Lake Lanier = 38,000 acres at full pool (From Wikipedia)

1 acre = 43,560 square feet

1 square foot = 144 square inches

Multiplying 38,000x 43,560×144 = 238,360,320,000 square inches

Evaporation varies by temperature, relative humidity, water temperature, wind, and sunlight.

ASSUMING that 1/4” evaporated yesterday:

59,590,080,000 cubic inches floated away in the air.

1 cubic foot = 1,728 cubic inches

Translating to cubic feet,

34,485,000 cubic feet evaporated yesterday

1 cubic foot = 7.48051948 US Gallons

257,965,714 Gallons evaporated yesterday

It reads 258 MILLION Gallons blowing away in the wind.

1 day = 24 hours = 1440 minutes = 86,400 seconds

34,485,000 cubic feet /86,400 seconds=

399 CFS evaporated yesterday !!!!!!!!!!!!!

 

For perspective on August 13, 2009:

Upper Chattahoochee at Cornielia gauge shows 300 CFS.

Chestatee at Dahlonega gauge shows 100 CFS.

This means that virtually all the water from the Chattahoochee and Chestatee evaporated.