The sad fact of the serious shrinkage of Lake Mead leads to the
neutral fact of the growth of tributary and mainstem deltas that feed
into the lake. The Colorado River's delta is an obvious example, but I
have gone for the delta of Las Vegas Wash in this post. LVW is an
ephemeral drainage that has 'gone all perennial on us' as a persistent
conduit of treated wastewater and an intermittent conduit of copious
amounts of storm runoff from mall and casino parking lots (among other
impermeable surfaces)

Turns out that the delta and the lake are also repositories for trends
in pharmaceutical use and abuse in Las Vegas...which is a little
creepy, no?

For an intro to the drug story, see:
http://toxics.usgs.gov/regional/emc/mead_vegas.html

For more on the delta (and some cool sonar stuff):
http://pubs.usgs.gov/of/2001/of01-070/index.html