diff --git a/src/troute-network/troute/HYFeaturesNetwork.py b/src/troute-network/troute/HYFeaturesNetwork.py
index fc0cb02f5..59df5ec13 100644
--- a/src/troute-network/troute/HYFeaturesNetwork.py
+++ b/src/troute-network/troute/HYFeaturesNetwork.py
@@ -518,6 +518,7 @@ def preprocess_waterbodies(self, lakes):
             self._waterbody_connections = {}
             self._waterbody_type_specified = False
             self._link_lake_crosswalk = None
+            self._duplicate_ids_df = pd.DataFrame()
 
         self._dataframe = self.dataframe.drop('waterbody', axis=1).drop_duplicates()