Gila River, Major Colorado Tributary, No Longer Reliably Reaches Main Stem Due to Diversions
The Gila River, the largest tributary of the Colorado River, no longer consistently flows into the Colorado River near Yuma, Arizona. Historically, the Gila River was a year-round desert lifeline, supporting human societies for millennia, including the Hohokam people who developed extensive irrigation canals. The river, which originates in the Gila Wilderness of New Mexico and spans 649 miles, now runs dry for most of its lower half. This desiccation is a direct result of extensive damming and diversion projects. For instance, the Coolidge Dam, completed in 1928, and the Ashurst-Hayden Diversion Dam siphon off nearly all of the river's flow for agricultural use in areas like the Casa Grande Valley. Its primary tributary, the Salt River, is also heavily dammed to supply metropolitan Phoenix. Consequently, the Gila River's natural flow has drastically reduced from approximately 1,900 cubic feet per second to a mere trickle, only reconnecting with the Colorado River during significant flood events when excess...
