How to Read the Mead
In 1936 the population of Las Vegas was approximately 7,000 people. This was the year the Hoover Dam first went into operation with the Lake Mead reservoir being created. The dam as well as generating hydroelectric power created a water source for parts of Nevada, Arizona, California, and Mexico.
Prior to the construction of the Hoover Dam bypass, a part of the Interstate system called I-11, State Highway 93 ran along the top of the structure. Still today, mostly from the west side of the dam, a white outer band around the shoreline of Lake Mead is clearly visible. The top of this white band indicates the historical high watermark of the reservoir.
I typically pass through the area - often twice yearly.
This band however is yet another image used and abused by climate alarmists. They claim that the band is a clear signal of a continued drought caused by anthropogenic climate change. Apparently, populations, like that of the greater Las Vegas area ballooning to over 2.8 million, and the 42 million visitors to the location every year, have nothing to do with the shrinkage of the lake. Or, for that matter, upriver at Lake Mead’s source, the Colorado River, the building of the Glen Canyon Dam that then formed Lake Powell. A significant portion of water is also used for crop irrigation all the way into California.
According to Lake Mead statistics outflow, which includes evaporation and delivery from the lake to four states “are generally in the range of 9.5 to 9.7 million acre-feet resulting in a net annual deficit of about 1.2 million acre-feet”.
The reservoir’s decline started in the year 2000 when more water than ever started to be drawn from the reservoir. During the preceding years of ‘climate change’ water levels were rising. Levels were near current values in the 1930s and 1950s.
So apparently, even though a water deficit is proven, and more water than ever is used, to the climate change alarmist, the white band continues to be a result of anthropogenic global warming.
The excessive rains now on the east coast are climate change, the droughts here are climate change, when the reverse comes, it’s climate change - always so easy to say, but certainly never proven.
The linked story from Dr. Roy Spener, a meteorologist, a principal research scientist at the University of Alabama in Huntsville, and the U.S. Science Team leader for the Advanced Microwave Scanning Radiometer adds more detail.