U.S. Rivers that No Longer Reach the Ocean, and Why Lakes Mead and Powell are Drying Up

[Glenn MacGrady]

"A river reaching the sea is the assumption built into the word river, and across the American West it is increasingly not true. The Colorado has not made the Gulf of California under natural conditions since 1998. The Gila, once one of the great tributaries of the Southwest, runs dry through metropolitan Phoenix for most of the year. Sixty miles of the San Joaquin simply vanished from the map for six decades. In every case the water did not evaporate or get stolen by drought alone, it was allocated, and in most cases allocated to more users than the river physically contains. Here are the American rivers that stop short, and what happens at the end of each one."

The American Rivers That No Longer Reach The Ocean

The Colorado has not reached the sea naturally since 1998. The Gila, Santa Cruz, San Joaquin and Owens all stop short too. The American rivers that no longer finish.

www.worldatlas.com

While the West has been in drought for several years, the primary reason Lake Mead and Lake Powell, the two largest reservoirs in the U.S., have declined to record low levels is because of historic over-allocation of the water of the Colorado River.

The Colorado River Compact of 1922 allocated 17.5 million acre feet ("maf") of water annually among seven states . . . in perpetuity. This allocation, unfortunately, was based on an anomalous "Wet Period." The negotiators looked at hydrologic data from the previous 20 years (roughly 1902–1921). Unbeknownst to them, this was one of the wettest periods in the Colorado River's 1,200-year recorded history. They assumed the river's average annual flow was well over 16 to 17 maf. In reality, the long-term historical average is closer to 13–14 maf, and drought has recently shrunk that to about 12 maf. Meanwhile, the population served by the water allocation has grown from 1-2 million people in 1922 to over 40 million today.

Methinks this water problem is mathematically insoluble for the Southwest USA.

Go East, young man, go East!

 

[ppine]

Over allocation is a common problem in the West.
Nevada gets 10% of the annual allocation or about 300,000 acre feet or less depending on the year.
That is 90% of the supply for Las Vegas.
Agriculture uses the vast majority of the water in the Colorado River System
Desal plants on the coast of California may be the only real solution to the problem.
Irrigation efficiency would help alleviate water shortages in the Colorado Basin, but water law requires ag users to use their water rights or lose them.

 

[Steve in Idaho]

Add to that list the Snake River and Lost River in Idaho...sort of. The Lost River never did make it to the sea. It made it to the historical lava beds in the Snake River plain and entirely dissapeared there into the aquifer at or before the Lost River Sinks - hence, the name. It wasn't actually lost though because it charged the aquifer that also feeds the Snake River. Now with all the diversions for agriculture, it rarely ever makes it all the way to The Sinks. In the last forty years, I have seen water flowing in the channel near Arco exactly once, about IIRC eight years ago.
The Snake itself has been sucked dry by water users most years to the point of literally just a trickle below the Milner dam. If it wasn't for the aquifer recharging to the tune of 5200 cfs (which is about 2,000 cfs lower than historical estimates before groundwater use for irrigation became common) the stretch between there and at least as far as Malad gorge would probably be essentially dry most of the year.