Aggressive groundwater regulation would slow subsidence — but conflicts with PH industrial development needs.
Sea walls and dykes (the Manila Bay reclamation projects include them) provide ~3m protection — beyond that, ineffective against storm surge.
Managed retreat — relocating coastal communities — is politically and economically devastating, especially for informal settlers.
Most likely future: partial retreat from low-lying areas, defended high-value zones (BGC, Makati CBD), and progressive abandonment of marginal coastal barangays through the 2050s and 2060s.