diff --git a/src/Model/AdditionalFile/AddFile.py b/src/Model/AdditionalFile/AddFile.py
index d3b027ea..25db92bf 100644
--- a/src/Model/AdditionalFile/AddFile.py
+++ b/src/Model/AdditionalFile/AddFile.py
@@ -216,7 +216,9 @@ class AddFile(SQLSubModel):
             "additional_files(pamhyr_id, enabled, deleted, " +
             "name, path, text, scenario) " +
             "VALUES (" +
-            f"{self._pamhyr_id}, {self._enabled}, {self.is_deleted()}, " +
+            f"{self._pamhyr_id}, " +
+            f"{self._db_format(self._enabled)}, " +
+            f"{self._db_format(self.is_deleted())}, " +
             f"'{self._db_format(self._name)}', " +
             f"'{self._db_format(self._path)}', " +
             f"'{self._db_format(self._text)}', " +
diff --git a/src/Model/HydraulicStructures/Basic/HydraulicStructures.py b/src/Model/HydraulicStructures/Basic/HydraulicStructures.py
index 400308a4..e32b9d45 100644
--- a/src/Model/HydraulicStructures/Basic/HydraulicStructures.py
+++ b/src/Model/HydraulicStructures/Basic/HydraulicStructures.py
@@ -35,13 +35,13 @@ class BasicHS(SQLSubModel):
     _sub_classes = [
         BHSValue,
     ]
-    _id_cnt = 0
 
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
-        super(BasicHS, self).__init__(id)
-
-        self._status = status
+                 status=None, owner_scenario=-1):
+        super(BasicHS, self).__init__(
+            id=id, status=status,
+            owner_scenario=owner_scenario
+        )
 
         self._name = name
         self._type = ""
@@ -53,6 +53,7 @@ class BasicHS(SQLSubModel):
         execute(f"""
           CREATE TABLE hydraulic_structures_basic{ext} (
             {cls.create_db_add_pamhyr_id()},
+            deleted BOOLEAN NOT NULL DEFAULT FALSE,
             name TEXT NOT NULL,
             type TEXT NOT NULL,
             enabled BOOLEAN NOT NULL,
@@ -79,6 +80,13 @@ class BasicHS(SQLSubModel):
             else:
                 cls._db_update_to_0_1_0(execute, data)
 
+        if major == "0" and minor == "1":
+            if release < 2:
+                execute(
+                    "ALTER TABLE hydraulic_structures_basic " +
+                    "ADD COLUMN deleted BOOLEAN NOT NULL DEFAULT FALSE"
+                )
+
         return cls._update_submodel(execute, version, data)
 
     @classmethod
@@ -135,28 +143,39 @@ class BasicHS(SQLSubModel):
     @classmethod
     def _db_load(cls, execute, data=None):
         new = []
+        status = data["status"]
+        scenario = data["scenario"]
+        loaded = data['loaded_pid']
+
+        if scenario is None:
+            return []
 
         table = execute(
-            "SELECT pamhyr_id, name, type, enabled, hs " +
+            "SELECT pamhyr_id, deleted, name, type, enabled, hs, scenario " +
             "FROM hydraulic_structures_basic " +
-            f"WHERE hs = {data['hs_id']} "
+            f"WHERE hs = {data['hs_id']} " +
+            f"AND scenario = {scenario.id} " +
+            f"AND pamhyr_id NOT IN ({', '.join(map(str, loaded))})"
         )
 
         for row in table:
             it = iter(row)
 
             bhs_pid = next(it)
+            deleted = (next(it) == 1)
             name = next(it)
             type = next(it)
             enabled = (next(it) == 1)
             hs_id = next(it)
+            owner_scenario = next(it)
 
             ctor = cls._get_ctor_from_type(type)
             bhs = ctor(
-                id=bhs_pid,
-                name=name,
-                status=data['status']
+                id=bhs_pid, name=name,
+                status=status, owner_scenario=owner_scenario
             )
+            if deleted:
+                bhs.set_as_deleted()
 
             bhs.enabled = enabled
 
@@ -164,31 +183,45 @@ class BasicHS(SQLSubModel):
             bhs._data = BHSValue._db_load(
                 execute, data
             )
+            print(f"{bhs_pid} : {deleted}")
+            if deleted:
+                bhs.set_as_deleted()
 
             new.append(bhs)
+            loaded.add(bhs_pid)
+
+        data["scenario"] = scenario.parent
+        new += cls._db_load(execute, data)
+        data["scenario"] = scenario
 
         return new
 
     def _db_save(self, execute, data=None):
+        if not self.must_be_saved():
+            return True
+
         hs_id = data['hs_id']
 
