Blocks manipulation

Hello,

What I wanted: Replace all the water and stationary water blocks with a block of grass above and below the dirt blocks in a predefined radius.

What I got: I was able to replace all the water and stationary water with dirt and grass blocks but the grass blocks are not aligned at all and have a disgusting appearance (as in the picture).



What I would like to get:



My code:

PHP:

    public void settingBiome(World world, int radius) {
        for (double x = world.getSpawnLocation().getX() - radius; x <= world.getSpawnLocation().getX() + radius; x++) {
            for (double y = world.getSpawnLocation().getY() - radius; y <= world.getSpawnLocation().getY() + radius; y++) {
                for (double z = world.getSpawnLocation().getZ() - radius; z <= world.getSpawnLocation().getZ() + radius; z++) {
                    Location loc = new Location(world, x, y - 1, z);
                    if(loc.getBlock().getType() == Material.WATER || loc.getBlock().getType() == Material.STATIONARY_WATER) {
                        loc.getBlock().getRelative(BlockFace.UP).setType(Material.GRASS);
                        loc.getBlock().setType(Material.DIRT);
                    }
                }
            }
        }
    }

Thanks to all people who will help me to solve this problem, the others, go your way.