The #ColoradoRiver delta to benefit from the Minute 319 agreement between the US and Mexico

Jonathan Waterman paddling the ooze in the Colorado River Delta
Jonathan Waterman paddling the ooze in the Colorado River Delta

Here’s a report from Sandra Postel writing for the National Geographic. Click through and read the whole thing. Here’s an excerpt:

The Colorado Delta was once one of the planet’s great desert aquatic ecosystems, boasting 2 million acres of lush wetland habitat. For millions of years, it received a huge spring flood as the winter snows melted in the Rocky Mountains and the resulting flows coursed south. The flood waters spread across the delta before emptying into the upper Gulf of California.

That yearly flood cleansed the river channel and floodplain, recharged groundwater, aided the reproduction of native cottonwoods and willows, and sustained the overall delta ecosystem and its extraordinary bird and wildlife habitat. It also connected the Colorado River to the sea, where fisheries depend on the mixing of saltwater with fresh water for their spawning and rearing grounds…

The last time the delta enjoyed a significant influx of fresh water was in the late 1990s, a period of unusually high precipitation in the Colorado watershed that resulted in “surplus” water passing through the basin’s dams, across the international border, and on to the thirsty delta in northwestern Mexico…

Minute 319 calls for a flood pulse of 105,392 acre-feet (130 million cubic meters). The water will be released from Lake Mead at Hoover Dam, and then, mimicking the historic natural flood, will flow south to the delta.

Compared with the pre-dam spring flood of some 15 million acre-feet, this pulse appears paltry. But the delta scientists expect it to be sufficient to flood low terraces and backwaters, move channel sediments, recharge groundwater, and promote the germination of native cottonwoods and willows, which create prime habitat for birds…

To learn more, click here to see our National Geographic videos, blog posts and photo galleries of the Colorado Delta..

More Colorado River Basin coverage here and here.

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