Gustave
Member
Beautiful view!
My purpose in asking about the cisterns being elevated and gravity flow was in consideration to the extent the well system pressure could be potentially reduced by relocating the upper cistern to the same elevation as that home.
If there ever should be a fire, I anticipate the fire dept will be unlikely to use a yard hydrant but will be more likely to use a 3-4" suction line to draw water from the cistern using a high volume pump to supply multiple 2.5" or larger lines. For rural properties where there are no fire hydrants, they will typically bring additional water in a tank truck.
The upper tank belongs to my neighbor. And his house is very near the tank, at roughly similar elevation, so I don't think he plans to move it.
Cal Fire requires a 4" line from the water tank to a type of hydrant (2-1/2" brass National Standard male thread) which must be located next to the driveway, more than 50 ft, but less than 150 ft from any structures. If the pressure at the hydrant is less than 20 psi it must be clearly labeled "draft".