diff --git a/layers/water/mapping.yaml b/layers/water/mapping.yaml
new file mode 100644
index 0000000..1fb3035
--- /dev/null
+++ b/layers/water/mapping.yaml
@@ -0,0 +1,67 @@
+generalized_tables:
+  water_polygon_gen3:
+    source: water_polygon
+    sql_filter: area>9000000.0
+    tolerance: 350.0
+  water_polygon_gen2:
+    source: water_polygon
+    sql_filter: area>1000000
+    tolerance: 200.0
+  water_polygon_gen1:
+    source: water_polygon
+    sql_filter: area>500000
+    tolerance: 100.0
+tables:
+  water_polygon:
+    fields:
+    - name: osm_id
+      type: id
+    - name: geometry
+      type: validated_geometry
+    - name: area
+      type: pseudoarea
+    - key: name
+      name: name
+      type: string
+    - name: name_en
+      key: name:en
+      type: string
+    filters:
+      exclude_tags:
+      - [ "covered", "yes" ]
+    mapping:
+      landuse:
+      - reservoir
+      natural:
+      - water
+      - bay
+      waterway:
+      - river
+      - riverbank
+      - stream
+      - canal
+      - drain
+      - ditch
+    type: polygon
+  water_linestring:
+    fields:
+    - name: osm_id
+      type: id
+    - name: geometry
+      type: geometry
+    - name: waterway
+      type: mapping_value
+    - key: name
+      name: name
+      type: string
+    - name: name_en
+      key: name:en
+      type: string
+    mapping:
+      waterway:
+      - stream
+      - river
+      - canal
+      - drain
+      - ditch
+    type: linestring
diff --git a/layers/water/water.sql b/layers/water/water.sql
index 079d030..7d66754 100644
--- a/layers/water/water.sql
+++ b/layers/water/water.sql
@@ -1,121 +1,115 @@
 CREATE OR REPLACE VIEW water_z0 AS (
-    SELECT geom FROM ne_110m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_110m_ocean
     UNION ALL
-    SELECT geom FROM ne_110m_lakes
+    SELECT geom, 'lake' AS class FROM ne_110m_lakes
 );
 
 CREATE OR REPLACE VIEW water_z1 AS (
-    SELECT geom FROM ne_110m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_110m_ocean
     UNION ALL
-    SELECT geom FROM ne_110m_lakes
+    SELECT geom, 'lake' AS class FROM ne_110m_lakes
 );
 
 CREATE OR REPLACE VIEW water_z2 AS (
-    SELECT geom FROM ne_50m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_50m_ocean
     UNION ALL
-    SELECT geom FROM ne_110m_lakes
+    SELECT geom, 'lake' AS class FROM ne_110m_lakes
 );
 
 CREATE OR REPLACE VIEW water_z3 AS (
-    SELECT geom FROM ne_50m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_50m_ocean
     UNION ALL
-    SELECT geom FROM ne_110m_lakes
+    SELECT geom, 'lake' AS class FROM ne_110m_lakes
     UNION ALL
-    SELECT geom FROM ne_110m_rivers_lake_centerlines
+    SELECT geom, 'river' AS class FROM ne_110m_rivers_lake_centerlines
     WHERE featurecla = 'River'
 );
 
 CREATE OR REPLACE VIEW water_z4 AS (
-    SELECT geom FROM ne_50m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_50m_ocean
     UNION ALL
-    SELECT geom FROM ne_50m_lakes
+    SELECT geom, 'lake' AS class FROM ne_50m_lakes
     UNION ALL
-    SELECT geom FROM ne_50m_rivers_lake_centerlines
+    SELECT geom, 'river' AS class FROM ne_50m_rivers_lake_centerlines
     WHERE featurecla = 'River'
 );
 
 CREATE OR REPLACE VIEW water_z5 AS (
-    SELECT geom FROM ne_10m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_10m_ocean
     UNION ALL
-    SELECT geom FROM ne_10m_lakes
+    SELECT geom, 'lake' AS class FROM ne_10m_lakes
     UNION ALL
-    SELECT geom FROM ne_50m_rivers_lake_centerlines
+    SELECT geom, 'river' AS class FROM ne_50m_rivers_lake_centerlines
     WHERE featurecla = 'River'
 );
 
 CREATE OR REPLACE VIEW water_z6 AS (
-    SELECT geom FROM ne_10m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_10m_ocean
     UNION ALL
-    SELECT geom FROM ne_10m_lakes
+    SELECT geom, 'lake' AS class FROM ne_10m_lakes
     UNION ALL
-    SELECT geom FROM ne_10m_rivers_lake_centerlines
+    SELECT geom, 'river' AS class FROM ne_10m_rivers_lake_centerlines
     WHERE featurecla = 'River'
 );
 
 CREATE TABLE IF NOT EXISTS water_z7 AS (
-    SELECT geom FROM ne_10m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_10m_ocean
     UNION ALL
-    SELECT ST_SimplifyPreserveTopology(way, 350) AS geom FROM water_areas
-    WHERE way_area > 9000000
+    SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon_gen3
     UNION ALL
-    SELECT geom FROM ne_10m_rivers_lake_centerlines
+    SELECT geom, 'river' AS class FROM ne_10m_rivers_lake_centerlines
     WHERE featurecla = 'River'
 );
 CREATE INDEX IF NOT EXISTS water_z7_geom_idx ON water_z7 USING gist(geom);
 
