Index: src/water_cmd.cpp
===================================================================
--- src/water_cmd.cpp	(revision 27196)
+++ src/water_cmd.cpp	(working copy)
@@ -123,6 +123,8 @@
 	CommandCost cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_DEPOT_SHIP]);
 
 	bool add_cost = !IsWaterTile(tile);
+	bool river1 = HasBit(_me[tile].m6, 0);
+	bool river2 = HasBit(_me[tile2].m6, 0);
 	CommandCost ret = DoCommand(tile, 0, 0, flags | DC_AUTO, CMD_LANDSCAPE_CLEAR);
 	if (ret.Failed()) return ret;
 	if (add_cost) {
@@ -145,7 +147,8 @@
 		}
 		Company::Get(_current_company)->infrastructure.water += 2 * LOCK_DEPOT_TILE_FACTOR;
 		DirtyCompanyInfrastructureWindows(_current_company);
-
+		if (river1) SB(_me[tile].m6, 0, 1, 1);
+		if (river2) SB(_me[tile2].m6, 0, 1, 1);
 		MakeShipDepot(tile,  _current_company, depot->index, DEPOT_PART_NORTH, axis, wc1);
 		MakeShipDepot(tile2, _current_company, depot->index, DEPOT_PART_SOUTH, axis, wc2);
 		MarkTileDirtyByTile(tile);
@@ -209,13 +212,16 @@
 
 static CommandCost RemoveShipDepot(TileIndex tile, DoCommandFlag flags)
 {
+	TileIndex tile2 = GetOtherShipDepotTile(tile);
+	bool river1 = HasBit(_me[tile].m6, 0);
+	bool river2 = HasBit(_me[tile2].m6, 0);
 	if (!IsShipDepot(tile)) return CMD_ERROR;
 
 	CommandCost ret = CheckTileOwnership(tile);
 	if (ret.Failed()) return ret;
 
-	TileIndex tile2 = GetOtherShipDepotTile(tile);
 
+
 	/* do not check for ship on tile when company goes bankrupt */
 	if (!(flags & DC_BANKRUPT)) {
 		CommandCost ret = EnsureNoVehicleOnGround(tile);
@@ -231,7 +237,8 @@
 			c->infrastructure.water -= 2 * LOCK_DEPOT_TILE_FACTOR;
 			DirtyCompanyInfrastructureWindows(c->index);
 		}
-
+		if (river1) SB(_me[tile].m6, 0, 1, 1);
+		if (river2) SB(_me[tile2].m6, 0, 1, 1);
 		MakeWaterKeepingClass(tile,  GetTileOwner(tile));
 		MakeWaterKeepingClass(tile2, GetTileOwner(tile2));
 	}
@@ -264,7 +271,7 @@
 
 	/* lower tile */
 	WaterClass wc_lower = IsWaterTile(tile - delta) ? GetWaterClass(tile - delta) : WATER_CLASS_CANAL;
-
+	
 	if (!IsWaterTile(tile - delta)) {
 		ret = DoCommand(tile - delta, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 		if (ret.Failed()) return ret;
@@ -277,7 +284,7 @@
 
