private void makeWaterRandom() {

	for (int i = 0; i < mapWidth; i++) {

	    for (int k = 0; k < mapHeight; k++) {

		if (map[i][k] == Tile.water) {

		    boolean generateTile = new Random().nextBoolean();
		    if (generateTile)
			map[i][k] = Tile.water2;

		    if (map[i - 1][k] == Tile.grass || map[i - 1][k] == Tile.grass2)
			map[i][k] = Tile.water; // ersetzen mit Wasserübergang
		    if (map[i + 1][k] == Tile.grass || map[i + 1][k] == Tile.grass2)
			map[i][k] = Tile.water;
		    if (map[i][k - 1] == Tile.grass || map[i][k - 1] == Tile.grass2)
			map[i][k] = Tile.water;
		    if (map[i][k + 1] == Tile.grass || map[i][k + 1] == Tile.grass2)
			map[i][k] = Tile.water;
		}

	    }

	}

    }