We put in a rain barrel this year. I figure it alone has ended the drought in Oklahoma.
We are several inches above the total yearly average rainfall already. Our drought is 100% over and all the lakes are FULL and everything is GREEN.
The rain barrel is neat in that it will fill up with just a small rain and my wife can water the plants in the back yard easily. We have had so much rain (NO COMPLAINTS) that she has not used it much.