How did stone channels help conserve water in the dry Southwest?

In the arid environment of the American Southwest, Indigenous peoples utilized stone structures to manage scarce water resources effectively. Specifically, the Ancestral Pueblo and other groups constructed low walls known as check dams.12

These stone channels and check dams served as critical tools for water conservation by slowing the flow of runoff from sporadic but heavy seasonal rains. By reducing the speed of this water, these structures helped divert the flow toward cultivated fields, allowing the soil to absorb moisture that would otherwise be lost to rapid drainage or erosion. This practice was essential for supporting agriculture in a region where precipitation was unpredictable and limited to only a few major rains each year.213