Fix openmaptiles/openmaptiles#78, Switch to OSM water bodies in z6

layers/water/README.md

@@ -7,5 +7,4 @@ Read the layer documentation at **http://openmaptiles.org/schema#water**
 ![Mapping diagram for water](http://openmaptiles.org/media/mapping_water.png)
 
 ### ETL diagram
-![ETL diagram for water](http://openmaptiles.org/media/etl_water.png)
-
+![ETL diagram for water](etl_diagram.png?raw=true)

layers/water/mapping.yaml

@@ -1,5 +1,11 @@
 generalized_tables:
 
+  # etldoc: imposm3 -> osm_water_polygon_gen6
+  water_polygon_gen6:
+    source: water_polygon_gen5
+    sql_filter: area>20000000.0
+    tolerance: 640.0
+
   # etldoc: imposm3 -> osm_water_polygon_gen5
   water_polygon_gen5:
     source: water_polygon_gen4

layers/water/water.sql

@@ -48,15 +48,15 @@ CREATE OR REPLACE VIEW water_z6 AS (
     -- etldoc:  ne_10m_ocean ->  water_z6
     SELECT geometry, 'ocean'::text AS class FROM ne_10m_ocean
     UNION ALL
-   -- etldoc:  ne_10m_lakes ->  water_z6    
-    SELECT geometry, 'lake'::text AS class FROM ne_10m_lakes
+   -- etldoc:  osm_water_polygon_gen6 ->  water_z6
+    SELECT geometry, 'lake' AS class FROM osm_water_polygon_gen6
 );
 
 CREATE OR REPLACE VIEW water_z7 AS (
     -- etldoc:  ne_10m_ocean ->  water_z7
     SELECT geometry, 'ocean'::text AS class FROM ne_10m_ocean
     UNION ALL
-    -- etldoc:  osm_water_polygon_gen3 ->  water_z7
+    -- etldoc:  osm_water_polygon_gen5 ->  water_z7
     SELECT geometry, 'lake' AS class FROM osm_water_polygon_gen5
 );
 
@@ -64,7 +64,7 @@ CREATE OR REPLACE VIEW water_z8 AS (
     -- etldoc:  ne_10m_ocean ->  water_z8
     SELECT geometry, 'ocean'::text AS class FROM ne_10m_ocean
     UNION ALL
-    -- etldoc:  osm_water_polygon_gen2 ->  water_z8         
+    -- etldoc:  osm_water_polygon_gen4 ->  water_z8
     SELECT geometry, 'lake' AS class FROM osm_water_polygon_gen4
 );
 
@@ -72,7 +72,7 @@ CREATE OR REPLACE VIEW water_z9 AS (
     -- etldoc:  osm_ocean_polygon_gen3 ->  water_z9
     SELECT geometry, 'ocean'::text AS class FROM osm_ocean_polygon_gen3
     UNION ALL
-    -- etldoc:  osm_water_polygon_gen1 ->  water_z9    
+    -- etldoc:  osm_water_polygon_gen3 ->  water_z9
     SELECT geometry, 'lake'::text AS class FROM osm_water_polygon_gen3
 );
 
@@ -88,7 +88,7 @@ CREATE OR REPLACE VIEW water_z11 AS (
     -- etldoc:  osm_ocean_polygon_gen1 ->  water_z11
     SELECT geometry, 'ocean'::text AS class FROM osm_ocean_polygon_gen1
     UNION ALL
-    -- etldoc:  osm_water_polygon ->  water_z11
+    -- etldoc:  osm_water_polygon_gen1 ->  water_z11
     SELECT geometry, water_class(waterway) AS class FROM osm_water_polygon_gen1 WHERE area > 40000
 );