Flowing Into Silence

The natural world has a lot to say, if we're willing to listen.

- By Pete McBride

Early on a spring Sunday in 2014, the white light and arid breeze of the Sonoran Desert ushered in a refreshing morning. Farm workers labored in nearby fields, harvesting produce and moving irrigation pipes, their schedules dictated by moisture and sun. It was a typical day, but then, at 8:04 a.m., something very atypical happened. A set of giant control wheels on the nearby Morelos Dam, unmoved for years, started screeching as they cranked open the crimson steel gates of the last major blockade on the Colorado River. As the rusty doors lifted, a titanic surge of greenish-brown water raced south, swirling and eddying down a riverbed that had sat parched and unused since the late 1990s. Thirsty tamarisk bushes and cedar grass choked the previously dry riverbed below.

This blast of water is called a pulse flow, used by hydrologists to mimic a natural flood. The massive 105,392-acre-foot release was planned to last eight weeks, followed by smaller pulses over the next five years to support the rejuvenation of natural vegetation. It was a gush of liquid gold representing what many believed to be unfathomable—an international partnership to bring the river delta back to life.

For six million years, the Colorado River flowed to the Sea of Cortez, creating the largest desert estuary in North America and providing sanctuary for some 300,000 migrating birds. That cycle, however, diminished starting in the 1960s and then stopped altogether in the late 1990s, as the growing demand for water across seven U.S. and two Mexican states surpassed the river’s overallocated supply. Today, the Colorado is a lifeline for 40 million people, supporting more than five million acres of farmland. But in the process, its famous delta has dried and muted.