diff --git a/api/__init__.py b/api/__init__.py
index 408e40e..611c91b 100644
--- a/api/__init__.py
+++ b/api/__init__.py
@@ -20,4 +20,13 @@ from .s1_title import set_title, get_title
 
 from .s2_junctions import add_junction, delete_junction
 from .s2_junctions import get_junction_elevation, get_junction_demand, get_junction_pattern, get_junction_coord
-from .s2_junctions import set_junction_elevation, set_junction_demand, set_junction_pattern, set_junction_coord
\ No newline at end of file
+from .s2_junctions import set_junction_elevation, set_junction_demand, set_junction_pattern, set_junction_coord
+
+from .s3_reservoirs import add_reservoir, delete_reservoir
+from .s3_reservoirs import get_reservoir_head, get_reservoir_pattern, get_reservoir_coord
+from .s3_reservoirs import set_reservoir_head, set_reservoir_pattern, set_reservoir_coord
+
+from .s4_tanks import OVERFLOW_YES, OVERFLOW_NO
+from .s4_tanks import add_tank, delete_tank
+from .s4_tanks import get_tank_elevation, get_tank_init_level, get_tank_min_level, get_tank_max_level, get_tank_diameter, get_tank_min_vol, get_tank_vol_curve, get_tank_overflow, get_tank_coord
+from .s4_tanks import set_tank_elevation, set_tank_init_level, set_tank_min_level, set_tank_max_level, set_tank_diameter, set_tank_min_vol, set_tank_vol_curve, set_tank_overflow, set_tank_coord
\ No newline at end of file
diff --git a/tjnetwork.py b/tjnetwork.py
index 9e24106..fa7be2c 100644
--- a/tjnetwork.py
+++ b/tjnetwork.py
@@ -19,6 +19,9 @@ PIPE = api.PIPE
 PUMP = api.PUMP
 VALVE = api.VALVE
 
+OVERFLOW_YES = api.OVERFLOW_YES
+OVERFLOW_NO = api.OVERFLOW_NO
+
 
 ############################################################
 # project
@@ -169,3 +172,97 @@ def set_junction_pattern(name: str, junction_id: str, pattern: str) -> ChangeSet
 
 def set_junction_coord(name: str, junction_id: str, x: float, y: float) -> ChangeSet:
     return api.set_junction_coord(name, junction_id, x, y)
+
+
+############################################################
+# reservoir 3.[RESERVOIRS]
+############################################################
+
+def add_reservoir(name: str, reservoir_id: str, x: float, y: float, elevation: float) -> ChangeSet:
+    return api.add_reservoir(name, reservoir_id, x, y, elevation)
+
+def delete_reservoir(name: str, reservoir_id: str) -> ChangeSet:
+    return api.delete_reservoir(name, reservoir_id)
+
+def get_reservoir_head(name: str, reservoir_id: str) -> float | None:
+    return api.get_reservoir_head(name, reservoir_id)
+
+def get_reservoir_pattern(name: str, reservoir_id: str) -> str | None:
+    return api.get_reservoir_pattern(name, reservoir_id)
+
+def get_reservoir_coord(name: str, reservoir_id: str) -> dict[str, float] | None:
+    return api.get_reservoir_coord(name, reservoir_id)
+
+def set_reservoir_head(name: str, reservoir_id: str, elevation: float) -> ChangeSet:
+    return api.set_reservoir_head(name, reservoir_id, elevation)
+
+def set_reservoir_pattern(name: str, reservoir_id: str, pattern: str) -> ChangeSet:
+    return api.set_reservoir_pattern(name, reservoir_id, pattern)
+
+def set_reservoir_coord(name: str, reservoir_id: str, x: float, y: float) -> ChangeSet:
+    return api.set_reservoir_coord(name, reservoir_id, x, y)
+
+
+############################################################
+# tank 4.[TANKS]
+############################################################
+
+def add_tank(name: str, tank_id: str, x: float, y: float, elevation: float) -> ChangeSet:
+    return api.add_tank(name, tank_id, x, y, elevation)
+
+def delete_tank(name: str, tank_id: str) -> ChangeSet:
+    return api.delete_tank(name, tank_id)
+
+def get_tank_elevation(name: str, tank_id: str) -> float | None:
+    return api.get_tank_elevation(name, tank_id)
+
+def get_tank_init_level(name: str, tank_id: str) -> float | None:
+    return api.get_tank_init_level(name, tank_id)
+
+def get_tank_min_level(name: str, tank_id: str) -> float | None:
+    return api.get_tank_min_level(name, tank_id)
+
+def get_tank_max_level(name: str, tank_id: str) -> float | None:
+    return api.get_tank_max_level(name, tank_id)
+
+def get_tank_diameter(name: str, tank_id: str) -> float | None:
+    return api.get_tank_diameter(name, tank_id)
+
+def get_tank_min_vol(name: str, tank_id: str) -> float | None:
+    return api.get_tank_min_vol(name, tank_id)
+
+def get_tank_vol_curve(name: str, tank_id: str) -> str | None:
+    return api.get_tank_vol_curve(name, tank_id)
+
+def get_tank_overflow(name: str, tank_id: str) -> str | None:
+    return api.get_tank_overflow(name, tank_id)
+
+def get_tank_coord(name: str, tank_id: str) -> dict[str, float] | None:
+    return api.get_tank_coord(name, tank_id)
+
+def set_tank_elevation(name: str, tank_id: str, elevation: float) -> ChangeSet:
+    return api.set_tank_elevation(name, tank_id, elevation)
+
+def set_tank_init_level(name: str, tank_id: str, init_level: float) -> ChangeSet:
+    return api.set_tank_init_level(name, tank_id, init_level)
+
+def set_tank_min_level(name: str, tank_id: str, min_level: float) -> ChangeSet:
+    return api.set_tank_min_level(name, tank_id, min_level)
+
+def set_tank_max_level(name: str, tank_id: str, max_level: float) -> ChangeSet:
+    return api.set_tank_max_level(name, tank_id, max_level)
+
+def set_tank_diameter(name: str, tank_id: str, diameter: float) -> ChangeSet:
+    return api.set_tank_diameter(name, tank_id, diameter)
+
+def set_tank_min_vol(name: str, tank_id: str, min_vol: float) -> ChangeSet:
+    return api.set_tank_min_vol(name, tank_id, min_vol)
+
+def set_tank_vol_curve(name: str, tank_id: str, vol_curve: str) -> ChangeSet:
+    return api.set_tank_vol_curve(name, tank_id, vol_curve)
+
+def set_tank_overflow(name: str, tank_id: str, overflow: str) -> ChangeSet:
+    return api.set_tank_overflow(name, tank_id, overflow)
+
+def set_tank_coord(name: str, tank_id: str, x: float, y: float) -> ChangeSet:
+    return api.set_tank_coord(name, tank_id, x, y)