-        sql = (
+        execute(
             "INSERT INTO " +
-            "hydraulic_structures_basic(pamhyr_id, name, type, enabled, hs) " +
+            "hydraulic_structures_basic(pamhyr_id, deleted, " +
+            "name, type, enabled, hs, scenario) " +
             "VALUES (" +
             f"{self.pamhyr_id}, " +
+            f"{self._db_format(self.is_deleted())}, " +
             f"'{self._db_format(self._name)}', " +
             f"'{self._db_format(self._type)}', " +
             f"{self._db_format(self.enabled)}, " +
-            f"{hs_id} " +
+            f"{hs_id}, " +
+            f"{self._status.scenario_id}"
             ")"
         )
-        execute(sql)
 
         data['bhs_id'] = self.pamhyr_id
         execute(
             "DELETE FROM hydraulic_structures_basic_value " +
-            f"WHERE bhs = {self.pamhyr_id}"
+            f"WHERE bhs = {self.pamhyr_id} " +
+            f"AND scenario = {self._status.scenario_id}"
         )
 
         for values in self._data:
@@ -209,7 +242,7 @@ class BasicHS(SQLSubModel):
     @name.setter
     def name(self, name):
         self._name = name
-        self._status.modified()
+        self.modified()
 
     @property
     def type(self):
@@ -218,7 +251,7 @@ class BasicHS(SQLSubModel):
     @type.setter
     def type(self, type):
         self._type = type
-        self._status.modified()
+        self.modified()
 
     @property
     def enabled(self):
@@ -227,7 +260,7 @@ class BasicHS(SQLSubModel):
     @enabled.setter
     def enabled(self, enabled):
         self._enabled = enabled
-        self._status.modified()
+        self.modified()
 
     @property
     def parameters(self):
diff --git a/src/Model/HydraulicStructures/Basic/Types.py b/src/Model/HydraulicStructures/Basic/Types.py
index b125541d..86fbd419 100644
--- a/src/Model/HydraulicStructures/Basic/Types.py
+++ b/src/Model/HydraulicStructures/Basic/Types.py
@@ -27,10 +27,11 @@ from Model.HydraulicStructures.Basic.Value import (
 
 class NotDefined(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(NotDefined, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "ND"
@@ -39,10 +40,11 @@ class NotDefined(BasicHS):
 
 class DischargeWeir(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(DischargeWeir, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "S1"
@@ -55,10 +57,11 @@ class DischargeWeir(BasicHS):
 
 class TrapezoidalWeir(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(TrapezoidalWeir, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "S2"
@@ -73,10 +76,11 @@ class TrapezoidalWeir(BasicHS):
 
 class TriangularWeir(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(TriangularWeir, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "S3"
@@ -90,10 +94,11 @@ class TriangularWeir(BasicHS):
 
 class RectangularOrifice(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(RectangularOrifice, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "OR"
@@ -110,10 +115,11 @@ class RectangularOrifice(BasicHS):
 
 class CircularOrifice(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(CircularOrifice, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "OC"
@@ -127,10 +133,11 @@ class CircularOrifice(BasicHS):
 
 class VaultedOrifice(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(VaultedOrifice, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "OV"
@@ -145,10 +152,11 @@ class VaultedOrifice(BasicHS):
 
 class RectangularGate(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(RectangularGate, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "V1"
@@ -163,10 +171,11 @@ class RectangularGate(BasicHS):
 
 class SimplifiedRectangularGate(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(SimplifiedRectangularGate, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "V2"
@@ -181,10 +190,11 @@ class SimplifiedRectangularGate(BasicHS):
 
 class Borda(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(Borda, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "BO"
@@ -197,10 +207,11 @@ class Borda(BasicHS):
 
 class CheckValve(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(CheckValve, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "CV"
@@ -217,10 +228,11 @@ class CheckValve(BasicHS):
 
 class UserDefined(BasicHS):
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
+                 status=None, owner_scenario=-1):
         super(UserDefined, self).__init__(
             id=id, name=name,
-            status=status
+            status=status,
+            owner_scenario=owner_scenario
         )
 
