Millilitres (mL) would be the best metric measure for a cup of water.
gallons
Since water towers generally have a very large capacity, I would say that cubic meters might be the best bet. You can measure the total volumetric capacity of the water tower in cubic meters and then determine the volume of water that is currently in the water tower. However, an amount of water can also be measured in liters.
meters
centimetre.
themonether
Milliliters
Millilitres (mL) would be the best metric measure for a cup of water.
In liters
gallons
Since water towers generally have a very large capacity, I would say that cubic meters might be the best bet. You can measure the total volumetric capacity of the water tower in cubic meters and then determine the volume of water that is currently in the water tower. However, an amount of water can also be measured in liters.
gallons
mL, L, cm3, m3 are all SI units that can be used to measure the volume of water.
Cubic metres or litres.
The best unit of measure to use when measuring the amount of water in a drinking glass is ounces. A liquid measuring cup can be used to measure the ounces of water.
Liquid ounces.