--- a/water_cmd.c	Fri Jun 30 18:06:44 2006 +0000
+++ b/water_cmd.c	Fri Jun 30 20:16:14 2006 +0000
@@ -654,7 +654,8 @@
 	};
 
 	/* Ensure sea-level canals do not flood */
-	if (IsTileType(tile, MP_WATER) && !IsTileOwner(tile, OWNER_WATER)) return;
+	if ((IsTileType(tile, MP_WATER) || IsTileType(tile, MP_TUNNELBRIDGE)) &&
+			!IsTileOwner(tile, OWNER_WATER)) return;
 
 	if (IS_INT_INSIDE(TileX(tile), 1, MapSizeX() - 3 + 1) &&
 			IS_INT_INSIDE(TileY(tile), 1, MapSizeY() - 3 + 1)) {