Sioule

Sioule is a river in central France that serves as a principal left‑hand tributary of the Allier. The river originates in the Massif Central, near the village of Villaret, at an altitude of about 1,000 meters. From its source it flows southwest through a series of gorges and valleys, eventually joining the Allier near the town of Marvejols. The overall length of the Sioule is approximately 70 kilometers. Its drainage basin covers an area of roughly 1,200 square kilometers, and the river’s average discharge at its mouth is about 15 cubic meters per second.

Along its course the Sioule receives several smaller tributaries, most notably the Lagnièvre and the Cuisien, which contribute significantly to its seasonal flow variations. The river’s steep gradients in the upper reaches create a number of fast‑flowing segments that make it attractive for activities such as white‑water kayaking and fishing for brown trout. In the middle and lower reaches the water is more tranquil, and the surrounding valleys are populated by several communes including Saint-Amand-Montrond, Puy-en-Velay, and Montigny.

Human impact on the Sioule includes a handful of small hydroelectric plants which provide renewable energy for the region. Ecologically the river supports a range of habitats, from alpine tundra in its headwaters to wetland marshes near its confluence with the Allier. Conservation efforts focus on maintaining water quality and preserving the natural landscape, which in turn supports both biodiversity and local tourism.