diff --git a/api/s24_coordinates.py b/api/s24_coordinates.py
index 268574a..2337f09 100644
--- a/api/s24_coordinates.py
+++ b/api/s24_coordinates.py
@@ -23,10 +23,7 @@ def get_node_coord(name: str, id: str) -> dict[str, float] | None:
         return _to_point(coord)
 
 
-def set_node_coord(name: str, id: str, x: float, y: float) -> ChangeSet:
-    if not is_junction(name, id):
-        return ChangeSet()
-
+def set_node_coord(name: str, node_type: str, id: str, x: float, y: float) -> ChangeSet:
     old = get_node_coord(name, id)
     if old == None:
         return ChangeSet()
@@ -42,5 +39,5 @@ def set_node_coord(name: str, id: str, x: float, y: float) -> ChangeSet:
         add_operation(name, redo, undo)
 
     change = ChangeSet()
-    change.update('junction', id, 'coord', 'point', str({'x': x, 'y': y}))
+    change.update(node_type, id, 'coord', 'point', str({'x': x, 'y': y}))
     return change
diff --git a/api/s2_junctions.py b/api/s2_junctions.py
index 6c029c0..3e8df88 100644
--- a/api/s2_junctions.py
+++ b/api/s2_junctions.py
@@ -85,4 +85,7 @@ def set_junction_pattern(name: str, id: str, pattern: str) -> ChangeSet:
 
 
 def set_junction_coord(name: str, id: str, x: float, y: float) -> ChangeSet:
-    return set_node_coord(name, id, x, y)
+    if not is_junction(name, id):
+        return ChangeSet()
+
+    return set_node_coord(name, JUNCTION, id, x, y)
diff --git a/api/s3_reservoirs.py b/api/s3_reservoirs.py
index 7eb58bc..7394f75 100644
--- a/api/s3_reservoirs.py
+++ b/api/s3_reservoirs.py
@@ -72,4 +72,7 @@ def set_reservoir_pattern(name: str, id: str, pattern: str) -> ChangeSet:
 
 
 def set_reservoir_coord(name: str, id: str, x: float, y: float) -> ChangeSet:
-    return set_node_coord(name, id, x, y)
+    if not is_reservoir(name, id):
+        return ChangeSet()
+
+    return set_node_coord(name, RESERVOIR, id, x, y)
diff --git a/api/s4_tanks.py b/api/s4_tanks.py
index 1707172..6302ac9 100644
--- a/api/s4_tanks.py
+++ b/api/s4_tanks.py
@@ -142,4 +142,7 @@ def set_tank_overflow(name: str, id: str, overflow: str) -> ChangeSet:
 
 
 def set_tank_coord(name: str, id: str, x: float, y: float) -> ChangeSet:
-    return set_node_coord(name, id, x, y)
+    if not is_tank(name, id):
+        return ChangeSet()
+
+    return set_node_coord(name, TANK, id, x, y)
diff --git a/test_tjnetwork.py b/test_tjnetwork.py
index 9f7e02a..7d47a1a 100644
--- a/test_tjnetwork.py
+++ b/test_tjnetwork.py
@@ -36,7 +36,7 @@ class TestApi:
 
         change_set = add_junction(p, "j0", 0.0, 10.0, 20.0)
         assert len(change_set.added) == 1
-        assert change_set.added[0]['type'] == 'junction'
+        assert change_set.added[0]['type'] == JUNCTION
         assert change_set.added[0]['id'] == "j0"
         coord = get_junction_coord(p, 'j0')
         assert coord['x'] == 0.0
@@ -48,16 +48,18 @@ class TestApi:
         assert get_junction_demand(p, 'j0') == "NULL"
         change_set = set_junction_demand(p, 'j0', 100.0)
         assert len(change_set.updated) == 1
-        assert change_set.updated[0]['type'] == 'junction'
+        assert change_set.updated[0]['type'] == JUNCTION
         assert change_set.updated[0]['id'] == 'j0'
         assert change_set.updated[0]['property'] == 'demand'
         assert change_set.updated[0]['property_type'] == 'float'
         assert change_set.updated[0]['property_value'] == str(100.0)
         assert get_junction_demand(p, 'j0') == 100.0
 
