diff --git a/src/interface/viewport.c b/src/interface/viewport.c
index 35d60909ee..41cb43ed47 100644
--- a/src/interface/viewport.c
+++ b/src/interface/viewport.c
@@ -1955,7 +1955,7 @@ void sub_68862C()
  * mapElement: edx
  * viewport: edi
  */
-void get_map_coordinates_from_pos(int screenX, int screenY, int flags, int *x, int *y, int *interactionType, rct_map_element **mapElement, rct_viewport **viewport)
+void get_map_coordinates_from_pos(int screenX, int screenY, int flags, sint16 *x, sint16 *y, int *interactionType, rct_map_element **mapElement, rct_viewport **viewport)
 {
 	RCT2_GLOBAL(0x9AC154, uint16_t) = flags & 0xFFFF;
 	RCT2_GLOBAL(0x9AC148, uint8_t) = 0;
@@ -1994,7 +1994,7 @@ void get_map_coordinates_from_pos(int screenX, int screenY, int flags, int *x, i
 		if (viewport != NULL) *viewport = myviewport;
 	}
 	if (interactionType != NULL) *interactionType = RCT2_GLOBAL(0x9AC148, uint8_t);
-	if (x != NULL) *x = (int)RCT2_GLOBAL(0x9AC14C, int16_t);
-	if (y != NULL) *y = (int)RCT2_GLOBAL(0x9AC14E, int16_t);
+	if (x != NULL) *x = RCT2_GLOBAL(0x9AC14C, int16_t);
+	if (y != NULL) *y = RCT2_GLOBAL(0x9AC14E, int16_t);
 	if (mapElement != NULL) *mapElement = RCT2_GLOBAL(0x9AC150, rct_map_element*);
 }
\ No newline at end of file
diff --git a/src/windows/top_toolbar.c b/src/windows/top_toolbar.c
index 5167793671..490c6c6eca 100644
--- a/src/windows/top_toolbar.c
+++ b/src/windows/top_toolbar.c
@@ -1792,6 +1792,140 @@ void top_toolbar_tool_update_land(sint16 x, sint16 y){
 	}
 }
 
