Greeno:
The question is broad, but yes and not, yes if the hydro turbine is designed to operate at the generator RPM ( 1800 to 3600 RPM) and capable of producing the torque necessary to drive the generator under the maximum load.
No if any of the above parameters can not be fulfilled.
A better question would be, I have this water source with so many gallon/minute and a head of so many feet.
Can I use a generator of a gas engine operating at ( let's say 3600 and so many KW)-- what can I attain ?.
In other words, inform properly to get a real and practical answer.
Nando