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

"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."


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!

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.

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.

while the issue isn't anywhere near extreme in Canada, many of the small brooks and streams I used to trout fish in and run in the spring are virtually gone, and of those still around many are no longer paddle-able or fishable, because too many people are drawing from them or impounding the water for their own use. A stream in my daughter's back yard has been dry for over 20 years because the region (like a county) decided to build a series of retention ponds, "flood control" ponds, and diversions that literally dried up every stream on her side of town, others are old mill ponds that have been abandoned for a century or more..
Those ponds still exist even though every one is no longer used for irrigation or drinking water, some of the dams have not been needed for almost 100 years, and have permanently changed the hydrology for the worse, with many wells having gone dry, and where the water table has dropped 10' or more causing extreme damage to the affected watersheds including altering it from upland forest ecology to savannah or grasslands, displacing both flora and fauna...