--- a/src/newgrf_canal.h	Mon Dec 03 23:39:38 2007 +0000
+++ b/src/newgrf_canal.h	Tue Jan 22 21:00:30 2008 +0000
@@ -11,12 +11,21 @@
 	CF_DIKES,
 	CF_ICON,
 	CF_DOCKS,
+	CF_RIVER_SLOPE,
+	CF_RIVER_EDGE,
 	CF_END,
 };
 
 
+struct WaterFeature {
+	const SpriteGroup *group;
+	uint8 callbackmask;
+	uint8 flags;
+};
+
+
 /** Table of canal 'feature' sprite groups */
-extern const SpriteGroup *_canal_sg[CF_END];
+extern WaterFeature _water_feature[CF_END];
 
 
 /** Lookup the base sprite to use for a canal.