What is the mass of an acre foot of water?
From http://www.unitedwater.com/pdfs/measurem… [pdf] Water Equivalents Table 1 gallon = 0.13 cubic feet = 8.34 lbs. of water 1 acre-foot = 43,560 cubic feet = 325,861 gallons (an acre-foot covers 1 acre of land 1 foot deep) 325861*8.34 = 2717681 lbs (2.7 million) = 1235309.4 kg (1.24 million) From Google calculator: 1 233 481.84 liters At 1 l = 1kg we arrive at a slightly different figure, perhaps due to round-off error in some of the conversions.