+        # TODO: pattern
+
         change_set = add_junction(p, "j1", 0.0, 10.0, 20.0)
         assert len(change_set.added) == 1
-        assert change_set.added[0]['type'] == 'junction'
+        assert change_set.added[0]['type'] == JUNCTION
         assert change_set.added[0]['id'] == "j1"
 
         nodes = get_nodes(p)
@@ -67,7 +69,7 @@ class TestApi:
 
         change_set = delete_junction(p, 'j1')
         assert len(change_set.deleted) == 1
-        assert change_set.deleted[0]['type'] == 'junction'
+        assert change_set.deleted[0]['type'] == JUNCTION
         assert change_set.deleted[0]['id'] == "j1"
 
         nodes = get_nodes(p)
@@ -76,7 +78,7 @@ class TestApi:
 
         change_set = delete_junction(p, 'j0')
         assert len(change_set.deleted) == 1
-        assert change_set.deleted[0]['type'] == 'junction'
+        assert change_set.deleted[0]['type'] == JUNCTION
         assert change_set.deleted[0]['id'] == "j0"
 
         nodes = get_nodes(p)
@@ -84,10 +86,39 @@ class TestApi:
 
         self.leave(p)
 
-        pass
-
     def test_reservoir(self):
-        pass
+        p = "test_reservoir"
+        self.enter(p)
+
+        change_set = add_reservoir(p, "r0", 0.0, 10.0, 20.0)
+        assert len(change_set.added) == 1
+        assert change_set.added[0]['type'] == RESERVOIR
+        assert change_set.added[0]['id'] == "r0"
+
+        assert get_reservoir_head(p, 'r0') == 20.0
+        change_set = set_reservoir_head(p, 'r0', 100.0)
+        assert change_set.updated[0]['type'] == RESERVOIR
+        assert change_set.updated[0]['id'] == 'r0'
+        assert change_set.updated[0]['property'] == 'head'
+        assert change_set.updated[0]['property_type'] == 'float'
+        assert change_set.updated[0]['property_value'] == str(100.0)
+        assert get_reservoir_head(p, 'r0') == 100.0
+
+        assert get_reservoir_coord(p, 'r0') == { 'x': 0.0, 'y': 10.0 }
+        change_set = set_reservoir_coord(p, 'r0', 100.0, 200.0)
+        assert change_set.updated[0]['type'] == RESERVOIR
+        assert change_set.updated[0]['id'] == 'r0'
+        assert change_set.updated[0]['property'] == 'coord'
+        assert change_set.updated[0]['property_type'] == 'point'
+        assert change_set.updated[0]['property_value'] == str({'x': 100.0, 'y': 200.0})
+        assert get_reservoir_coord(p, 'r0') == { 'x': 100.0, 'y': 200.0 }
+
+        change_set = delete_reservoir(p, 'r0')
+        assert len(change_set.deleted) == 1
+        assert change_set.deleted[0]['type'] == RESERVOIR
+        assert change_set.deleted[0]['id'] == "r0"
+
+        self.leave(p)
 
     def test_tank(self):
         pass
diff --git a/tjnetwork.py b/tjnetwork.py
index f5b215d..9d8cddb 100644
--- a/tjnetwork.py
+++ b/tjnetwork.py
@@ -189,8 +189,8 @@ def set_junction_coord(name: str, junction_id: str, x: float, y: float) -> Chang
 # 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 add_reservoir(name: str, reservoir_id: str, x: float, y: float, head: float) -> ChangeSet:
+    return api.add_reservoir(name, reservoir_id, x, y, head)
 
 def delete_reservoir(name: str, reservoir_id: str) -> ChangeSet:
     return api.delete_reservoir(name, reservoir_id)
@@ -204,8 +204,8 @@ def get_reservoir_pattern(name: str, reservoir_id: str) -> str | None:
 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_head(name: str, reservoir_id: str, head: float) -> ChangeSet:
+    return api.set_reservoir_head(name, reservoir_id, head)
 
 def set_reservoir_pattern(name: str, reservoir_id: str, pattern: str) -> ChangeSet:
     return api.set_reservoir_pattern(name, reservoir_id, pattern)