diff -r e442ce398e83 -r d1ac22c62f64 src/tree_cmd.cpp
--- a/src/tree_cmd.cpp	Sun Aug 19 14:04:13 2007 +0000
+++ b/src/tree_cmd.cpp	Sun Sep 02 11:17:33 2007 +0000
@@ -255,6 +255,11 @@
 					cost.AddCost(_price.build_trees * 2);
 					break;
 
+				case MP_WATER:
+					msg = STR_3807_CAN_T_BUILD_ON_WATER;
+					continue;
+					break;
+
 				case MP_CLEAR:
 					if (!IsTileOwner(tile, OWNER_NONE) ||
 							IsBridgeAbove(tile)) {
@@ -656,6 +661,11 @@
 	_trees_tick_ctr = 0;
 }
 
+static CommandCost TerraformTile_Trees(TileIndex tile, uint32 flags, uint z_new, Slope tileh_new)
+{
+	return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+}
+
 
 extern const TileTypeProcs _tile_type_trees_procs = {
 	DrawTile_Trees,           /* draw_tile_proc */
@@ -671,4 +681,5 @@
 	NULL,                     /* get_produced_cargo_proc */
 	NULL,                     /* vehicle_enter_tile_proc */
 	GetFoundation_Trees,      /* get_foundation_proc */
+	TerraformTile_Trees,      /* terraform_tile_proc */
 };