Gaste

The Gaste is one of Messenia's most important rivers; its drainage basin covers a large part of Northern Messenia, roughly corresponding to two-thirds of the Central Messenian Plain.

The Gaste emerges in the south-eastern Aphrasians in Elland (county of Litherland) and flows toward the north-east, collecting several important left-bank tributaries also descending from the Aphrasians, including the Bain just south of Etherley. The Gaste then meets the Marduine at Gannsford just before exiting Elland to enter Emilia at its confluence with the Brede, which forms the border between Elland and Emilia for much of its length; it is joined by the Semme to the east in central Emilia, with the town of Troarn located on the south bank where the two rivers converge. The Gaste drains into Lake Carles at Pont d’Chélîn, which marks the end of the Upper Gaste Basin and its transition to the Middle Gaste and, further downstream, the Lower Gaste. The river's last major tributary is the Réale, which merges from the right-bank shortly after the Lake Carles outflow where the Savamese city of Maconfle is located. The Bend of Adaque is a major geographic feature in Middle Gaste from where the river flows almost directly north and waters the major Savamese cities of Taurive, Sévinne, Quesailles, Saint-Julien-sur-Gaste, and Jagues-Salins. The city of Sévinne marks the end of Middle Gaste and beginning of Lower Gaste.

Two major canals connect the Gaste with the Génestre: the 99-kilometre Southern Génestre-Gaste Canal which links Taurive and Poignes (on the Twin Lakes), and the 217-kilometre Northern Génestre-Gaste Canal which links Quesailles to the Génestre ninety kilometres west of Porians.