         self._type = "UD"
diff --git a/src/Model/HydraulicStructures/Basic/Value.py b/src/Model/HydraulicStructures/Basic/Value.py
index 1d4c870d..cf4bf40b 100644
--- a/src/Model/HydraulicStructures/Basic/Value.py
+++ b/src/Model/HydraulicStructures/Basic/Value.py
@@ -26,10 +26,11 @@ class BHSValue(SQLSubModel):
 
     def __init__(self, id: int = -1, name: str = "",
                  type=float, value=0.0,
-                 status=None):
-        super(BHSValue, self).__init__(id)
-
-        self._status = status
+                 status=None, owner_scenario=-1):
+        super(BHSValue, self).__init__(
+            id=id, status=status,
+            owner_scenario=owner_scenario
+        )
 
         self._name = name
         self._type = type
@@ -132,12 +133,20 @@ class BHSValue(SQLSubModel):
     @classmethod
     def _db_load(cls, execute, data=None):
         new = []
+        status = data["status"]
+        scenario = data["scenario"]
+        loaded = data['loaded_pid']
         bhs_id = data["bhs_id"]
 
+        if scenario is None:
+            return []
+
         table = execute(
-            "SELECT pamhyr_id, name, type, value " +
+            "SELECT pamhyr_id, name, type, value, scenario " +
             "FROM hydraulic_structures_basic_value " +
-            f"WHERE bhs = '{bhs_id}'"
+            f"WHERE bhs = '{bhs_id}' " +
+            f"AND scenario = {scenario.id} " +
+            f"AND pamhyr_id NOT IN ({', '.join(map(str, loaded))})"
         )
 
         for row in table:
@@ -147,14 +156,20 @@ class BHSValue(SQLSubModel):
             name = next(it)
             type = cls._str_to_type(next(it))
             value = next(it)
+            owner_scenario = next(it)
 
             val = cls(
                 id=pid, name=name,
                 type=type, value=value,
-                status=data['status']
+                status=status, owner_scenario=owner_scenario
             )
 
             new.append(val)
+            loaded.add(pid)
+
+        data["scenario"] = scenario.parent
+        new += cls._db_load(execute, data)
+        data["scenario"] = scenario
 
         return new
 
@@ -164,13 +179,14 @@ class BHSValue(SQLSubModel):
         execute(
             "INSERT INTO " +
             "hydraulic_structures_basic_value" +
-            "(pamhyr_id, name, type, value, bhs) " +
+            "(pamhyr_id, name, type, value, bhs, scenario) " +
             "VALUES (" +
             f"{self._pamhyr_id}, " +
             f"'{self._db_format(self._name)}', " +
             f"'{self._db_format(self._type_to_str(self._type))}', " +
             f"'{self._db_format(self._value)}', " +
-            f"{bhs_id}" +
+            f"{bhs_id}, " +
+            f"{self._status.scenario_id}"
             ")"
         )
 
@@ -191,4 +207,4 @@ class BHSValue(SQLSubModel):
     @value.setter
     def value(self, value):
         self._value = self._type(value)
-        self._status.modified()
+        self.modified()
diff --git a/src/Model/HydraulicStructures/HydraulicStructures.py b/src/Model/HydraulicStructures/HydraulicStructures.py
index 1c93441e..350a48ee 100644
--- a/src/Model/HydraulicStructures/HydraulicStructures.py
+++ b/src/Model/HydraulicStructures/HydraulicStructures.py
@@ -37,13 +37,13 @@ class HydraulicStructure(SQLSubModel):
     _sub_classes = [
         BasicHS,
     ]
-    _id_cnt = 0
 
     def __init__(self, id: int = -1, name: str = "",
-                 status=None):
-        super(HydraulicStructure, self).__init__(id)
-
-        self._status = status
+                 status=None, owner_scenario=-1):
+        super(HydraulicStructure, self).__init__(
+            id=id, status=status,
+            owner_scenario=owner_scenario
+        )
 
         self._name = name
         self._input_section = None
@@ -58,6 +58,7 @@ class HydraulicStructure(SQLSubModel):
         execute(f"""
           CREATE TABLE hydraulic_structures{ext} (
             {cls.create_db_add_pamhyr_id()},
+            deleted BOOLEAN NOT NULL DEFAULT FALSE,
             name TEXT NOT NULL,
             enabled BOOLEAN NOT NULL,
             input_reach INTEGER,
@@ -84,9 +85,9 @@ class HydraulicStructure(SQLSubModel):
     @classmethod
     def _db_update(cls, execute, version, data=None):
         major, minor, release = version.strip().split(".")
-        if major == minor == "0":
-            rl = int(release)
+        rl = int(release)
 
