Anyone heard of Sponge Cities? Sounds like a good concept to better manage water. Maybe Las Vegas could use a Sponge City, if it has further sponge needs.
Allow me to introduce my new concept of “Loofah Towns”. Hey, you scratch my back…
I’d like to see cities built out of stuff that greatly expands when wet.
Las Vegas is not sponge-worthy.
Las Vegas sponges on gamblers. 
You got to pay extra for that.