CREATE OR REPLACE VIEW water_z0 AS (
    SELECT geom FROM ne_110m_ocean
    UNION ALL
    SELECT geom FROM ne_110m_lakes
);

CREATE OR REPLACE VIEW water_z1 AS (
    SELECT geom FROM ne_110m_ocean
    UNION ALL
    SELECT geom FROM ne_110m_lakes
);

CREATE OR REPLACE VIEW water_z2 AS (
    SELECT geom FROM ne_50m_ocean
    UNION ALL
    SELECT geom FROM ne_110m_lakes
);

CREATE OR REPLACE VIEW water_z3 AS (
    SELECT geom FROM ne_50m_ocean
    UNION ALL
    SELECT geom FROM ne_110m_lakes
    UNION ALL
    SELECT geom FROM ne_110m_rivers_lake_centerlines
    WHERE featurecla = 'River'
);

CREATE OR REPLACE VIEW water_z4 AS (
    SELECT geom FROM ne_50m_ocean
    UNION ALL
    SELECT geom FROM ne_50m_lakes
    UNION ALL
    SELECT geom FROM ne_50m_rivers_lake_centerlines
    WHERE featurecla = 'River'
);

CREATE OR REPLACE VIEW water_z5 AS (
    SELECT geom FROM ne_10m_ocean
    UNION ALL
    SELECT geom FROM ne_10m_lakes
    UNION ALL
    SELECT geom FROM ne_50m_rivers_lake_centerlines
    WHERE featurecla = 'River'
);

CREATE OR REPLACE VIEW water_z6 AS (
    SELECT geom FROM ne_10m_ocean
    UNION ALL
    SELECT geom FROM ne_10m_lakes
    UNION ALL
    SELECT geom FROM ne_10m_rivers_lake_centerlines
    WHERE featurecla = 'River'
);

CREATE OR REPLACE VIEW water_z8 AS (
    SELECT way AS geom FROM water_areas
    WHERE way_area > 100000
);

CREATE OR REPLACE VIEW water_z11 AS (
    SELECT way AS geom FROM water_areas
    WHERE way_area > 50000
);

CREATE OR REPLACE VIEW water_z12 AS (
    SELECT way AS geom FROM water_areas
    WHERE way_area > 40000
);

CREATE OR REPLACE VIEW water_z13 AS (
    SELECT way AS geom FROM water_areas
    WHERE way_area > 2000
);

CREATE OR REPLACE VIEW water_z14 AS (
    SELECT way AS geom FROM water_areas
);