"Lowering sea level doesn't drain interior lakes — depression lakes are perched"
▸ SYMPTOM
Lowering the global sea level does not drain interior lakes in a priority-flood water pass. Dropping sea from 3.0 m → 1.0 m → 0.5 m leaves the interior "water webs" visually intact (only ~8% triangle reduction) — only the coastal rim moves. A per-basin min-depth gate barely helps because inter-mesa basins run deep.
▸ CAUSE
Depression lakes are perched — filled to their own spill surface, not the ocean's. A priority-flood water pass keys water to sea level only for sea-connected below-sea regions. Every enclosed basin fills to its own rim and doesn't care where the ocean sits. Real-hydrology "water level" intuition misleads here — each basin has its own waterline, independent of sea level.
▸ FIX
Two levers actually dry the interior:
-
Per-basin depth gate — raise the minimum basin depth required for a lake to form. This eliminates shallow perched lakes entirely. A high enough gate drains all interior water (~77% triangle reduction in one step) while leaving the coast untouched.
-
Interior land floor — in the height pass, raise island-core cells that dip below sea up onto land. This targets sea-connected "water webs" that are immune to the basin gate (they're connected to the ocean, not perched). Feather the floor with an island drown fraction (full in the core, zero across the shore band) so the closed-coast moat is preserved.
Bonus: drained basins re-open tree sites and expose more climbable cliff — the terrain becomes more navigable as it dries.
▸ WHY IT WORKS
The sea dial only controls the global ocean surface — perched lakes are topologically isolated basins whose water level is determined by their own spill elevation, not the global sea. The per-basin depth gate removes shallow basins entirely (the lake never forms), while the land floor raises terrain above sea in the island interior, eliminating the sea-connected below-sea valleys that show as "webs." Together they give precise control over world wetness without fighting the topological independence of perched basins.