diff --git a/transfers/transfer.py b/transfers/transfer.py
index 6e41aa9b..73c82a21 100644
--- a/transfers/transfer.py
+++ b/transfers/transfer.py
@@ -425,7 +425,11 @@ def _run_continuous_water_level_transfers(metrics, flags):
                 results_map[result_name] = result
                 logger.info(f"Parallel task {result_name} completed in {elapsed:.2f}s")
             except Exception as e:
-                logger.critical(f"Parallel task {name} failed: {e}")
+                import traceback
+
+                logger.critical(
+                    f"Parallel task {name} failed: {traceback.format_exc()}"
+                )
 
     if "Pressure" in results_map and results_map["Pressure"]:
         metrics.pressure_metrics(*results_map["Pressure"])
diff --git a/transfers/waterlevels_transducer_transfer.py b/transfers/waterlevels_transducer_transfer.py
index c17de915..8552ca7e 100644
--- a/transfers/waterlevels_transducer_transfer.py
+++ b/transfers/waterlevels_transducer_transfer.py
@@ -154,7 +154,7 @@ def _install_ts(value):
                         insert(TransducerObservation),
                         filtered_observations,
                     )
-                session.add(block)
+                block = self._get_or_create_block(session, block)
                 logger.info(
                     f"Added {len(observations)} water levels {release_status} block"
                 )
@@ -250,6 +250,33 @@ def _build_itertuples_field_map(df: pd.DataFrame) -> dict[str, str]:
                 mapping[col] = field
         return mapping
 
+    def _get_or_create_block(
+        self, session: Session, block: TransducerObservationBlock
+    ) -> TransducerObservationBlock:
+        existing = (
+            session.query(TransducerObservationBlock)
+            .filter(
+                TransducerObservationBlock.thing_id == block.thing_id,
+                TransducerObservationBlock.parameter_id == block.parameter_id,
+                TransducerObservationBlock.review_status == block.review_status,
+                TransducerObservationBlock.start_datetime == block.start_datetime,
+                TransducerObservationBlock.end_datetime == block.end_datetime,
+            )
+            .one_or_none()
+        )
+        if existing:
+            existing.comment = block.comment or existing.comment
+            existing.release_status = block.release_status or existing.release_status
+            existing.reviewer_id = block.reviewer_id or existing.reviewer_id
+            existing.created_by_name = block.created_by_name or existing.created_by_name
+            existing.created_by_id = block.created_by_id or existing.created_by_id
+            existing.updated_by_name = block.updated_by_name or existing.updated_by_name
+            existing.updated_by_id = block.updated_by_id or existing.updated_by_id
+            return existing
+
+        session.add(block)
+        return block
+
 
 class WaterLevelsContinuousPressureTransferer(WaterLevelsContinuousTransferer):
     source_table = "WaterLevelsContinuous_Pressure"
@@ -328,7 +355,12 @@ def _legacy_payload(self, row: pd.Series) -> dict:
 
 
 def _find_deployment(ts, deployments):
-    date = ts.date()
+    if isinstance(ts, Timestamp):
+        date = ts.date()
+    elif hasattr(ts, "date"):
+        date = ts.date()
+    else:
+        date = pd.Timestamp(ts).date()
     for d in deployments:
         if d.installation_date > date:
             break  # because sorted by start