On Thursday I used 'blog-quality research to come up with a 'blog-park' figure for how much water might be saved by Los Angeles plan to use millions of ping pong balls to cover the local reservoir to prevent evaporation. Using rough numbers from swimming pool evaporation, I came up with an estimate of 311 million gallons saved per year. Well, today I saw this from NBC News:
California has released millions of plastic water-saving 'shade balls' into their water reservoirs in an attempt to prevent evaporation as the state battles record-breaking drought. The effort is expected to save some 300 million gallons of water each year.
Assuming their number is accurate, I came up with a number that was off by less than 4% using nothing more than Google and 15 minutes of my time.