+/**
+*
+*  rct2: 0x006E6BDC
+*/
+void top_toolbar_tool_update_water(sint16 x, sint16 y){
+	map_invalidate_selection_rect();
+
+	if (RCT2_GLOBAL(RCT2_ADDRESS_CURRENT_TOOL, uint8) == 3){
+		if (!(RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_FLAGS, uint16) & (1 << 0)))
+			return;
+
+		money32 lower_cost = lower_water(
+			RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_X, sint16),
+			RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_Y, sint16),
+			RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_X, sint16),
+			RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_Y, sint16),
+			0);
+
+		money32 raise_cost = raise_water(
+			RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_X, sint16),
+			RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_Y, sint16),
+			RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_X, sint16),
+			RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_Y, sint16),
+			0);
+
+		if (RCT2_GLOBAL(RCT2_ADDRESS_WATER_RAISE_COST, money32) != raise_cost ||
+			RCT2_GLOBAL(RCT2_ADDRESS_WATER_LOWER_COST, money32) != lower_cost){
+			RCT2_GLOBAL(RCT2_ADDRESS_WATER_RAISE_COST, money32) = raise_cost;
+			RCT2_GLOBAL(RCT2_ADDRESS_WATER_LOWER_COST, money32) = lower_cost;
+			window_invalidate_by_class(WC_WATER);
+		}
+		return;
+	}
+
+	RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_FLAGS, uint16) &= ~(1 << 0);
+
+	rct_xy16 mapTile = { 0 };
+	int interaction_type = 0;
+	get_map_coordinates_from_pos(
+		x, 
+		y, 
+		VIEWPORT_INTERACTION_MASK_TERRAIN & VIEWPORT_INTERACTION_MASK_WATER, 
+		&mapTile.x, 
+		&mapTile.y, 
+		&interaction_type,
+		NULL,
+		NULL);
+
+	if (interaction_type == VIEWPORT_INTERACTION_ITEM_NONE){
+		if (RCT2_GLOBAL(RCT2_ADDRESS_WATER_RAISE_COST, money32) != MONEY32_UNDEFINED ||
+			RCT2_GLOBAL(RCT2_ADDRESS_WATER_LOWER_COST, money32) != MONEY32_UNDEFINED){
+			RCT2_GLOBAL(RCT2_ADDRESS_WATER_RAISE_COST, money32) = MONEY32_UNDEFINED;
+			RCT2_GLOBAL(RCT2_ADDRESS_WATER_LOWER_COST, money32) = MONEY32_UNDEFINED;
+			window_invalidate_by_class(WC_WATER);
+		}
+		return;
+	}
+
+	mapTile.x += 16;
+	mapTile.y += 16;
+
+	uint8 state_changed = 0;
+
+	if (!(RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_FLAGS, uint16) & (1 << 0))){
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_FLAGS, uint16) |= (1 << 0);
+		state_changed++;
+	}
+
+	if (RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_TYPE, uint16) != 4){
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_TYPE, uint16) = 4;
+		state_changed++;
+	}
+
+	sint16 tool_size = RCT2_GLOBAL(RCT2_ADDRESS_LAND_TOOL_SIZE, sint16);
+	if (tool_size == 0)
+		tool_size = 1;
+
+	sint16 tool_length = (tool_size - 1) * 32;
+
+	// Move to tool bottom left
+	mapTile.x -= (tool_size - 1) * 16;
+	mapTile.y -= (tool_size - 1) * 16;
+	mapTile.x &= 0xFFE0;
+	mapTile.y &= 0xFFE0;
+
+	if (RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_X, sint16) != mapTile.x){
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_X, sint16) = mapTile.x;
+		state_changed++;
+	}
+
+	if (RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_Y, sint16) != mapTile.y){
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_Y, sint16) = mapTile.y;
+		state_changed++;
+	}
+
+	mapTile.x += tool_length;
+	mapTile.y += tool_length;
+
+	if (RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_X, sint16) != mapTile.x){
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_X, sint16) = mapTile.x;
+		state_changed++;
+	}
+
+	if (RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_Y, sint16) != mapTile.y){
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_Y, sint16) = mapTile.y;
+		state_changed++;
+	}
+
+	map_invalidate_selection_rect();
+	if (!state_changed)
+		return;
+
+	money32 lower_cost = lower_water(
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_X, sint16),
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_Y, sint16),
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_X, sint16),
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_Y, sint16),
+		0);
+
+	money32 raise_cost = raise_water(
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_X, sint16),
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_A_Y, sint16),
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_X, sint16),
+		RCT2_GLOBAL(RCT2_ADDRESS_MAP_SELECTION_B_Y, sint16),
+		0);
+
+	if (RCT2_GLOBAL(RCT2_ADDRESS_WATER_RAISE_COST, money32) != raise_cost ||
+		RCT2_GLOBAL(RCT2_ADDRESS_WATER_LOWER_COST, money32) != lower_cost){
+		RCT2_GLOBAL(RCT2_ADDRESS_WATER_RAISE_COST, money32) = raise_cost;
+		RCT2_GLOBAL(RCT2_ADDRESS_WATER_LOWER_COST, money32) = lower_cost;
+		window_invalidate_by_class(WC_WATER);
+	}
+}
+
 /**
  *
  *  rct2: 0x0066CB25
diff --git a/src/world/map.c b/src/world/map.c
index c84d6248a0..7086d14a7f 100644
--- a/src/world/map.c
+++ b/src/world/map.c
@@ -1560,68 +1560,59 @@ void game_command_lower_land(int* eax, int* ebx, int* ecx, int* edx, int* esi, i
 	*ebx = cost;
 }
 
-/**
- *
- *  rct2: 0x006E66A0
- */
-void game_command_raise_water(int* eax, int* ebx, int* ecx, int* edx, int* esi, int* edi, int* ebp)
-{
-	int ax = (uint16)*eax;
-	int ay = (uint16)*ecx;
-	int bx = (uint16)*edi;
-	int by = (uint16)*ebp;
-
-	int cost = 0;
+money32 raise_water(sint16 x0, sint16 y0, sint16 x1, sint16 y1, uint8 flags){
+	money32 cost = 0;
 
 	uint8 max_height = 0xFF;
 
-	for(int yi = ay; yi <= by; yi += 32){
-		for(int xi = ax; xi <= bx; xi += 32){
+	for (int yi = y0; yi <= y1; yi += 32){
+		for (int xi = x0; xi <= x1; xi += 32){
 			rct_map_element* map_element = map_get_surface_element_at(xi / 32, yi / 32);
 			uint8 height = map_element->base_height;
-			if(map_element->properties.surface.terrain & 0x1F){
+			if (map_element->properties.surface.terrain & 0x1F){
 				height = (map_element->properties.surface.terrain & 0x1F) * 2;
 			}
-			if(max_height > height){
+			if (max_height > height){
 				max_height = height;
 			}
 		}
 	}
 
