Index: src/water_cmd.cpp
===================================================================
--- src/water_cmd.cpp	(revision 27196)
+++ src/water_cmd.cpp	(working copy)
@@ -419,6 +419,7 @@
 		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 +443,7 @@
 					/* FALL THROUGH */
 
 				default:
+					if (river) SB(_me[tile].m6, 0, 0, 1);
 					MakeCanal(tile, _current_company, Random());
 					if (Company::IsValidID(_current_company)) {
 						Company::Get(_current_company)->infrastructure.water++;
@@ -485,7 +487,7 @@
 				CommandCost ret = CheckTileOwnership(tile);
 				if (ret.Failed()) return ret;
 			}
-
+			bool river = HasBit(_me[tile].m6, 0);
 			if (flags & DC_EXEC) {
 				if (IsCanal(tile) && Company::IsValidID(owner)) {
 					Company::Get(owner)->infrastructure.water--;
@@ -492,9 +494,9 @@
 					DirtyCompanyInfrastructureWindows(owner);
 				}
 				DoClearSquare(tile);
+				if (river) MakeRiver(tile, Random());
 				MarkCanalsAndRiversAroundDirty(tile);
 			}
-
 			return CommandCost(EXPENSES_CONSTRUCTION, base_cost);
 		}