In this article (And video above), I solve a problem related to the surface water system hydrologic budget that falls under the environmental engineering & water resources section of the FE exam, similar to what you may encounter during the exam.
A 7-acre surface area pond is located within a 520-acre watershed. Assume that the infiltration and the seepage are negligible. There is no plant biota around the pond. The watershed received 3.20 in of rainfall for the last 30-day month. The pond elevation at the beginning of the month is 520.5 ft with respect to mean sea level (MSL). By the end of the 30-day month, the pond had risen to 522.2 ft, MSL. Average stream flows into and out the pond during the month are 0.522 cfs and 0.22 cfs respectively. The amount of evaporation (in) of water that take place from the surface of the pond during the month is most nearly: