We need to start by breaking down a square mile to get to a common denominator. Let’s use feet.
There are 640 acres in a sq. mile and each acre contains 43,560 sq. ft. An acre-foot is 43,560 sq. ft. x 1 foot, so an acre foot is also 43,560 ft^3 (cubic feet).
Ten inches (10") can be written as 0.8333... foot (10" / 12").
I’m sure you can figure it out from here but I guess I feel like typing!
43,560 sq ft * 0.8333 = 36,300 cubic feet. 36,300 cu. ft. / 43,560 cu. ft. and we’re back to 0.8333, so: 0.8333 acre-feet per acre. Kinda redundant, eh?
0.8333 acre-feet/acre x 640 (640 acres in a mile) x 16.6 sq. miles = 8,853.33 acre-feet of water.
Remember, an acre-foot is 43,560 cu. ft, so 8,853.33 acre-feet * 43,560 cu. ft. = 385,651,200 cu. ft.. There are approximately 7.4805 gallons US per cubic foot. 7.4805 gallons/cu. ft. * 385,651,200 cu. ft. = 2,884,863,801.60 gallons.
To convert acre-feet to meters^3, multiply acre-feet by 1233.482 (
http://www.convert-me.com/en/convert/un ... ot.en.html), which is 10,920,427.31 m^3