One of the more stunning photo comparisons that I’ve come across is this one above which shows Folsom Lake, one of California’s Reservoir’s, before and after the drought.
The photos were posted on Reddit and Imgur, and the original may have come from NASA. The photo comparison is pretty stunning, and the lower lake levels even revealed the ruins of an old town that was submerged when the lake was constructed.
However, how much do these photos really say about our drought conditions? It’s hard to tell without a little context. Using data from the California Data Exchange Center, I created the graph which shows the lake levels and a comparison to historical levels.
Clearly the photos were taken at points during the year at which the difference in water levels was exaggerated by the normal yearly cycle. The January 16, 2014 photo was clearly exacerbated by the very dry November and December in 2013.
Another thing to consider is that Folsom is one of the smaller California reservoirs as measured by total capacity. Lake Shasta and Lake Oroville are both more than 4 times larger. So the Folsom Lake levels may not be the strongest indicator of the overall California drought situation.
There is no denying that there is a serious drought, but there is a lot more context to the situation than what is apparent in those two photos.