+        if major == minor == "0":
             if rl < 6:
                 cls._db_create(execute)
                 return True
@@ -103,9 +104,16 @@ class HydraulicStructure(SQLSubModel):
             cls._db_update_to_0_1_0(execute, data)
 
         if major == "0" and minor == "1":
-            if int(release) < 1:
+            if rl < 1:
                 cls._db_update_to_0_1_1(execute, data)
 
+            if rl < 2:
+                execute(
+                    "ALTER TABLE hydraulic_structures " +
+                    "ADD COLUMN deleted BOOLEAN NOT NULL DEFAULT FALSE"
+                )
+
+
         return cls._update_submodel(execute, version, data)
 
     @classmethod
@@ -181,70 +189,97 @@ class HydraulicStructure(SQLSubModel):
     @classmethod
     def _db_load(cls, execute, data=None):
         new = []
+        status = data["status"]
+        scenario = data["scenario"]
+        loaded = data['loaded_pid']
+
+        if scenario is None:
+            return []
 
         table = execute(
-            "SELECT pamhyr_id, name, enabled, " +
+            "SELECT pamhyr_id, deleted, name, enabled, " +
             "input_section, output_section, " +
-            "input_reach, output_reach " +
-            "FROM hydraulic_structures"
+            "input_reach, output_reach, scenario " +
+            "FROM hydraulic_structures " +
+            f"WHERE scenario = {scenario.id} " +
+            f"AND pamhyr_id NOT IN ({', '.join(map(str, loaded))})"
         )
 
         for row in table:
-            it = iter(row)
+            new.append(cls._db_load_new(execute, data, row))
 
-            hs_id = next(it)
-            name = next(it)
-            enabled = (next(it) == 1)
-            input_section_id = next(it)
-            input_section_id = (
-                -1 if input_section_id is None else input_section_id
-            )
-            output_section_id = next(it)
-            output_section_id = (
-                -1 if output_section_id is None else output_section_id
-            )
-            input_reach_id = next(it)
-            output_reach_id = next(it)
-
-            hs = cls(
-                id=hs_id, name=name, status=data['status']
-            )
-
-            hs.enabled = enabled
-            hs.input_reach, hs.output_reach = reduce(
-                lambda acc, n: (
-                    n if n.pamhyr_id == input_reach_id else acc[0],
-                    n if n.pamhyr_id == output_reach_id else acc[1]
-                ),
-                data["edges"],
-                [None, None]
-            )
-            sections = []
-            if hs.input_reach is not None:
-                sections += hs.input_reach.reach.profiles
-            if hs.output_reach is not None:
-                sections += hs.output_reach.reach.profiles
-
-            hs.input_section, hs.output_section = reduce(
-                lambda acc, s: (
-                    s if s.pamhyr_id == input_section_id else acc[0],
-                    s if s.pamhyr_id == output_section_id else acc[1]
-                ),
-                sections,
-                [None, None]
-            )
-
-            data['hs_id'] = hs_id
-            hs._data = BasicHS._db_load(execute, data)
-
-            new.append(hs)
+        data["scenario"] = scenario.parent
+        new += cls._db_load(execute, data)
+        data["scenario"] = scenario
 
