--- a/water_cmd.c	Wed Mar 08 12:26:56 2006 +0000
+++ b/water_cmd.c	Wed Mar 08 13:03:29 2006 +0000
@@ -545,7 +545,7 @@
 				// Middle part of bridge with clear land below?
 				if ((_m[target].m5 & 0xF8) == 0xC0) {
 					_m[target].m5 |= 0x08;
-					MarkTileDirtyByTile(tile);
+					MarkTileDirtyByTile(target);
 				}
 				break;