestern Mexico. By acting as a watershed, the mountain range provides the necessary runoff to sustain agricultural development in both the interior plateau and the Pacific coastal lowlands.1

In the plateau, mountain waters form oases that support farming along rivers such as the Conchos, Nazas, and Aguanaval. Meanwhile, on the western side of the range, several rivers flow toward the Gulf of California, including the Yaqui, Mayo, Fuerte, Sinaloa, and Culiacán rivers. These westward-flowing streams are essential to the region's economy; many have been dammed to create large-scale irrigation systems that water important farming districts in the coastal lowlands.12