Water scarcity and the high costs of new water supply technologies are the two major factors responsible for the increasing recognition of the importance to conserve water resources by wastewater treatment, reuse or reclamation. Sustainability of sanitation systems should be related to low cost, low energy consumption and operation and maintenance requirements, especially for small communities in developing countries. Hence, natural systems for wastewater treatment seem to be a suitable solution. In this study, a review of two natural systems, constructed wetlands and stabilization ponds, was carried out. Thereby, strengths and weakness of both systems have been analysed. Furthermore, this dissertation evaluates the robustness of a pilot-scale hybrid constructed wetland system to cope with a heavy rain episode, a characteristic phenomenon in tropical climate regions.