USA: Monsoon storms, key to recharging groundwater, may become less common
By Matt Weiser
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The major cities of the Southwest – Phoenix, Tucson, Albuquerque, Las Vegas – currently get most of their freshwater from the Colorado River or its tributaries. That river, however, is experiencing its 19th straight drought year, suggesting a new permanent dry state is gripping the giant watershed.
As a result, groundwater recharge from monsoons could become a much more important water supply in the long term.
Summertime monsoon storms are a distinguishing feature of the desert Southwest, marked by lightning and dramatic cloudbursts that offer a brief respite from baking heat. New research, however, suggests these storms will become less frequent but more intense as the climate warms due to greenhouse gas emissions. This could make monsoon rainfall more difficult to capture for reuse.
“If we accept as a general paradigm that monsoon precipitation is getting less frequent but more intense, how do we design capturing systems to recharge groundwater?” says Christopher Castro, an associate professor of hydrology and atmospheric sciences at University of Arizona. “I don’t precisely know. But it needs to be addressed.”
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