Water in the Valleys of the Sonoran Desert
In the Sonoran Desert, life waxes and wanes in accordance with precipitation. Annual rainfall can be 2 inches one year and 25 inches the next. Precipitation comes in extremes even in the highest elevations of the park. At 8,666 feet (2,641 m) in the Rincon Mountain District of Saguaro, Mica Mountain receives over 30 inches of rainfall annually. Good years of rain see explosions in plant and animal populations, while drier years usually result in dieoff. The Rincon Mountain District of the park averges roughly 12 inches of rainfall per year, and the Tucson Mountain District averages slightly less. Water is present year-round in the Rincon Mountain District with deep tinajas and springs, whereas the Tucson Mountain District may only have water for days at a time. Water infiltrates at a higher rate with increased vegetation, taking decades to surface in lower elevation springs from the high country. Monsoon storms often run off with extreme amounts of rain in short periods, making for a dangerous hiking scenario in canyons. Winter rains and snow are far more beneficial, leaving the soil moist for weeks or months. Unfortunately, climate change is drastically reducing snow and rain during the winter, putting in danger plants that depend on those rains when compared to monsoon activity.
Fire Impacts on Hydrology
Intense fire can completely alter or even destroy riparian ecosystems in fragile environments such as the Rincon Mountain District of Saguaro National Park. Perennial tanajas, from 5 feet to as many as 30 feet deep line the waterways here, providing life for lowland leopard frogs, canyon tree frogs and countless other species while providing year-round water for terrestrial animals as well.
See Landscape of Desert Waters to learn more about park waters.
This special booklet, supported by the Friends of Saguaro National Park, may take a few minutes to download, but is a great introduction to our water resources.
Last updated: October 24, 2023