diff --git a/waternsw_grabber/waternsw_grabber.py b/waternsw_grabber/waternsw_grabber.py
index 0575048..96577be 100644
--- a/waternsw_grabber/waternsw_grabber.py
+++ b/waternsw_grabber/waternsw_grabber.py
@@ -249,6 +249,12 @@ def extract_records(input_dir, output_dir, clean_up=False):
     # Prepare output directory
     os.makedirs(output_dir, exist_ok=True)
 
+    # Create master dataframe
+    periods = ['all', 'weekly']
+    master = {}
+    for period in periods:
+        master[period] = pd.DataFrame()
+
     for zip_name in tqdm(zip_names):
         # Skip duplicate downloads
         if re.search('\([0-9]+\)', zip_name):
@@ -278,13 +284,8 @@ def extract_records(input_dir, output_dir, clean_up=False):
         bore_id = re.search('^\S+', meta).group()
         site, hole, pipe = bore_id.split('.')
 
-        # Add bore specifics to dataframe
-        df['Site'] = site
-        df['Hole'] = hole
-        df['Pipe'] = pipe
-        df['Lat'] = lat
-        df['Lon'] = lon
-        df['Elev'] = elev
+        # FIXME: detect basin automatically
+        basin_id = 'MB'
 
         # Rename columns
         df = df.rename(
@@ -296,23 +297,47 @@ def extract_records(input_dir, output_dir, clean_up=False):
 
         # Select output columns
         df = df[[
-            'Site',
-            'Hole',
-            'Pipe',
             'Date time',
             'Below Measuring Point',
             'Above Sea Level',
-            'Lat',
-            'Lon',
-            'Elev',
         ]]
 
-        # Get csv name from zip archive
-        csv_name = os.path.join(output_dir, zip_name.replace('.zip', '.csv'))
+        # Set date index for resampling
+        df.index = df['Date time']
 
-        # Export to csv
-        df.to_csv(csv_name, float_format='%0.3f')
+        # Append to master dataframe
+        for period in periods:
+            if period == 'weekly':
+                # Resample to weekly timestamps
+                df = df.resample('1w').mean()
+                df['Date time'] = df.index
+
+            # Add bore specifics to dataframe
+            df['Site'] = site
+            df['Hole'] = hole
+            df['Pipe'] = pipe
+            df['Lat'] = lat
+            df['Lon'] = lon
+            df['Elev'] = elev
+            df['Basin'] = basin_id
+
+            master[period] = pd.concat([master[period], df])
 
         if clean_up:
             # Remove original zip archive
             os.remove(os.path.join(input_dir, zip_name))
+
+    for period in periods:
+        # Set column order
+        master[period] = master[period][[
+            'Date time', 'Basin', 'Site', 'Hole', 'Pipe',
+            'Below Measuring Point', 'Above Sea Level', 'Lat', 'Lon', 'Elev'
+        ]]
+
+        # Get latest date from dataframe
+        latest_date = master[period]['Date time'].iloc[-1].strftime('%Y-%m-%d')
+        csv_name = os.path.join(
+            output_dir, '{}-{}-{}.csv'.format(basin_id, latest_date, period))
+
+        # Export to csv
+        master[period].to_csv(csv_name, index=False, float_format='%0.3f')