         return new
 
+    @classmethod
+    def _db_load_new(cls, execute, data, row):
+        it = iter(row)
+        status = data["status"]
+        scenario = data["scenario"]
+        loaded = data['loaded_pid']
+
+        hs_id = next(it)
+        deleted = (next(it) == 1)
+        name = next(it)
+        enabled = (next(it) == 1)
+        input_section_id = next(it)
+        input_section_id = (
+            -1 if input_section_id is None else input_section_id
+        )
+        output_section_id = next(it)
+        output_section_id = (
+            -1 if output_section_id is None else output_section_id
+        )
+        input_reach_id = next(it)
+        output_reach_id = next(it)
+        owner_scenario = next(it)
+
+        hs = cls(
+            id=hs_id, name=name, status=status,
+            owner_scenario=owner_scenario
+        )
+        if deleted:
+            new.set_as_deleted()
+
+        hs.enabled = enabled
+        hs.input_reach, hs.output_reach = reduce(
+            lambda acc, n: (
+                n if n.pamhyr_id == input_reach_id else acc[0],
+                n if n.pamhyr_id == output_reach_id else acc[1]
+            ),
+            data["edges"],
+            [None, None]
+        )
+        sections = []
+        if hs.input_reach is not None:
+            sections += hs.input_reach.reach.profiles
+        if hs.output_reach is not None:
+            sections += hs.output_reach.reach.profiles
+
+        hs.input_section, hs.output_section = reduce(
+            lambda acc, s: (
+                s if s.pamhyr_id == input_section_id else acc[0],
+                s if s.pamhyr_id == output_section_id else acc[1]
+            ),
+            sections,
+            [None, None]
+        )
+
+        loaded.add(hs_id)
+
+        data['hs_id'] = hs_id
+        hs._data = BasicHS._db_load(execute, data)
+
+        return hs
+
     def _db_save(self, execute, data=None):
         execute(
             "DELETE FROM hydraulic_structures " +
-            f"WHERE pamhyr_id = {self.pamhyr_id}"
+            f"WHERE pamhyr_id = {self.pamhyr_id} " +
+            f"AND scenario = {self._status.scenario_id}"
         )
 
         input_reach_id = -1
@@ -266,21 +301,27 @@ class HydraulicStructure(SQLSubModel):
         execute(
             "INSERT INTO " +
             "hydraulic_structures(" +
-            "  pamhyr_id, name, enabled, input_section, output_section, " +
-            "  input_reach, output_reach" +
+            "  pamhyr_id, deleted, name, enabled, " +
+            "  input_section, output_section, " +
+            "  input_reach, output_reach, " +
+            "  scenario" +
             ") " +
             "VALUES (" +
-            f"{self.pamhyr_id}, '{self._db_format(self._name)}', " +
+            f"{self.pamhyr_id}, " +
+            f"{self._db_format(self.is_deleted())}, " +
+            f"'{self._db_format(self._name)}', " +
             f"{self._db_format(self.enabled)}, " +
             f"{input_section}, {output_section}, " +
-            f"{input_reach_id}, {output_reach_id}" +
+            f"{input_reach_id}, {output_reach_id}, " +
+            f"{self._status.scenario_id}"
             ")"
         )
 
         data['hs_id'] = self.pamhyr_id
         execute(
             "DELETE FROM hydraulic_structures_basic " +
-            f"WHERE hs = {self.pamhyr_id}"
+            f"WHERE hs = {self.pamhyr_id} " +
+            f"AND scenario = {self._status.scenario_id}"
         )
 
         for basic in self._data:
@@ -289,7 +330,16 @@ class HydraulicStructure(SQLSubModel):
         return True
 
     def __len__(self):
-        return len(self._data)
+        return len(self.lst)
+
+    @property
+    def lst(self):
+        return list(
+            filter(
+                lambda bhs: not bhs.is_deleted(),
+                self._data,
+            )
+        )
 
     @property
     def name(self):
@@ -301,7 +351,7 @@ class HydraulicStructure(SQLSubModel):
     @name.setter
     def name(self, name):
         self._name = name
-        self._status.modified()
+        self.modified()
 
     @property
     def input_rk(self):
@@ -322,7 +372,7 @@ class HydraulicStructure(SQLSubModel):
     @input_section.setter
     def input_section(self, input_section):
         self._input_section = input_section
-        self._status.modified()
+        self.modified()
 
     @property
     def output_section(self):
@@ -331,7 +381,7 @@ class HydraulicStructure(SQLSubModel):
     @output_section.setter
     def output_section(self, output_section):
         self._output_section = output_section
-        self._status.modified()
+        self.modified()
 
     @property
     def enabled(self):
@@ -340,7 +390,7 @@ class HydraulicStructure(SQLSubModel):
     @enabled.setter
     def enabled(self, enabled):
         self._enabled = enabled
-        self._status.modified()
+        self.modified()
 
     @property
     def input_reach(self):
@@ -349,7 +399,7 @@ class HydraulicStructure(SQLSubModel):
     @input_reach.setter
     def input_reach(self, input_reach):
         self._input_reach = input_reach
-        self._status.modified()
+        self.modified()
 
     @property
     def output_reach(self):
@@ -358,26 +408,31 @@ class HydraulicStructure(SQLSubModel):
     @output_reach.setter
     def output_reach(self, output_reach):
         self._output_reach = output_reach
-        self._status.modified()
+        self.modified()
 
