Charles Hatfield called himself a "moisture accelerator". In 1916, he offered to make rain fall and fill the reservoir for San Diego. Hatfield suceeded to such an extent that the city suffered the worst floods in its history, with dozens of deaths and damages in excess of $4 million!
On January 1, 1916, Hatfield arrived at Morena Dam, some 60 miles east of San Diego, and set to work. First he erected a wooden tower about 20 feet high. On to of it he placed large galvanizing trays containing his special moisture attracting mixture. Then, through a process of chemical evaporation – the details of which he kept a closely guarded secret – he began “coaxing, wheedling, and courting” nature.
http://socyberty.com/history/hatfield-the-rainmaker-the-man-who-courted-nature/
From the Upcoming ueue, submitted by MrGhaz.
Wide awake in San Diego
Smallest root shrinking dry
The fish are swimming closer inside Lake Morena
Still get no rain from the sky
Neat!
http://www.fccc.org.br/en/
It is so effective that City Administrations (Rio, São Paulo), and private organizations pays then a not-so-large fee to prevent raining during public events (open-air concerts, New Year's Eve...)
That is one heck of a story, BTW.