int id;
    net.minecraft.server.Chunk mcChunk;
    int j1;
    ChunkSection[] sections = null;
    ChunkSection chunksection;
    List<Player> playerList = world.getPlayers();
    for(Chunk c: world.getLoadedChunks())
    {
      mcChunk = ((CraftChunk)c).getHandle();
      try
      {
        sections = (ChunkSection[])f.get(mcChunk);
      }
      catch(Exception e)
      {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
      chunksection = sections[at.waterHeight >> 4];
      if(chunksection == null)
        chunksection = sections[at.waterHeight >> 4] = new ChunkSection(at.waterHeight >> 4 << 4);

      for(int x = 0; x < 16; x++)
      {
        for(int z = 0; z < 16; z++)
        {
          j1 = z << 4 | x;

          if(at.waterHeight > mcChunk.b[j1] - 1)
            mcChunk.b[j1] = -999;
          id = chunksection.a(x, at.waterHeight & 15, z);
          if(up)
          {
            if(id == air || id == leaves)
            {
              chunksection.a(x, at.waterHeight & 15, z, water);
              if(id == leaves)
                Block.byId[leaves].remove(mcChunk.world, mcChunk.x * 16 + x, at.waterHeight, mcChunk.z * 16 + z);
            }
            else if(id == grass)
            {
              chunksection.a(x, at.waterHeight & 15, z, dirt);
              Block.byId[id].remove(mcChunk.world, mcChunk.x * 16 + x, at.waterHeight, mcChunk.z * 16 + z);
            }
          }
          else if(id == water)
          {
            chunksection.a(x, at.waterHeight & 15, z, air);
            Block.byId[id].remove(mcChunk.world, mcChunk.x * 16 + x, at.waterHeight, mcChunk.z * 16 + z);
          }
          mcChunk.l = true;
        }
      }
      Packet51MapChunk packet = new Packet51MapChunk(mcChunk, true, 0);
      for(Player p: playerList)
        ((CraftPlayer)p).getHandle().netServerHandler.sendPacket(packet);
    }
  }