1 March 1997
50 percent of total daily domestic requirements =
675,000/2 = 337,500 gallons
Fire demand = (1,500 + 469/2) X 60 X 2
This item will be reduced by the amount of water available
during the period of fire demand under emergency conditions.
With the largest pipeline out of service, an emergency supply
of 400 gal/min is available. This item becomes
208,140 - (400 X 60 X 2) = 160,140 gallons
50 percent of required daily demand plus the fire demand minus the
amount of water available in 24 hours under
emergency conditions =
337,500 + 208,140 - (400 X 24 X 60) = -30,360 gallons
The first item governs, and storage of about 350,000 gallons should be provided. Storage should be
provided as elevated storage because water is delivered from the city under adequate pressure and
additional pumping would not be necessary.
e. Water mains.
Fire demand rate:
(1,500 + 469/2) = 1,735 gal/min
Maximum day demand:
469 X 2.5 = 1,173 gal/min
Mains must be of adequate size to convey the fire demand rate.