     @property
     def basic_structures(self):
-        return self._data.copy()
+        return self.lst.copy()
 
     def basic_structure(self, index: int):
-        return self._data[index]
+        return self.lst[index]
 
     def add(self, index: int):
         value = NotDefined(status=self._status)
         self._data.insert(index, value)
-        self._status.modified()
+
+        self.modified()
         return value
 
     def insert(self, index: int, value: BasicHS):
-        self._data.insert(index, value)
-        self._status.modified()
+        if value in self._data:
+            value.set_as_not_deleted()
+        else:
+            self._data.insert(index, value)
 
-    def delete_i(self, indexes):
+        self.modified()
+
+    def hard_delete_i(self, indexes):
         self._data = list(
             map(
                 lambda e: e[1],
@@ -387,20 +442,30 @@ class HydraulicStructure(SQLSubModel):
                 )
             )
         )
-        self._status.modified()
+        self.modified()
 
-    def delete(self, els):
-        self._data = list(
-            filter(
-                lambda e: e not in els,
-                self._data
+    def delete_i(self, indexes):
+        list(
+            map(
+                lambda e: e[1].set_as_deleted(),
+                filter(
+                    lambda e: e[0] in indexes,
+                    enumerate(self.lst)
+                )
             )
         )
-        self._status.modified()
+        self.modified()
+
+    def delete(self, els):
+        for el in els:
+            el.set_as_deleted()
+
+        self.modified()
 
     def sort(self, _reverse=False, key=None):
         if key is None:
             self._data.sort(reverse=_reverse)
         else:
             self._data.sort(reverse=_reverse, key=key)
-        self._status.modified()
+
+        self.modified()
diff --git a/src/Model/HydraulicStructures/HydraulicStructuresList.py b/src/Model/HydraulicStructures/HydraulicStructuresList.py
index c19977fe..24f9e95d 100644
--- a/src/Model/HydraulicStructures/HydraulicStructuresList.py
+++ b/src/Model/HydraulicStructures/HydraulicStructuresList.py
@@ -19,7 +19,7 @@
 from copy import copy
 from tools import trace, timer
 
-from Model.Tools.PamhyrList import PamhyrModelList
+from Model.Tools.PamhyrListExt import PamhyrModelList
 from Model.HydraulicStructures.HydraulicStructures import HydraulicStructure
 
 
@@ -42,10 +42,10 @@ class HydraulicStructureList(PamhyrModelList):
         return new
 
     def _db_save(self, execute, data=None):
-        execute("DELETE FROM hydraulic_structures")
-
-        if data is None:
-            data = {}
+        execute(
+            "DELETE FROM hydraulic_structures " +
+            f"WHERE scenario = {self._status.scenario_id}"
+        )
 
         for hs in self._lst:
             hs._db_save(execute, data=data)
@@ -53,9 +53,12 @@ class HydraulicStructureList(PamhyrModelList):
         return True
 
     def new(self, lst, index):
-        n = HydraulicStructure(status=self._status)
+        n = HydraulicStructure(
+            status=self._status,
+            owner_scenario=self._status.scenario_id
+        )
         self._lst.insert(index, n)
-        self._status.modified()
+        self.modified()
         return n
 
     def __copy__(self):
diff --git a/src/Model/Stricklers/Stricklers.py b/src/Model/Stricklers/Stricklers.py
index 6e63a75e..feda6801 100644
--- a/src/Model/Stricklers/Stricklers.py
+++ b/src/Model/Stricklers/Stricklers.py
@@ -23,7 +23,6 @@ from Model.Scenario import Scenario
 
 
 class Stricklers(SQLSubModel):
-    _id_cnt = 0
     _sub_classes = []
 
     def __init__(self, id: int = -1,
@@ -33,9 +32,9 @@ class Stricklers(SQLSubModel):
                  medium: float = 15.0,
                  status=None, owner_scenario=-1):
         super(Stricklers, self).__init__(
-            id=id, owner_scenario=owner_scenario
+            id=id, status=status,
+            owner_scenario=owner_scenario
         )
-        self._status = status
 
         self._name = name
         self._comment = comment
@@ -111,7 +110,6 @@ class Stricklers(SQLSubModel):
             "FROM stricklers " +
             f"WHERE scenario = {scenario.id} " +
             f"AND pamhyr_id NOT IN ({', '.join(map(str, loaded))})"
-
         )
 
