Abbreviation for
Gallons Per Hour, a measurement of the volume of liquid flowing through an area or device.
Commonly used in reference to bilge pumps (5,000 GPH), garden hoses (1,000 GPH), and Niagara Falls (2,700,000,000 GPH).
Niagara Falls statistic from http://buffalo.about.com/citiestowns/midlanticus/buffalo/library/weekly/aa072798.htm?PM=456_2005
Garden hose statistic from www.townofelizabeth.org/newpage6.htm