Živković dr S, Građevinski rečnik:
Pad (Hyd.Eng) = Head (Ht.)


ALABAMA POWER Southern Company - Glossary:
head
The distance that water falls in passing through a hydraulic structure or device such as a hydroelectric plant. Gross head is the difference between the headwater and tailwater levels; net head is the gross head minus hydraulic losses such as friction incurred as water passes through the structure; and rated head is the head at which the full-gate discharge of a turbine will produce the rated capacity of the connected generator.
( http://www.alabamapower.com/hydro/glossary.asp )


„Orient Land Trust - Hydroelectric Information
...
The pipeline extended 3155 ft and dropped in elevation (head) 256 ft
...
This created a 1ľ mile long 12" diameter pipe with a flow of 850 gpm of water at a head of 540 ft.“
( http://www.olt.org/programs/hydroelc.htm )


„B.Bloch Electrical and Automation Consulting Engineers Ltd
Small-Hydro Electrical Power Plant
...
An irrigation system by a 70" inches diameter pipe and 50mt head producing up to 2200KW since 1985 according to surplus water availability.
...
At the entrance to this reservoir we have installed a 260KW water turbine utilizing the flow and the available gross head of 85 meters.
...
However one should bare in mind that a lower head requires a bigger flow and therefore a bigger and more expensive turbine, therefore a low-head system requires flows for more time of the year.
In contrast a very high head requires lower flow but a stronger pipe.“
( http://www.bbloch.co.il/eSmallHydroElectricalPowerPlant.htm )