Approximate Conversions

Flowrate

1 MGD = 1.547 cfs
1 MGD = 694 gpm

100 MGD = 154.7 cfs
65 MGD = 100 cfs

1 cfs = 448.8 GPM
2.228 cfs = 1000 GPM
1 cumec = 35.315 cfs

Volume

1 cu ft = 7.48 Gal
1 m3 = 264.2 Gal
1 cu ft = 28.32 Litre
1 MG = 37 acre-inch
32.6 MG = 100 acre-ft
1 acre-inch = 27152 Gal
1 acre-inch = 36.3 x 10 x 10 cu ft
1000 acre-inch = 27.15 MGal

Length

100 m = 328 ft
100 m = 3937 inch
1 mi = 5280 ft = 1609.34 m
1 international foot = 0.3048 m (exact by definition)
1 U.S. Survey foot = 1200/3937 m (by definition)

Area

1 Acre = 43560 sq ft
640 Acre = 1 sq. mi
1 ha = 107636.76 sq ft
1 ha = 2.471 Acre

Pump

Horsepower ≅ ft x cfs/ η / 8.834
$/yr ≅ 66.6 x HP x ¢/kWh

Pressure

10 m water = 1 kg-force / sq. cm
10 m water = 14.22 psi
100 ft water = 43 psi
1013.25 millibar = 101.325 kPa = 760 mm Hg = 29.92 inches Hg = 14.70 psi
1 millibarbar drop atmoshpheric pressure raises the tide by 1 cm
Only for approximate conversions

Pipe Diameter Formula

ft = [ Q/35.63√s ] (3/8)
flow
slope
Diameter Inch

Pipe diameter?

Orifice - Pipe Equivalency Formula

Orifice  :: Pipe
C2 Dia4 = 32 Dia(16/3)/ Length