-	for(int yi = ay; yi <= by; yi += 32){
-		for(int xi = ax; xi <= bx; xi += 32){
+	for (int yi = y0; yi <= y1; yi += 32){
+		for (int xi = x0; xi <= x1; xi += 32){
 			rct_map_element* map_element = map_get_surface_element_at(xi / 32, yi / 32);
-			
-			if(map_element->base_height <= max_height){
+
+			if (map_element->base_height <= max_height){
 				uint8 height = (map_element->properties.surface.terrain & 0x1F);
-				if(height){
+				if (height){
 					height *= 2;
-					if(height > max_height){
+					if (height > max_height){
 						continue;
 					}
 					height += 2;
-				}else{
+				}
+				else{
 					height = map_element->base_height + 2;
 				}
-				int eax2 = xi, ebx2 = *ebx, ecx2 = yi, edx2 = (max_height << 8) + height, esi2, edi2, ebp2;
-				ebx2 = game_do_command_p(GAME_COMMAND_16, &eax2, &ebx2, &ecx2, &edx2, &esi2, &edi2, &ebp2);
-				if(ebx2 == MONEY32_UNDEFINED){
-					*ebx = MONEY32_UNDEFINED;
-					return;
-				}else{
-					cost += ebx2;
+
+				money32 cost2 = game_do_command(GAME_COMMAND_16, xi, flags, yi, (max_height << 8) + height, 0, 0, 0);
+				if (cost2 == MONEY32_UNDEFINED){
+					return MONEY32_UNDEFINED;
+				}
+				else{
+					cost += cost2;
 				}
 			}
 		}
 	}
-	if(*ebx & GAME_COMMAND_FLAG_APPLY){
-		int x = ((ax + bx) / 2) + 16;
-		int y = ((ay + by) / 2) + 16;
+	if (flags & GAME_COMMAND_FLAG_APPLY){
+		int x = ((x0 + x1) / 2) + 16;
+		int y = ((y0 + y1) / 2) + 16;
 		int z = map_element_height(x, y);
 		sint16 water_height_z = z >> 16;
 		sint16 base_height_z = z;
 		z = water_height_z;
-		if(!z){
+		if (!z){
 			z = base_height_z;
 		}
 		RCT2_GLOBAL(0x009DEA5E, uint32) = x;
@@ -1629,7 +1620,79 @@ void game_command_raise_water(int* eax, int* ebx, int* ecx, int* edx, int* esi,
 		RCT2_GLOBAL(0x009DEA62, uint32) = z;
 		sound_play_panned(SOUND_LAYING_OUT_WATER, 0x8001, x, y, z);
 	}
-	*ebx = cost;
+	return cost;
+}
+
+/**
+ *
+ *  rct2: 0x006E66A0
+ */
+void game_command_raise_water(int* eax, int* ebx, int* ecx, int* edx, int* esi, int* edi, int* ebp)
+{
+	*ebx = raise_water(
+		(sint16)*eax,
+		(sint16)*ecx,
+		(sint16)*edi,
+		(sint16)*ebp,
+		(uint8)*ebx);
+}
+
+money32 lower_water(sint16 x0, sint16 y0, sint16 x1, sint16 y1, uint8 flags){
+	money32 cost = 0;
+
+	uint8 min_height = 0;
+
+	for (int yi = y0; yi <= y1; yi += 32){
+		for (int xi = x0; xi <= x1; xi += 32){
+			rct_map_element* map_element = map_get_surface_element_at(xi / 32, yi / 32);
+
+			uint8 height = map_element->properties.surface.terrain & 0x1F;
+			if (height){
+				height *= 2;
+				if (height > min_height){
+					min_height = height;
+				}
+			}
+		}
+	}
+
+	for (int yi = y0; yi <= y1; yi += 32){
+		for (int xi = x0; xi <= x1; xi += 32){
+			rct_map_element* map_element = map_get_surface_element_at(xi / 32, yi / 32);
+
+			uint8 height = (map_element->properties.surface.terrain & 0x1F);
+			if (height){
+				height *= 2;
+				if (height < min_height){
+					continue;
+				}
+				height -= 2;
+				int cost2 = game_do_command(xi, flags, yi, (min_height << 8) + height, GAME_COMMAND_16, 0, 0);
+				if (cost2 == MONEY32_UNDEFINED){
+					return MONEY32_UNDEFINED;
+				}
+				else{
+					cost += cost2;
+				}
+			}
+		}
+	}
+	if (flags & GAME_COMMAND_FLAG_APPLY){
+		int x = ((x0 + x1) / 2) + 16;
+		int y = ((y0 + y1) / 2) + 16;
+		int z = map_element_height(x, y);
+		sint16 water_height_z = z >> 16;
+		sint16 base_height_z = z;
+		z = water_height_z;
+		if (!z){
+			z = base_height_z;
+		}
+		RCT2_GLOBAL(0x009DEA5E, uint32) = x;
+		RCT2_GLOBAL(0x009DEA60, uint32) = y;
+		RCT2_GLOBAL(0x009DEA62, uint32) = z;
+		sound_play_panned(SOUND_LAYING_OUT_WATER, 0x8001, x, y, z);
+	}
+	return cost;
 }
 
