No, it is NOT normal. That is a vent hole, and water should not get that high. Water should drain out the drain holes near the lower rubber mount. What you are seeing can damage the powerhead. Check to see if the tube and o-rings are there that go between the water pump housing and exhaust housing (around the drive shaft). Also check for excessive wear of the water pump impeller and/or pump housing. Your English certainly is much better than my Italian.