I attended this school during third, fourth and fifth grades. I don't remember any water runoff issues, but I certainly wasn't looking. The school was up a long steep driveway, surrounded by a white cross-timbered fence. 500 students seems a bit much, however, for that location. But there were some large fields in the back, and they could use some of that and still have enough for a soccer field.
When I was in the school, we learned nothing about jihad. I don't recall it ever being mentioned. We did have to say prayers every day, though.
Of course, when I went there, it was called "Fairfax Christian School" and it wasn't an Islamic institution, but instead run by the very conservative Republican Robert Thorburn. It was also rare in that it was a for-profit private school. Thorburn sold the school to the Saudis for what he throught was a lot of money. Trouble was, the local zoning boards refused to allow him anywhere to build a new school, so they were located in church basements for a while. One of his relatives got arrested for cutting down a tree on his own property because the tree was a danger of falling on the house or something really weird like that.
The current campus doesn’t have the runoff situation that the expansion would cause. Since you went to school there, the Pope’s Head Road drainage situation has become worse, and no one is allowed to build anything in the catchment area or do anything that changes the drainage. Except, I suppose, the Saudi government.