Annual Water Volume from Flow Rate

Converts a steady flow in gpm to an annual volume, used to size evaporation, blowdown, and makeup water budgets.

$$V_{\text{annual}}=\dot{V}\times 60\frac{\text{min}}{\text{hr}}\times H$$

Variables

Symbol	Meaning	Unit
$V_{a}nnual$	Annual water volume	gallons
$\dot{V}$	Flow rate (evaporation, blowdown, or makeup)	gpm
H	Operating hours per year (8,760 for continuous)	hr/yr

Worked example

Evaporation of 12.75 gpm x 60 x 8,760 = 6.70 Mgal/yr. Blowdown of 3.19 gpm gives 1.68 Mgal/yr, for total makeup of 8.38 Mgal/yr.

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Part of The Blueprint of Water