Regardless of the distance from Giza to Taposiris Magna, this was a suggestion for the reason an aqueduct exists.
What I find interesting is that after so much time has elapsed, mankind has no certain idea why these things are were even constructed. Huge expenses in effort, energy, money and time spanning several generations and all we can do is look at them and wonder.
What I find interesting is that there are people who still insist, based on nothing at all, that the Pyramids were constructed for no known reason. They were constructed as tombs, and were used as tombs. Period.