diff --git a/engine/src/entities/improvement.gd b/engine/src/entities/improvement.gd
index 77defd61..f57254ca 100644
--- a/engine/src/entities/improvement.gd
+++ b/engine/src/entities/improvement.gd
@@ -11,98 +11,8 @@ extends RefCounted
 ##   terrain_change, mana}
 
 
-## Fallback improvement data when DataLoader has no entries loaded yet.
-## Must stay in sync with improvements.json schema.
-const FALLBACK_DATA: Dictionary = {
-	"farm": {
-		"build_turns": 5, "yields": {"food": 1},
-		"valid_terrain": ["grassland", "plains", "enchanted_forest"],
-		"effects": {},
-	},
-	"mine": {
-		"build_turns": 6, "yields": {"production": 2},
-		"valid_terrain": ["hills", "mountains"],
-		"effects": {},
-	},
-	"quarry": {
-		"build_turns": 7, "yields": {"production": 1},
-		"valid_terrain": ["hills"],
-		"effects": {},
-	},
-	"lumber_mill": {
-		"build_turns": 6, "yields": {"production": 1},
-		"valid_terrain": ["enchanted_forest"],
-		"effects": {},
-	},
-	"plantation": {
-		"build_turns": 5, "yields": {"gold": 1},
-		"valid_terrain": ["grassland", "enchanted_forest"],
-		"effects": {},
-	},
-	"pasture": {
-		"build_turns": 5, "yields": {"food": 1, "production": 1},
-		"valid_terrain": ["grassland"],
-		"effects": {},
-	},
-	"trading_post": {
-		"build_turns": 5, "yields": {"gold": 1},
-		"valid_terrain": "any_land",
-		"effects": {},
-	},
-	"road": {
-		"build_turns": 3, "yields": {},
-		"valid_terrain": "any_land",
-		"effects": {"movement_cost_modifier": -1},
-	},
-	"fort": {
-		"build_turns": 8, "yields": {},
-		"valid_terrain": "any_land",
-		"effects": {"defense_bonus": 50},
-	},
-	"mana_well": {
-		"build_turns": 10, "yields": {},
-		"valid_terrain": ["mana_node"],
-		"effects": {"mana": 1},
-	},
-	"irrigation": {
-		"build_turns": 5, "yields": {},
-		"valid_terrain": "any_land",
-		"effects": {"moisture_delta": 0.05},
-	},
-	"drainage": {
-		"build_turns": 5, "yields": {},
-		"valid_terrain": ["swamp", "grassland"],
-		"effects": {"moisture_delta": -0.05},
-	},
-	"windbreak": {
-		"build_turns": 5, "yields": {},
-		"valid_terrain": "any_land",
-		"effects": {"wind_speed_multiplier": 0.5},
-	},
-	"terrace_farming": {
-		"build_turns": 8, "yields": {"food": 1},
-		"valid_terrain": ["hills"],
-		"effects": {"prevents_erosion": true},
-	},
-	"deforestation": {
-		"build_turns": 3, "yields": {},
-		"valid_terrain": ["enchanted_forest"],
-		"effects": {"terrain_change": "grassland"},
-	},
-	"reforestation": {
-		"build_turns": 10, "yields": {},
-		"valid_terrain": ["grassland", "desert", "tundra"],
-		"effects": {"terrain_change": "enchanted_forest"},
-	},
-}
-
-
 static func _get_data(improvement_type: String) -> Dictionary:
-	## Try DataLoader first, fall back to built-in constants.
-	var data: Dictionary = DataLoader.get_improvement(improvement_type)
-	if not data.is_empty():
-		return data
-	return FALLBACK_DATA.get(improvement_type, {})
+	return DataLoader.get_improvement(improvement_type)
 
 
 static func can_build(improvement_type: String, biome_id: String) -> bool:
@@ -115,7 +25,7 @@ static func can_build(improvement_type: String, biome_id: String) -> bool:
 
 	# "any_land" allows any non-water terrain
 	if valid is String and valid == "any_land":
-		return biome_id != "ocean"
+		return not BiomeRegistry.has_tag(biome_id, "is_water")
 
 	if valid is Array:
 		return biome_id in valid
@@ -194,6 +104,7 @@ static func prevents_erosion(improvement_type: String) -> bool:
 static func get_all_types() -> Array[String]:
 	## Return all known improvement type IDs.
 	var types: Array[String] = []
-	for key: String in FALLBACK_DATA:
-		types.append(key)
+	for entry: Dictionary in DataLoader.get_all_improvements():
+		if entry.has("id"):
+			types.append(entry["id"])
 	return types