diff --git a/outputs_2017088_Survey2.py b/outputs_2017088_Survey2.py
index 8763cf6..ee9d088 100644
--- a/outputs_2017088_Survey2.py
+++ b/outputs_2017088_Survey2.py
@@ -96,7 +96,7 @@ def make_raster(las, output, lastools_loc, keep_only_ground=False, step=0.2):
         return None
 
 
-def extract_pts(las_in, cp_in, survey_date, keep_only_ground=True):
+def extract_pts(las_in, cp_in, survey_date, beach, keep_only_ground=True):
     """Extract elevations from a las surface based on x and y coordinates.
 
     Requires lastools in system path.
@@ -105,6 +105,7 @@ def extract_pts(las_in, cp_in, survey_date, keep_only_ground=True):
         las_in:            input point cloud (las)
         cp_in:             point coordinates with columns: id, x, y, z (csv)
         survey_date:       survey date string, e.g. '19700101'
+        beach:             beach name
         keep_only_ground:  only keep points classified as 'ground' (boolean)
 
     Returns:
@@ -149,7 +150,32 @@ def extract_pts(las_in, cp_in, survey_date, keep_only_ground=True):
     return df
 
 
+def update_survey_output(df, output_dir):
+    """Update survey profile output csv files with current survey.
 
+    Args:
+        df:         dataframe containing current survey elevations
+        output_dir: directory where csv files are saved
+
+    Returns:
+        None
+    """
+    # Merge current survey with existing data
+    profiles = df['Profile'].unique()
+    for profile in profiles:
+        csv_name = os.path.join(output_dir, profile + '.csv')
+        try:
+            # Load existing results
+            master = pd.read_csv(csv_name)
+        except FileNotFoundError:
+            master = df.copy()
+
+        # Add (or update) current survey
+        current_survey_col = df.columns[-1]
+        master[current_survey_col] = df[current_survey_col]
+
+        # Export updated results
+        master.to_csv(csv_name)
 
 
 def plot_profiles(profile_info, profile, output_loc, LL_limit):
@@ -365,9 +391,8 @@ for i in range(0, len(params_file)): #0, len(params_file)
     make_raster(heatmap_las, output_raster, path_2_lastools, keep_only_ground=True)
 
     #extract the points and get volumes
-    df = extract_pts(final_las, input_csv, survey_date, keep_only_ground=True)
-    update_survey_output(df, output_csv_dir)
-    process_tmp_csv(tmp_csv, survey_date, csv_loc, beach)
+    df = extract_pts(final_las, input_csv, survey_date, beach, keep_only_ground=True)
+    update_survey_output(df, csv_loc)
 
     #colourise the point cloud