diff --git a/api/s3_reservoirs.py b/api/s3_reservoirs.py
index caf8a53..d3a3d7f 100644
--- a/api/s3_reservoirs.py
+++ b/api/s3_reservoirs.py
@@ -13,7 +13,9 @@ def get_reservoir_schema(name: str) -> dict[str, dict[str, Any]]:
 
 
 def get_reservoir(name: str, id: str) -> dict[str, Any]:
-    r = read(name, f"select * from reservoirs where id = '{id}'")
+    r = try_read(name, f"select * from reservoirs where id = '{id}'")
+    if r == None:
+        return {}
     xy = get_node_coord(name, id)
     d = {}
     d['id'] = str(r['id'])
@@ -71,6 +73,10 @@ def set_reservoir_cmd(name: str, cs: ChangeSet) -> DbChangeSet:
 
 
 def set_reservoir(name: str, cs: ChangeSet) -> ChangeSet:
+    if 'id' not in cs.operations[0]:
+        return ChangeSet()
+    if get_reservoir(name, cs.operations[0]['id']) == {}:
+        return ChangeSet()
     return execute_command(name, set_reservoir_cmd(name, cs))
 
 
@@ -92,6 +98,10 @@ def add_reservoir_cmd(name: str, cs: ChangeSet) -> DbChangeSet:
 
 
 def add_reservoir(name: str, cs: ChangeSet) -> ChangeSet:
+    if 'id' not in cs.operations[0]:
+        return ChangeSet()
+    if get_reservoir(name, cs.operations[0]['id']) != {}:
+        return ChangeSet()
     return execute_command(name, add_reservoir_cmd(name, cs))
 
 
@@ -113,6 +123,10 @@ def delete_reservoir_cmd(name: str, cs: ChangeSet) -> DbChangeSet:
 
 
 def delete_reservoir(name: str, cs: ChangeSet) -> ChangeSet:
+    if 'id' not in cs.operations[0]:
+        return ChangeSet()
+    if get_reservoir(name, cs.operations[0]['id']) == {}:
+        return ChangeSet()
     return execute_command(name, delete_reservoir_cmd(name, cs))
 
 
diff --git a/test_tjnetwork.py b/test_tjnetwork.py
index 1eaf3e1..41ab604 100644
--- a/test_tjnetwork.py
+++ b/test_tjnetwork.py
@@ -459,6 +459,8 @@ class TestApi:
         p = 'test_reservoir'
         self.enter(p)
 
+        assert get_reservoir(p, 'r0') == {}
+
         add_reservoir(p, ChangeSet({'id': 'r0', 'x': 0.0, 'y': 10.0, 'head': 20.0}))
         r0 = get_reservoir(p, 'r0')
         assert r0['x'] == 0.0
@@ -495,6 +497,8 @@ class TestApi:
         nodes = get_nodes(p)
         assert len(nodes) == 0
 
+        assert get_reservoir(p, 'r0') == {}
+
         add_reservoir(p, ChangeSet({'id': 'r1', 'x': 0.0, 'y': 10.0, 'head': 20.0}))
         add_reservoir(p, ChangeSet({'id': 'r2', 'x': 0.0, 'y': 10.0, 'head': 20.0}))
         add_reservoir(p, ChangeSet({'id': 'r3', 'x': 0.0, 'y': 10.0, 'head': 20.0}))