 CREATE TABLE IF NOT EXISTS water_z8 AS (
-    SELECT geom FROM ne_10m_ocean
+    SELECT geom, 'ocean' AS class FROM ne_10m_ocean
     UNION ALL
-    SELECT ST_SimplifyPreserveTopology(way, 200) AS geom FROM water_areas
-    WHERE way_area > 1000000
+    SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon_gen2
     UNION ALL
-    SELECT ST_Simplify(way, 200) AS geom FROM waterways
-    WHERE waterway IN ('river') AND ST_Length(way) > 10000
+    SELECT ST_Simplify(geometry, 200) AS geom, waterway AS class FROM osm_water_linestring
+    WHERE waterway IN ('river') AND ST_Length(geometry) > 10000
 );
 CREATE INDEX IF NOT EXISTS water_z8_geom_idx ON water_z8 USING gist(geom);
 
 CREATE TABLE IF NOT EXISTS water_z9 AS (
-    SELECT ST_SimplifyPreserveTopology(way, 100) AS geom FROM water_areas
-    WHERE way_area > 500000
+    SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon_gen1
     UNION ALL
-    SELECT ST_Simplify(way,100) AS geom FROM waterways
-    WHERE waterway IN ('river') AND ST_Length(way) > 5000
+    SELECT ST_Simplify(geometry, 100) AS geom, waterway AS class FROM osm_water_linestring
+    WHERE waterway IN ('river') AND ST_Length(geometry) > 5000
 );
 CREATE INDEX IF NOT EXISTS water_z9_geom_idx ON water_z9 USING gist(geom);
 
 CREATE OR REPLACE VIEW water_z11 AS (
-    SELECT way AS geom FROM water_areas
-    WHERE way_area > 50000
+    SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon WHERE area > 40000
     UNION ALL
-    SELECT way AS geom FROM waterways
-    WHERE waterway IN ('river')
+    SELECT geometry AS geom, waterway AS class FROM osm_water_linestring
+    WHERE waterway IN ('river') AND ST_Length(geometry) > 5000
 );
 
 CREATE OR REPLACE VIEW water_z12 AS (
-    SELECT way AS geom FROM water_areas
-    WHERE way_area > 40000
+    SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon WHERE area > 10000
     UNION ALL
-    SELECT way AS geom FROM waterways
-    WHERE waterway IN ('river', 'canal', 'stream')
+    SELECT geometry AS geom, waterway AS class FROM osm_water_linestring
+    WHERE waterway IN ('river', 'canal') OR (waterway = 'stream' AND ST_Length(geometry) > 1000)
 );
 
 CREATE OR REPLACE VIEW water_z13 AS (
-    SELECT way AS geom FROM water_areas
-    WHERE way_area > 2000
+    SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon WHERE area > 5000
     UNION ALL
-    SELECT way AS geom FROM waterways
-    WHERE waterway IN ('river', 'canal', 'stream', 'drain', 'ditch')
+    SELECT geometry AS geom, waterway AS class FROM osm_water_linestring
+    WHERE waterway IN ('river', 'canal', 'stream', 'drain', 'ditch') AND ST_Length(geometry) > 300
 );
 
 CREATE OR REPLACE VIEW water_z14 AS (
-    SELECT way AS geom FROM water_areas
+    SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon
     UNION ALL
-    SELECT way AS geom FROM waterways
+    SELECT geometry AS geom, waterway AS class FROM osm_water_linestring
 );
 
 CREATE OR REPLACE FUNCTION layer_water (bbox geometry, zoom_level int)
-RETURNS TABLE(geom geometry) AS $$
-    SELECT geom FROM (
+RETURNS TABLE(geom geometry, class text) AS $$
+    SELECT geom, class FROM (
         SELECT * FROM water_z0 WHERE zoom_level = 0
         UNION ALL
         SELECT * FROM water_z1 WHERE zoom_level = 1
@@ -132,9 +126,9 @@ RETURNS TABLE(geom geometry) AS $$
         UNION ALL
         SELECT * FROM water_z7 WHERE zoom_level = 7
         UNION ALL
-        SELECT geom FROM water_z8 WHERE zoom_level = 8
+        SELECT * FROM water_z8 WHERE zoom_level = 8
         UNION ALL
-        SELECT geom FROM water_z9 WHERE zoom_level BETWEEN 9 AND 10
+        SELECT * FROM water_z9 WHERE zoom_level BETWEEN 9 AND 10
         UNION ALL
         SELECT * FROM water_z11 WHERE zoom_level = 11
         UNION ALL
diff --git a/layers/water/water.yaml b/layers/water/water.yaml
index ce2dd96..e343aaa 100644
--- a/layers/water/water.yaml
+++ b/layers/water/water.yaml
@@ -1,8 +1,12 @@
 layer:
   id: "water"
-  description: water
+  description: |
+      Water polygons and linestrings representing oceans, lakes and waterways.
   buffer_size: 4
   datasource:
     query: (SELECT * FROM layer_water(!bbox!, z(!scale_denominator!))) AS t
 schema:
   - ./water.sql
+datasources:
+  - type: imposm3
+    mapping_file: ./mapping.yaml