The Sinni (Siris, Σίρις in Greek) is the fourth-longest river in Basilicata in terms of length and catchment area, and the second-richest in water, after the Agri; it winds its way extensively along the Pollino National Park.
This is an extremely torrential river which is affected by the incessant rain, leading to floods that are at times a cause for concern.
Conversely, during periods of drought, the river experiences low water levels, although its flow remains unaffected thanks to the numerous springs in its upper catchment area.
The Sinni rises at an altitude of 1,380 metres from the summit of the Serra della Giumenta, to the west of the Sirino.
It is precisely from Running from west to east, it cuts through the southern part of the region, receiving several tributaries:
- Cogliandrino
- Peschiera-Frido
- Rubbio
- Serrapotamo
It is precisely the Serrapotamo has a course that is closed off by a earth-filled dam (the largest in Europe), built between 1970 and 1982.
The dam led to the creation of the the artificial lake at Monte Cotugno, one of the largest in the country, with a capacity of 530 million cubic metres, serving to a large extent, the water reserves of Lucania and Puglia.
Once it reaches the valley, the Sinni will then flow into the municipality of Valsinni with the Sarmento, its main tributary. At this point, the riverbed widens considerably, reaching a width of as much as one kilometre.
Near Policoro It flows into the Metaponto Plain and from there empties into the Ionian Sea.
Among the fish species which inhabit the Sinni,
- chub
- common barbel
- brown trout
- little dog
- royal perch
- loach
- the Apennine minnow, which requires special protection
- trout perch
- carp
- tench
- crucian carp
- eels
- catfish
