The cost of maintaining a water reservoir is c(W)=80 square root w hundred dollars, where w is the depth of the water in the reservoir (in feet). The depth of the water changes with the monthly rainfall. When monthly rainfall is 8 inches per month, the depth of the water is increasing by 1.75 feet per month. How fast is the cost increasing when monthly rainfall is 8 inches and the depth of the water is 5 feet? (Answers are rounded to the nearest hundred dollar.)