Water Conversion Tables Conversion between various units of measurement is often necessary for understanding requirements and needs of a water system or complying with regulations. Below is a chart for conversion of various common water volume and flow values 1 cfs = 646,300 gallons per day (gpd) 449 gallons per minute (gpm) 1 cfs for 24 hrs = 1.983 acre feet 1 cfs for 30 days = 59.5 acre feet 1 cfs for 1 year = 724.0 acre feet 1 gpm = 1,440 gallons per day (gpd) 0.0022 cubic feet per second (cfs) 1 acre foot = 0.504 cubic feet per second per day (cfs/day) 0.326 million gallons 43,560 cubic feet 325,900 gallons 1 cubic foot of water = 7.48 gallons 62.4 pounds of water 1 million gallons = 3.07 acre feet (a/f) Units: cfs: cubic feet per second (also CFS, c.f.s.) gpd: gallons per day (also GPD or g/d) gpm: gallons per minute (also GPM)     Member of: Boulder GNC Water Well's Internet Privacy Policy. © 2004 - Boulder Water Well Service and Supply Inc. Site maintained by Jason G. Fegel. new 01/29/03, updated 07/01/04