The article presents a method to estimate how fast water soaks into the ground and how much runs off during rainstorms in the Powder River structural basin in Wyoming. By plotting rainfall intensity against storm duration on special paper, the researchers could separate rain events into ones that caused runoff and ones that didn't. They found that by ranking soils based on how easily water passes through them, they could predict runoff more accurately. The results showed that the estimated runoff was very close to the actual runoff measured in six different basins.