No. The wattage is a maximum value. Throttling the output, for example, will
reduce the power draw.

I've never heard that. I thought pumps all ran full out regardless if the
valve was open all the way or closed? Please elaborate.

I don't have references handy, I'll look. I remember that for a centrifugal
pump the current draw is lowest when the output is closed, so the impeller just
spins in the water in the pump housing.