I explored many long kilometers of Levadas during my week trip to Madeaira in January 2012. We crossed the island by walk, and naturally, these canals, designed for efficient water management of the island, were more than often only possibilities how to commute in the rocky landscape of Madeira. I have strong memories especially to 1 or even 2 km long tunnels, where your own light is a necessity, and the stream of water in Levadas is so rapid but very silent there. I think that this water management system would deserve WHS status much more that the canals in Augsburg.
The net of Levedas is quite dense and but they are diverse (I liked Levada da Janela, Levada das 25 Fontes, Levada do Risco, Levada do Paul, Levadas to the Souths from Sao Vincento, and Levadas around Ribeiro Frio, etc.). Most of them are still in use, but we saw also some parts without water. However, even dry Levadas are very useful for walking in otherwise impenetrable landscape. In the relatively small parts of central plateau, we also walked along untypical types of Levadas that are not such dramatic but still beautiful, as shown in PHOTO (parts of Levada do Paul).