Is this because in the older parts of Scripps, the children of the homeowners are growing out of school age ? If that is true, then other neighborhoods like Carmel Valley would have the same problem, wouldn’t they ?[/quote]
The difference between SR, on one hand, and Carmel Valley / Stonebridge, on the other, is that SR is part of a big school district. If SDUSD sees falling enrollment in SRHS and rising enrollment in City Heights, they may decide to bus excess students to SRHS. But they can’t bus them to Carmel Valley (unless CV’s school district approves such a large scale interdistrict transfer, and it surely won’t approve that – or else it will be the superintendent’s head on a platter).
Besides, CV and Stonebridge aren’t in real danger of falling enrollment any time soon, they are both desirable areas and there’s a lot of free land available. CV and Stonebridge can easily double their populations upon buildout. 4S Ranch can triple the population. Scripps Ranch is more constrained in that aspect.
The assumption that ocrenter seems to be making is that school-age population “south of the 8” will keep growing, or at least it will not decline as fast as Scripps Ranch. This seems to be a bit unjustified to me. San Diego is more or less completely built out, areas south of the 8 are already densely packed and hispanicized; even if we magically replace each white City Heights holdout retiree with a hispanic family, that’s not going to tilt the scale that much. On the other hand, white holdouts aren’t going to leave all at once, hispanic immigrants will eventually assimilate and go through demographic transition. The official SANDAG forecast is slow uniform growth of school-age population throughout the city.