diff --git a/Makefile b/Makefile
index 3e63fa3b..8ff02da4 100644
--- a/Makefile
+++ b/Makefile
@@ -10,4 +10,4 @@ build/tileset.sql:
 	mkdir -p build && generate-sql openmaptiles.yaml > build/tileset.sql
 
 clean:
-	rm -rf build
+	rm -f build/openmaptiles.tm2source/data.yml && rm -f build/mapping.yaml && rm -f build/tileset.sql
diff --git a/README.md b/README.md
index 4619c1ec..60cd000e 100644
--- a/README.md
+++ b/README.md
@@ -92,7 +92,7 @@ docker-compose run import-sql
 ```
 
 To look at the vector tiles you can start up Mapbox Studio Classic in a container
-and visit `localhost:3000` and open the vector source project under `projects/osm2vectortiles.tm2source`.
+and visit `localhost:3000` and open the vector source project under `/projects`.
 
 ```bash
 docker-compose up mapbox-studio
diff --git a/docker-compose.yml b/docker-compose.yml
index 85e3e85b..e5c27cea 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -22,6 +22,8 @@ services:
   import-osm:
     image: "openmaptiles/import-osm"
     env_file: .env
+    environment:
+      DIFF_MODE: "false"
     links:
     - postgres
     volumes:
diff --git a/layers/water/water.sql b/layers/water/water.sql
index 7d66754b..c0dc0acd 100644
--- a/layers/water/water.sql
+++ b/layers/water/water.sql
@@ -16,49 +16,28 @@ CREATE OR REPLACE VIEW water_z2 AS (
     SELECT geom, 'lake' AS class FROM ne_110m_lakes
 );
 
-CREATE OR REPLACE VIEW water_z3 AS (
-    SELECT geom, 'ocean' AS class FROM ne_50m_ocean
-    UNION ALL
-    SELECT geom, 'lake' AS class FROM ne_110m_lakes
-    UNION ALL
-    SELECT geom, 'river' AS class FROM ne_110m_rivers_lake_centerlines
-    WHERE featurecla = 'River'
-);
-
 CREATE OR REPLACE VIEW water_z4 AS (
     SELECT geom, 'ocean' AS class FROM ne_50m_ocean
     UNION ALL
     SELECT geom, 'lake' AS class FROM ne_50m_lakes
-    UNION ALL
-    SELECT geom, 'river' AS class FROM ne_50m_rivers_lake_centerlines
-    WHERE featurecla = 'River'
 );
 
 CREATE OR REPLACE VIEW water_z5 AS (
     SELECT geom, 'ocean' AS class FROM ne_10m_ocean
     UNION ALL
     SELECT geom, 'lake' AS class FROM ne_10m_lakes
-    UNION ALL
-    SELECT geom, 'river' AS class FROM ne_50m_rivers_lake_centerlines
-    WHERE featurecla = 'River'
 );
 
 CREATE OR REPLACE VIEW water_z6 AS (
     SELECT geom, 'ocean' AS class FROM ne_10m_ocean
     UNION ALL
     SELECT geom, 'lake' AS class FROM ne_10m_lakes
-    UNION ALL
-    SELECT geom, 'river' AS class FROM ne_10m_rivers_lake_centerlines
-    WHERE featurecla = 'River'
 );
 
 CREATE TABLE IF NOT EXISTS water_z7 AS (
     SELECT geom, 'ocean' AS class FROM ne_10m_ocean
     UNION ALL
     SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon_gen3
-    UNION ALL
-    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);
 
@@ -66,57 +45,38 @@ CREATE TABLE IF NOT EXISTS water_z8 AS (
     SELECT geom, 'ocean' AS class FROM ne_10m_ocean
     UNION ALL
     SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon_gen2
-    UNION ALL
-    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 geometry AS geom, 'lake' AS class FROM osm_water_polygon_gen1
-    UNION ALL
-    SELECT ST_Simplify(geometry, 100) AS geom, waterway AS class FROM osm_water_linestring
-    WHERE waterway IN ('river') AND ST_Length(geometry) > 5000
+    SELECT geometry AS geom, 'lake'::text AS class FROM osm_water_polygon_gen1
 );
 CREATE INDEX IF NOT EXISTS water_z9_geom_idx ON water_z9 USING gist(geom);
 
