The problem here is that according to Aufbau Principle before 3d orbital 4s subshell comes.After filling 3p orbital with electrons you have 4 electrons left,you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with same spin.
The distance between the tank and the upstairs tap is lesser than the distance between the tank and the downstairs tap so water comes out with more force in the downstairs tap than from the upstairs one.