 /**
@@ -1638,66 +1701,12 @@ void game_command_raise_water(int* eax, int* ebx, int* ecx, int* edx, int* esi,
  */
 void game_command_lower_water(int* eax, int* ebx, int* ecx, int* edx, int* esi, int* edi, int* ebp)
 {
-	int ax = (uint16)*eax;
-	int ay = (uint16)*ecx;
-	int bx = (uint16)*edi;
-	int by = (uint16)*ebp;
-
-	int cost = 0;
-
-	uint8 min_height = 0;
-
-	for(int yi = ay; yi <= by; yi += 32){
-		for(int xi = ax; xi <= bx; xi += 32){
-			rct_map_element* map_element = map_get_surface_element_at(xi / 32, yi / 32);
-
-			uint8 height = map_element->properties.surface.terrain & 0x1F;
-			if(height){
-				height *= 2;
-				if(height > min_height){
-					min_height = height;
-				}
-			}
-		}
-	}
-
-	for(int yi = ay; yi <= by; yi += 32){
-		for(int xi = ax; xi <= bx; xi += 32){
-			rct_map_element* map_element = map_get_surface_element_at(xi / 32, yi / 32);
-			
-			uint8 height = (map_element->properties.surface.terrain & 0x1F);
-			if(height){
-				height *= 2;
-				if(height < min_height){
-					continue;
-				}
-				height -= 2;
-				int ebx2 = game_do_command(xi, *ebx, yi, (min_height << 8) + height, GAME_COMMAND_16, 0, 0);
-				if(ebx2 == MONEY32_UNDEFINED){
-					*ebx = MONEY32_UNDEFINED;
-					return;
-				}else{
-					cost += ebx2;
-				}
-			}
-		}
-	}
-	if(*ebx & GAME_COMMAND_FLAG_APPLY){
-		int x = ((ax + bx) / 2) + 16;
-		int y = ((ay + by) / 2) + 16;
-		int z = map_element_height(x, y);
-		sint16 water_height_z = z >> 16;
-		sint16 base_height_z = z;
-		z = water_height_z;
-		if(!z){
-			z = base_height_z;
-		}
-		RCT2_GLOBAL(0x009DEA5E, uint32) = x;
-		RCT2_GLOBAL(0x009DEA60, uint32) = y;
-		RCT2_GLOBAL(0x009DEA62, uint32) = z;
-		sound_play_panned(SOUND_LAYING_OUT_WATER, 0x8001, x, y, z);
-	}
-	*ebx = cost;
+	*ebx = lower_water(
+		(sint16)*eax, 
+		(sint16)*ecx, 
+		(sint16)*edi, 
+		(sint16)*ebp, 
+		(uint8)*ebx);
 }
 
 /**
diff --git a/src/world/map.h b/src/world/map.h
index 89d65937df..f978ed971b 100644
--- a/src/world/map.h
+++ b/src/world/map.h
@@ -280,6 +280,8 @@ int map_can_construct_with_clear_at(int x, int y, int zLow, int zHigh, void *cle
 int map_can_construct_at(int x, int y, int zLow, int zHigh, uint8 bl);
 int sub_6BA278(int ebx);
 money32 map_clear_scenery(int x0, int y0, int x1, int y1, int flags);
+money32 lower_water(sint16 x0, sint16 y0, sint16 x1, sint16 y1, uint8 flags);
+money32 raise_water(sint16 x0, sint16 y0, sint16 x1, sint16 y1, uint8 flags);
 
 void game_command_remove_scenery(int* eax, int* ebx, int* ecx, int* edx, int* esi, int* edi, int* ebp);
 void game_command_remove_large_scenery(int* eax, int* ebx, int* ecx, int* edx, int* esi, int* edi, int* ebp);