The sludge cake of P. australis STWs retained the lowest amount of water (19 ± 5 L m−2),while the other plant species and the unplanted control retained about 13 L more water per surface (34 ± 2 L m−2, 33 ± 6 L m−2 and 31 ± 15 L m−2 for T. angustifolia, unplanted and S. fluviatilis, respectively)