Most owners have flooded the forward bilges when refilling the watertank. It’s a bit of a design flaw as there is actually an overflow to the cavity of the companion way hatch and from there into the grey water bilge. Even if not clogged it cannot handle the volume of water coming from a garden hose.
I managed to do it twice already...
A pump may help but as others say you need to think about the watertight compartments. You could use the A/C drain of the saloon A/C as evacuation hose. The water would then end up in the grey water bilge.
Personally I’m thinking to put an alarm on the dipstick to signal overfilling. That would prevent the overflow in the first place.