         if table is None:
@@ -129,9 +127,7 @@ class Stricklers(SQLSubModel):
             owner_scenario = next(it)
 
             new = cls(
-                id=pid,
-                name=name,
-                comment=comment,
+                id=pid, name=name, comment=comment,
                 minor=minor, medium=medium,
                 status=status, owner_scenario=owner_scenario
             )
@@ -157,7 +153,7 @@ class Stricklers(SQLSubModel):
             "name, comment, minor, medium, scenario) " +
             "VALUES (" +
             f"{self.pamhyr_id}, " +
-            f"{self.is_deleted()}, " +
+            f"{self._db_format(self.is_deleted())}, " +
             f"'{self._db_format(self.name)}', " +
             f"'{self._db_format(self.comment)}', " +
             f"{float(self.minor)}, {float(self.medium)}, " +
diff --git a/src/View/HydraulicStructures/BasicHydraulicStructures/UndoCommand.py b/src/View/HydraulicStructures/BasicHydraulicStructures/UndoCommand.py
index 78fa3d62..c4e084eb 100644
--- a/src/View/HydraulicStructures/BasicHydraulicStructures/UndoCommand.py
+++ b/src/View/HydraulicStructures/BasicHydraulicStructures/UndoCommand.py
@@ -49,14 +49,14 @@ class SetTypeCommand(QUndoCommand):
         self._type = new_type
         self._old = self._hs.basic_structure(self._index)
         self._new = self._hs.basic_structure(self._index)\
-            .convert(self._type)
+                            .convert(self._type)
 
     def undo(self):
-        self._hs.delete_i([self._index])
+        self._hs.hard_delete_i([self._index])
         self._hs.insert(self._index, self._old)
 
     def redo(self):
-        self._hs.delete_i([self._index])
+        self._hs.hard_delete_i([self._index])
         self._hs.insert(self._index, self._new)
 
 
diff --git a/src/View/HydraulicStructures/UndoCommand.py b/src/View/HydraulicStructures/UndoCommand.py
index 4dba1ec7..d9268a76 100644
--- a/src/View/HydraulicStructures/UndoCommand.py
+++ b/src/View/HydraulicStructures/UndoCommand.py
@@ -50,20 +50,22 @@ class SetReachCommand(QUndoCommand):
 
         self._h_s_lst = h_s_lst
         self._index = index
-        self._old = self._h_s_lst.get(self._index).input_reach
+        self._old = self._h_s_lst.get(self._index)\
+                                 .input_reach
         self._new = reach
-        self._old_rk = self._h_s_lst.get(self._index).input_rk
-        self._new_rk = None
+        self._old_section = self._h_s_lst.get(self._index)\
+                                         .input_section
+        self._new_section = None
 
     def undo(self):
         i = self._h_s_lst.get(self._index)
         i.input_reach = self._old
-        i.input_rk = self._old_rk
+        i.input_section = self._old_section
 
     def redo(self):
         i = self._h_s_lst.get(self._index)
         i.input_reach = self._new
-        i.input_rk = self._new_rk
+        i.input_section = self._new_section
 
 
 class SetSectionCommand(QUndoCommand):
@@ -114,7 +116,7 @@ class AddCommand(QUndoCommand):
         if self._new is None:
             self._new = self._h_s_lst.new(self._h_s_lst, self._index)
         else:
-            self._h_s_lst.insert(self._index, self._new)
+            self._h_s_lst.undelete([self._new])
 
 
 class DelCommand(QUndoCommand):
@@ -127,12 +129,11 @@ class DelCommand(QUndoCommand):
 
         self._h_s = []
         for row in rows:
-            self._h_s.append((row, self._h_s_lst.get(row)))
+            self._h_s.append(self._h_s_lst.get(row))
         self._h_s.sort()
 
     def undo(self):
-        for row, el in self._h_s:
-            self._h_s_lst.insert(row, el)
+        self._h_s_lst.undelete(self._h_s)
 
     def redo(self):
         self._h_s_lst.delete_i(self._rows)
diff --git a/src/tools.py b/src/tools.py
index af9592df..bd23f9cc 100644
--- a/src/tools.py
+++ b/src/tools.py
@@ -127,6 +127,9 @@ def display_timers():
     )
 
     for func, time, calls in lst:
+        if time <= 0.000001:
+            continue
+
         name = (f"{logger_color_blue()}{func.__module__}" +
                 f"{logger_color_reset()}" +
                 f".{logger_color_green()}" +