diff --git a/src/analysis/forecasted_storm_impacts.py b/src/analysis/forecasted_storm_impacts.py
index 2292598..acfbffe 100644
--- a/src/analysis/forecasted_storm_impacts.py
+++ b/src/analysis/forecasted_storm_impacts.py
@@ -74,6 +74,13 @@ def storm_regime(df_forecasted_impacts):
         "storm_regime",
     ] = "inundation"
 
+    # If there is no dune toe defined, R_high should be compared to dune crest to determine if swash or overwash.
+    df_forecasted_impacts.loc[
+        (df_forecasted_impacts.dune_toe_z.isnull())
+        & (df_forecasted_impacts.R_high <= df_forecasted_impacts.dune_crest_z),
+        "storm_regime",
+    ] = "swash"
+
     return df_forecasted_impacts