Lake Mead going dry?

Lake Mead is the huge, man-made lake held back by the Hoover Dam. It holds water from the Colorado River watershed, an area shown to the left. The watersheds the lifeblood of many areas in the desert southwest, the main water source for drinking and irrigation for many citizens in many southwestern states--and not just the states next to Hoover Dam. California, Arizona, New Mexico, Colorado, Utah, Wyoming, and Nevada all use Colorado River water.

Unfortunately, Lake Mead's days of abundance may be numbered. It seems that the time when the southwestern population has boomed (over the last 100 years) has been a time of unusual "wetness" in the southwest. Normal climate is much, much drier according to climate and archaeological records. In fact, in the past, severe drought that lasted hundred of years were not uncommon. We know this by looking at tree rings in some of the very long-lived trees that can still be found on the Colorado Plateau or trees used in construction at ancient pueblos such as Chaco Canyon.

A new study takes a closer look at Lake Mead, its future, and the future of the water supply of the entire southwest. It's not easy reading. In an article that will soon appear in the peer-reviewed journal Water Resources Research, the author makes a startling claim:

...there's a 50 percent chance that the manmade lake, a reservoir created by Hoover Dam located on the Colorado River 30 miles southeast of Las Vegas, will be dry by 2021, or even sooner if climate changes continue as expected and water use is not curtailed.

Wow. Such a drying of the Colorado River supply would be devastating to not only agriculture in the region, but culture as a whole. People simply cannot live in areas without a reliable water supply, the aquifers in the region have limited water, so where will future water supplies come from?

This situation has been known and documented for at least 20 years simply by looking at the water availability records, but nobody has taken significant action. This doesn't really even have anything to do with the debate about whether or not human-induced global warming is occurring, this kind of climate shift seems common in the southwest. Droughts, and even severe droughts, are simply a fact of life in the southwest and hopefully the citizens affected by lowered water levels will start taking serious action to prepare.