diff --git a/src/Solver/RubarBE.py b/src/Solver/RubarBE.py
index ed697e23..52ae75bb 100644
--- a/src/Solver/RubarBE.py
+++ b/src/Solver/RubarBE.py
@@ -220,7 +220,7 @@ class Rubar3(CommandLineSolver):
 
     def _hydraulic_data(self, study, values):
         """Check the single reach data needed by DONNEE, MAIL, CONDIN,
-        FROT, HYDRO, HAMONT and CONDAV, and return them. Raise
+        FROT, HYDRO and CONDAV, and return them. Raise
         RubarExportError with a user message"""
         trad = RunSolverTranslate()
         river = study.river
@@ -240,9 +240,7 @@ class Rubar3(CommandLineSolver):
                 reach=edge.name))
 
         warnings = []
-        boundaries = self._check_boundaries(
-            river, edge, values, warnings
-        )
+        boundaries = self._check_boundaries(river, edge, values)
 
         return {
             "edge": edge,
@@ -260,9 +258,9 @@ class Rubar3(CommandLineSolver):
             return float(old_pamhyr_date_to_timestamp(value))
         return float(value)
 
-    def _check_boundaries(self, river, edge, values, warnings):
+    def _check_boundaries(self, river, edge, values):
         """Liquid boundary conditions used for CONDAM, REGIME and CONDAV.
-        Return {'hydro': bc, 'hamont': bc, 'condav': bc} (or None)"""
+        Return {'hydro': bc, 'condav': bc} (or None)"""
         trad = RunSolverTranslate()
         condam = values.get("rubarbe_condam", "")
         condav = values.get("rubarbe_condav", "")
@@ -275,6 +273,17 @@ class Rubar3(CommandLineSolver):
             raise RubarExportError(trad["boundary_code_unsupported"].format(
                 key="rubarbe_condav", value=condav))
 
+        # rubar_init.f90 reads HAMONT only when REGIME=1 and the
+        # computation never uses its values (HIMP, TA, NT3); CONDAM=2 reads
+        # no upstream level at all. The upstream level would be silently
+        # ignored: refuse both settings.
+        for key, value, unsupported in (("REGIME", regime, "1"),
+                                        ("CONDAM", condam, "2")):
+            if value == unsupported:
+                raise RubarExportError(
+                    trad["upstream_level_unsupported"].format(
+                        setting=f"{key}={value}"))
+
         liquid = [
             bc for bc in river.boundary_condition.get_tab("liquid")
             if not bc.is_deleted() and bc.bctype in self._boundary_kinds
@@ -283,13 +292,9 @@ class Rubar3(CommandLineSolver):
         def at(node):
             return [bc for bc in liquid if bc.node == node]
 
-        upstream_types = list(self._upstream_types[condam])
-        if regime == "1":
-            upstream_types.append("TZ")
         upstream = self._select_boundaries(
-            at(edge.node1), upstream_types, edge.node1,
-            {"TD": f"CONDAM={condam}", "TZ": "REGIME=1"},
-            f"CONDAM={condam}, REGIME={regime}"
+            at(edge.node1), self._upstream_types[condam], edge.node1,
+            {"TD": f"CONDAM={condam}"}, f"CONDAM={condam}"
         )
         downstream = self._select_boundaries(
             at(edge.node2), self._downstream_types[condav], edge.node2,
@@ -297,14 +302,8 @@ class Rubar3(CommandLineSolver):
             f"CONDAV={condav}"
         )
 
-        # rubar_init.f90: HAMONT is read when REGIME=1, but the 2021
-        # code never uses it; CONDAM=2 reads no upstream level at all
-        if regime == "1" or condam == "2":
-            warnings.append(trad["upstream_level_unused"])
-
         return {
             "hydro": upstream.get("TD"),
-            "hamont": upstream.get("TZ"),
             "condav": downstream.get("ZD", downstream.get("TZ")),
         }
 
@@ -818,9 +817,10 @@ class Rubar3(CommandLineSolver):
         self._write_parameters(repertory, f"condin.{name}", lines)
 
     def _export_boundaries(self, hydraulics, repertory, qlog, name="0"):
-        """HYDRO (Q, t), HAMONT (Z, t) and CONDAV ((Q, Z) for a rating
-        curve, (t, Z) for a Z(t) condition), notice annex 1. A file is
-        written only when the matching condition is used"""
+        """HYDRO (Q, t) and CONDAV ((Q, Z) for a rating curve, (t, Z) for
+        a Z(t) condition), notice annex 1. A file is written only when the
+        matching condition is used. HAMONT is not written: REGIME=1 and
+        CONDAM=2 are refused (see _check_boundaries)"""
         bcs = hydraulics["boundaries"]
 
         def records(bc, columns):
@@ -831,10 +831,6 @@ class Rubar3(CommandLineSolver):
             files.append(("hydro", bcs["hydro"],
                           lambda t, q: f"{float(q)!r} {float(t)!r}\n",
                           lambda n: f"{n}\n"))
-        if bcs["hamont"] is not None:
-            files.append(("hamont", bcs["hamont"],
-                          lambda t, z: f"{float(z):15.6f} {float(t):15.6f}\n",
-                          lambda n: f"{n:>6}\n"))
         if bcs["condav"] is not None:
             bc = bcs["condav"]
             if bc.bctype == "ZD":
diff --git a/src/View/RunSolver/Translate.py b/src/View/RunSolver/Translate.py
index dce8b5eb..72e663f2 100644
--- a/src/View/RunSolver/Translate.py
+++ b/src/View/RunSolver/Translate.py
@@ -101,10 +101,11 @@ class RunSolverTranslate(PamhyrTranslate):
             "Export cancelled: the times of boundary condition {name} at "
             "node {node} must be increasing."
         )
-        self._dict["upstream_level_unused"] = _translate(
+        self._dict["upstream_level_unsupported"] = _translate(
             "Solver",
-            "The upstream water level (REGIME=1 or CONDAM=2) is not used "
-            "by the current RubarBE version: the computation ignores it."
+            "Export cancelled: {setting} imposes an upstream water level, "
+            "which the current RubarBE version reads but does not use in "
+            "the computation. Choose another upstream boundary setting."
         )
         self._dict["missing_friction"] = _translate(
             "Solver",