 	/* upper tile */
 	WaterClass wc_upper = IsWaterTile(tile + delta) ? GetWaterClass(tile + delta) : WATER_CLASS_CANAL;
-
+	
 	if (!IsWaterTile(tile + delta)) {
 		ret = DoCommand(tile + delta, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 		if (ret.Failed()) return ret;
@@ -291,7 +298,8 @@
 	if (IsBridgeAbove(tile) || IsBridgeAbove(tile - delta) || IsBridgeAbove(tile + delta)) {
 		return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
 	}
-
+	bool river_lower = HasBit(_me[tile - delta].m6, 0);
+	bool river_upper = HasBit(_me[tile + delta].m6, 0);
 	if (flags & DC_EXEC) {
 		/* Update company infrastructure counts. */
 		Company *c = Company::GetIfValid(_current_company);
@@ -303,7 +311,8 @@
 			c->infrastructure.water += 3 * LOCK_DEPOT_TILE_FACTOR; // Lock is three tiles.
 			DirtyCompanyInfrastructureWindows(_current_company);
 		}
-
+		if (river_lower) SB(_me[tile - delta].m6, 0, 1, 1);
+		if (river_upper) SB(_me[tile + delta].m6, 0, 1, 1);
 		MakeLock(tile, _current_company, dir, wc_lower, wc_upper, wc_middle);
 		MarkTileDirtyByTile(tile);
 		MarkTileDirtyByTile(tile - delta);
@@ -336,7 +345,8 @@
 	if (ret.Succeeded()) ret = EnsureNoVehicleOnGround(tile + delta);
 	if (ret.Succeeded()) ret = EnsureNoVehicleOnGround(tile - delta);
 	if (ret.Failed()) return ret;
-
+	bool river_lower = HasBit(_me[tile - delta].m6, 0);
+	bool river_upper = HasBit(_me[tile + delta].m6, 0);
 	if (flags & DC_EXEC) {
 		/* Remove middle part from company infrastructure count. */
 		Company *c = Company::GetIfValid(GetTileOwner(tile));
@@ -352,6 +362,8 @@
 		}
 		MakeWaterKeepingClass(tile + delta, GetTileOwner(tile + delta));
 		MakeWaterKeepingClass(tile - delta, GetTileOwner(tile - delta));
+		if (river_lower) SB(_me[tile - delta].m6, 0, 1, 1);
+		if (river_upper) SB(_me[tile + delta].m6, 0, 1, 1);
 		MarkCanalsAndRiversAroundDirty(tile);
 		MarkCanalsAndRiversAroundDirty(tile - delta);
 		MarkCanalsAndRiversAroundDirty(tile + delta);
@@ -419,6 +431,7 @@
 		if (IsTileType(tile, MP_WATER) && (!IsTileOwner(tile, OWNER_WATER) || wc == WATER_CLASS_SEA)) continue;
 
 		bool water = IsWaterTile(tile);
+		bool river = HasTileWaterClass(tile) && GetWaterClass(tile) == WATER_CLASS_RIVER;
 		ret = DoCommand(tile, 0, 0, flags | DC_FORCE_CLEAR_TILE, CMD_LANDSCAPE_CLEAR);
 		if (ret.Failed()) return ret;
 
@@ -442,6 +455,7 @@
 					/* FALL THROUGH */
 
 				default:
+					if (river) SB(_me[tile].m6, 0, 1, 1);
 					MakeCanal(tile, _current_company, Random());
 					if (Company::IsValidID(_current_company)) {
 						Company::Get(_current_company)->infrastructure.water++;
@@ -465,6 +479,7 @@
 
 static CommandCost ClearTile_Water(TileIndex tile, DoCommandFlag flags)
 {
+	bool river = HasBit(_me[tile].m6, 0);
 	switch (GetWaterTileType(tile)) {
 		case WATER_TILE_CLEAR: {
 			if (flags & DC_NO_WATER) return_cmd_error(STR_ERROR_CAN_T_BUILD_ON_WATER);
@@ -485,7 +500,6 @@
 				CommandCost ret = CheckTileOwnership(tile);
 				if (ret.Failed()) return ret;
 			}
-
 			if (flags & DC_EXEC) {
 				if (IsCanal(tile) && Company::IsValidID(owner)) {
 					Company::Get(owner)->infrastructure.water--;
@@ -492,9 +506,9 @@
 					DirtyCompanyInfrastructureWindows(owner);
 				}
 				DoClearSquare(tile);
+				if (river) MakeRiver(tile, Random());
 				MarkCanalsAndRiversAroundDirty(tile);
 			}
-
 			return CommandCost(EXPENSES_CONSTRUCTION, base_cost);
 		}