 CREATE OR REPLACE VIEW water_z11 AS (
     SELECT geometry AS geom, 'lake' AS class FROM osm_water_polygon WHERE area > 40000
-    UNION ALL
-    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 geometry AS geom, 'lake' AS class FROM osm_water_polygon WHERE area > 10000
-    UNION ALL
-    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 geometry AS geom, 'lake' AS class FROM osm_water_polygon WHERE area > 5000
-    UNION ALL
-    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 geometry AS geom, 'lake' AS class FROM osm_water_polygon
-    UNION ALL
-    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, class text) AS $$
-    SELECT geom, class FROM (
+    SELECT geom, class::text FROM (
         SELECT * FROM water_z0 WHERE zoom_level = 0
         UNION ALL
         SELECT * FROM water_z1 WHERE zoom_level = 1
         UNION ALL
-        SELECT * FROM water_z2 WHERE zoom_level = 2
-        UNION ALL
-        SELECT * FROM water_z3 WHERE zoom_level = 3
+        SELECT * FROM water_z2 WHERE zoom_level BETWEEN 2 AND 3
         UNION ALL
         SELECT * FROM water_z4 WHERE zoom_level = 4
         UNION ALL
diff --git a/layers/waterway/mapping.yaml b/layers/waterway/mapping.yaml
new file mode 100644
index 00000000..dadf9e3b
--- /dev/null
+++ b/layers/waterway/mapping.yaml
@@ -0,0 +1,24 @@
+tables:
+  waterway_linestring:
+    type: linestring
+    fields:
+    - name: osm_id
+      type: id
+    - name: geometry
+      type: geometry
+    - name: waterway
+      key: waterway
+      type: string
+    - key: name
+      name: name
+      type: string
+    - name: name_en
+      key: name:en
+      type: string
+    mapping:
+      waterway:
+      - stream
+      - river
+      - canal
+      - drain
+      - ditch
diff --git a/layers/waterway/waterway.sql b/layers/waterway/waterway.sql
new file mode 100644
index 00000000..79e75d0c
--- /dev/null
+++ b/layers/waterway/waterway.sql
@@ -0,0 +1,69 @@
+CREATE OR REPLACE VIEW waterway_z3 AS (
+    SELECT geom, 'river' AS class FROM ne_110m_rivers_lake_centerlines
+    WHERE featurecla = 'River'
+);
+
+CREATE OR REPLACE VIEW waterway_z4 AS (
+    SELECT geom, 'river' AS class FROM ne_50m_rivers_lake_centerlines
+    WHERE featurecla = 'River'
+);
+
+CREATE OR REPLACE VIEW waterway_z6 AS (
+    SELECT geom, 'river' AS class FROM ne_10m_rivers_lake_centerlines
+    WHERE featurecla = 'River'
+);
+
+CREATE TABLE IF NOT EXISTS waterway_z8 AS (
+    SELECT ST_Simplify(geometry, 200) AS geom, waterway AS class FROM osm_waterway_linestring
+    WHERE waterway IN ('river') AND ST_Length(geometry) > 10000
+);
+CREATE INDEX IF NOT EXISTS waterway_z8_geom_idx ON waterway_z8 USING gist(geom);
+
+CREATE TABLE IF NOT EXISTS waterway_z9 AS (
+    SELECT ST_Simplify(geometry, 100) AS geom, waterway AS class FROM osm_waterway_linestring
+    WHERE waterway IN ('river') AND ST_Length(geometry) > 5000
+);
+CREATE INDEX IF NOT EXISTS waterway_z9_geom_idx ON waterway_z9 USING gist(geom);
+
+CREATE OR REPLACE VIEW waterway_z11 AS (
+    SELECT geometry AS geom, waterway AS class FROM osm_waterway_linestring
+    WHERE waterway IN ('river') AND ST_Length(geometry) > 5000
+);
+
+CREATE OR REPLACE VIEW waterway_z12 AS (
+    SELECT geometry AS geom, waterway AS class FROM osm_waterway_linestring
+    WHERE waterway IN ('river', 'canal') OR (waterway = 'stream' AND ST_Length(geometry) > 1000)
+);
+
+CREATE OR REPLACE VIEW waterway_z13 AS (
+    SELECT geometry AS geom, waterway AS class FROM osm_waterway_linestring
+    WHERE waterway IN ('river', 'canal', 'stream', 'drain', 'ditch') AND ST_Length(geometry) > 300
+);
+
+CREATE OR REPLACE VIEW waterway_z14 AS (
+    SELECT geometry AS geom, waterway AS class FROM osm_waterway_linestring
+);
+
+CREATE OR REPLACE FUNCTION layer_waterway(bbox geometry, zoom_level int)
+RETURNS TABLE(geom geometry, waterway text) AS $$
+    SELECT geom, class FROM (
+        SELECT * FROM waterway_z3 WHERE zoom_level = 3
+        UNION ALL
+        SELECT * FROM waterway_z4 WHERE zoom_level BETWEEN 4 AND 5
+        UNION ALL
+        SELECT * FROM waterway_z6 WHERE zoom_level BETWEEN 6 AND 7
+        UNION ALL
+        SELECT * FROM waterway_z8 WHERE zoom_level = 8
+        UNION ALL
+        SELECT * FROM waterway_z9 WHERE zoom_level BETWEEN 9 AND 10
+        UNION ALL
+        SELECT * FROM waterway_z11 WHERE zoom_level = 11
+        UNION ALL
+        SELECT * FROM waterway_z12 WHERE zoom_level = 12
+        UNION ALL
+        SELECT * FROM waterway_z13 WHERE zoom_level = 13
+        UNION ALL
+        SELECT * FROM waterway_z14 WHERE zoom_level >= 14
+    ) AS zoom_levels
+    WHERE geom && bbox;
+$$ LANGUAGE SQL IMMUTABLE;
diff --git a/layers/waterway/waterway.yaml b/layers/waterway/waterway.yaml
new file mode 100644
index 00000000..87b4da22
--- /dev/null
+++ b/layers/waterway/waterway.yaml
@@ -0,0 +1,12 @@
+layer:
+  id: "waterway"
+  description: |
+      OpenStreetMap waterways.
+  buffer_size: 4
+  datasource:
+    query: (SELECT * FROM layer_waterway(!bbox!, z(!scale_denominator!))) AS t
+schema:
+  - ./waterway.sql
+datasources:
+  - type: imposm3
+    mapping_file: ./mapping.yaml
diff --git a/openmaptiles.yaml b/openmaptiles.yaml
index 206181ae..46a06dad 100644
--- a/openmaptiles.yaml
+++ b/openmaptiles.yaml
@@ -7,9 +7,10 @@ tileset:
     - layers/state/state.yaml
     - layers/country/country.yaml
     - layers/place/place.yaml
-    #- layers/rail/rail.yaml
+      #- layers/rail/rail.yaml
     - layers/urban/urban.yaml
     - layers/water/water.yaml
+    - layers/waterway/waterway.yaml
     - layers/landcover/landcover.yaml
   name: OpenMapTiles v1.0
   description: "A tileset showcasing all layers in OpenMapTiles. http://openmaptiles.org"