[out:xml][timeout:99999][maxsize:2073741824];
(
  way["natural"="water"](50.7,-11.4,81.5,41.7)(if:count_members()>4000);
  relation["natural"="water"](50.7,-11.4,81.5,41.7);
  way["waterway"="riverbank"](50.7,-11.4,81.5,41.7)(if:count_members()>4000);
  relation["waterway"="riverbank"](50.7,-11.4,81.5,41.7);
);
(._;>;);
out body;