Wikipedia
The Titarisios (, formerly Ξεριάς - Xerias) is a river in Thessaly, Greece. It is a major tributary of the Pineios. The river begins at the western slopes of Mount Olympus and flows southwest, then south. It leaves the mountains near the village Sykia, and turns east near the village Vlachogianni. It passes along the town Tyrnavos and flows into the Pineios near the village Rodia. The confluence is at 65 m above sea level. Its total length is 70 km, and for most of its length it contains water throughout the year.
The vegetation along the river is characterised by reeds, mainly the Phragmites australis, and by wetland forest with trees like plane trees, willows and poplars. According to the classification system of wetland types of the Ramsar Convention adopted in 1999, the Titarisios river falls into the category of inland wetlands. The river is currently primarily used for irrigation, although this has been declining recently. Major construction projects have caused drastic changes to the wetlands. The wetlands of the Titarisios are threatened by uncontrolled waste disposal, for instance near the villages Rodia, Vryotopos and Deleria.
Around 3 km from Argyroupoli is Lake Mati Tyrnavou. Mati is today the only natural lake in Thessaly and although it has only a small area (25 ha) it is the core of an ecosystem with rich flora and fauna.