Today it was raining when I woke up, drove in heavy rain to work. By the airport I was driving in big water which was running down the street. The Las Vegas Valley was under cloudy skies almost all day long.
Flash flood season runs from July through September, and there we go here is the flashflood just 6 weeks after the heavy snowstorm in Las Vegas’ and it is February now.
The Las Vegas Valley gets minimal rainfall, but when it occurs it comes sudden. The rain runs down fast from the surrounding mountains because the city lies in a lower elevation. So the Valley drains down the mountains toward the Colorado River System.
The other problem is that the eroded sediments disperse from the mountains that surround the Las Vegas valley in the form of alluvial fans. The alluvial fans around the valley are coated with Caliche, which is a sedimentary rock, a hardened deposit of calcium carbonate. The Caliche is almost impervious, so when there is rainfall in the valley, almost 100% of it is runoff.
The Strip a little bit after 3pm
So the city built a network of flash flood tunnels that stretch throughout the city. The Flamingo Wash comes from Red Rock Canyon (where we just hiked a couple of days ago) under Caesars palace and reappears in and behind the IP parking garage before it gets in the tunnel again to continue its journey towards Lake Las Vegas and Lake Mead which is part of the Colorado River system.
The flood behind the Imperial Palace:
Just an hour and half later. Like nothing happened. The sky is beautifully blue, the Strip almost dry...
