Drawing Water [sansumbrella.com] looks like a generative painting, but in fact illustrates the relationship between where water falls and where it is consumed within the United States. It shows how water is channeled, pumped, and siphoned to locations far from where it fell to the ground, based on real water consumption and rainfall data.
Each blue line corresponds to a daily rainfall measurement, of which the length and location are determined by the amount of rainfall measured and where it fell, respectively. The end location and color of each line are determined by the influence of water consumption: the more water a city uses, the stronger its pull on the rainfall.
Via Flowing Data.