diff --git a/photogen.py b/photogen.py
index 7535edb..3792f4a 100644
--- a/photogen.py
+++ b/photogen.py
@@ -531,59 +531,61 @@ class mstr_photogen:
         # At ZL16 there seems to be an issue with water bodies, especially rivers (natural:water).
         # Let's see if we can correct that
 
-        # natural:water
-        ntrl_water = False
-        ntrl_idx = 0
-        for lyr in self._lyrnames:
-            if lyr[0] == "natural" and lyr[1] == "water":
-                ntrl_water = True
-                break
-            ntrl_idx = ntrl_idx + 1
+        # These files will need to be generated after manual check of the orthos
+        if os.path.isfile(mstr_datafolder + "z_orthographic/data" + self._latlngfld + "/water/" + str(self._ty) + "_" + str(self._tx)) == True:
+            # natural:water
+            ntrl_water = False
+            ntrl_idx = 0
+            for lyr in self._lyrnames:
+                if lyr[0] == "natural" and lyr[1] == "water":
+                    ntrl_water = True
+                    break
+                ntrl_idx = ntrl_idx + 1
 
-        if ntrl_water == True:
-            
-            # We'll go through all layers and "shavve off" excess.
-            # This way we can hopefully correct incorrect line and polygon renders.
-            for l in range(0, len(layers)):
-                if l < ntrl_idx: # <- We don't want to load the target layer itself
-                    lyrpix = layers[l].load()
-                    wtr_pix = layers[ntrl_idx].load()
-                    for y in range(0, self._tile.height):
-                        for x in range(0, self._tile.width):
-                            lp = lyrpix[x,y]
-                            wp = wtr_pix[x,y]
-                            if lp[3] > 0:
-                                a = 255 - lp[3]
-                                if a < wp[3]:
-                                    c = (wp[0], wp[1], wp[2], a)
-                                    wtr_pix[x,y] = c
+            if ntrl_water == True:
+                
+                # We'll go through all layers and "shavve off" excess.
+                # This way we can hopefully correct incorrect line and polygon renders.
+                for l in range(0, len(layers)):
+                    if l < ntrl_idx: # <- We don't want to load the target layer itself
+                        lyrpix = layers[l].load()
+                        wtr_pix = layers[ntrl_idx].load()
+                        for y in range(0, self._tile.height):
+                            for x in range(0, self._tile.width):
+                                lp = lyrpix[x,y]
+                                wp = wtr_pix[x,y]
+                                if lp[3] > 0:
+                                    a = 255 - lp[3]
+                                    if a < wp[3]:
+                                        c = (wp[0], wp[1], wp[2], a)
+                                        wtr_pix[x,y] = c
 
-        # water:river
-        river_water = False
-        river_idx = 0
-        for lyr in self._lyrnames:
-            if lyr[0] == "water" and lyr[1] == "river":
-                river_water = True
-                break
-            river_idx = river_idx + 1
+            # water:river
+            river_water = False
+            river_idx = 0
+            for lyr in self._lyrnames:
+                if lyr[0] == "water" and lyr[1] == "river":
+                    river_water = True
+                    break
+                river_idx = river_idx + 1
 
-        if river_water == True:
-            
-            # We'll go through all layers and "shavve off" excess.
-            # This way we can hopefully correct incorrect line and polygon renders.
-            for l in range(0, len(layers)):
-                if l < river_idx and l != ntrl_idx: # <- We don't want to load the target layer itself
-                    lyrpix = layers[l].load()
-                    wtr_pix = layers[river_idx].load()
-                    for y in range(0, self._tile.height):
-                        for x in range(0, self._tile.width):
-                            lp = lyrpix[x,y]
-                            wp = wtr_pix[x,y]
-                            if lp[3] > 0:
-                                a = 255 - lp[3]
-                                if a < wp[3]:
-                                    c = (wp[0], wp[1], wp[2], a)
-                                    wtr_pix[x,y] = c
+            if river_water == True:
+                
+                # We'll go through all layers and "shavve off" excess.
+                # This way we can hopefully correct incorrect line and polygon renders.
+                for l in range(0, len(layers)):
+                    if l < river_idx and l != ntrl_idx: # <- We don't want to load the target layer itself
+                        lyrpix = layers[l].load()
+                        wtr_pix = layers[river_idx].load()
+                        for y in range(0, self._tile.height):
+                            for x in range(0, self._tile.width):
+                                lp = lyrpix[x,y]
+                                wp = wtr_pix[x,y]
+                                if lp[3] > 0:
+                                    a = 255 - lp[3]
+                                    if a < wp[3]:
+                                        c = (wp[0], wp[1], wp[2], a)
+                                        wtr_pix[x,y] = c
 
         return layers