Next to the Estacada weir, a construction built in the stream bed to retain water for irrigating the surrounding fields, you can see a riverside landscape with an ecosystem consisting of the stream bed, through which the water drains, and the riparian gallery, the corridor of riverside vegetation which surrounds the stream bed to a variable extent. In the absence of human intervention and depending on the topography and substrate, the stream tends to develop a meandering natural course as a result of erosion and deposition. The banks tend to be irregular and the slope not very steep.
Human intervention in the water courses has led to a regularisation and artificialisation of its bed and banks, a process that can be observed at this site.
The natural riparian galleries of the Ribeira de Quarteira are shrubby galleries dominated by oleander, tamarisk and bushweeds. On the deeper soils, the ash tree occurs.
The structure of the natural riparian vegetation is invaded by a species that is very common in Portugal - the reed, an exotic species native to the eastern Mediterranean and tropical regions, with a behaviour that occupies the habitat of native species, consuming their resources (water, soil and light), and leading to the reduction of native populations or even their extinction. In some stretches of the Ribeira de Quarteira this species is the only occupant of the riparian gallery.