If the equipment downstream of a CFG pump is prone to gradual choking (time scale of weeks rather than months or years) would it be possible to detect this situation by monitoring the current drawn by the pump?

There is no throttling valve or VFD on this particular pump. Pump has a capacity of 100 m3/hr. 3 Phase 440 V.

My thinking says as the pump discharge progressively chokes the power drawn and hence current ought to gradually fall.

Is this reasonable?

 

On a positive displacement pump, perhaps.
but on non-positive displacement pumps, heat and vibration are your best clues.

 

Unless it's not feasible for some reason, I'd go with either discharge pressure (if pump inlet pressure is constant) or differential pressure across the pump or across an orifice or venturi in the discharge line. Make sure to put any new restrictions on the discharge side of the pump so as not to cavitate the pump.