int id;
    net.minecraft.server.Chunk mcChunk;
    int j1;
    ChunkSection[] sections = null;
    ChunkSection chunksection;
//  Location loc;
    List<ChunkCoordIntPair> chunkCoordIntPairQueue;
    ChunkCoordIntPair ccip;
    int y1 = at.waterHeight >> 4;
    int y2 = at.waterHeight & 15;
    boolean tr;
    boolean changed;
    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[y1];
      if(chunksection == null)
        chunksection = sections[y1] = new ChunkSection(at.waterHeight >> 4 << 4);

      changed = false;
      long ts = System.currentTimeMillis();
      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, y2, z);
          tr = false;
          for(int trid: at.toReplace)
          {
            if(id == trid)
            {
              tr = true;
              break;
            }
          }
          if(up)
          {
            if(id == at.air || tr)
            {
              chunksection.a(x, y2, z, at.water2);
              changed = true;
            }
          }
          else if(id == at.water1 || id == at.water2 || tr)
          {
            chunksection.a(x, y2, z, at.air);
            changed = true;
          }
          else if(id == at.grass)
          {
            chunksection.a(x, y2, z, at.dirt);
            changed = true;
          }
        }
      }

      if(changed)
      {
          long ts2 = System.currentTimeMillis();
        mcChunk.initLighting();
        long ts3 = System.currentTimeMillis();
        ccip = new ChunkCoordIntPair(mcChunk.x, mcChunk.z);
        for(Player p: world.getPlayers())
        {
/*        loc = p.getLocation();
          int px = loc.getBlockX() - (mcChunk.x * 16);
          int pz = loc.getBlockZ() - (mcChunk.z * 16);
          if((px * px) + (pz * pz) < threshold)
          {*/
            chunkCoordIntPairQueue = (List<ChunkCoordIntPair>)((CraftPlayer)p).getHandle().chunkCoordIntPairQueue;
            if(!chunkCoordIntPairQueue.contains(ccip))
              chunkCoordIntPairQueue.add(ccip);
//        }
        }
        System.out.print("Replacing blocks: "+(ts2 - ts)+"ms - relighting chunk: "+(ts3-ts2)+"ms - Adding package to queues: "+(System.currentTimeMillis()-ts3)+"ms");
//      loc = null;
      }
    }