The Opir is 58 kilometres (36 mi) long, with a basin size of 843 km2 (325 sq mi).[1] Its average stream gradient is 10.4 m/km (55 ft/mi).[1] The river flows in a V-shaped valley, with a width varying between 150 m (490 ft) and 300 m (980 ft) in the lower reaches.[1] The floodplain is bilateral, sometimes unilateral, with a width ranging from 30 metres (98 ft) to 425 metres (1,394 ft). The shores are steep and occasionally swampy. The stream bed is rocky, with a width of 10 metres (33 ft) to 80 metres (260 ft), and a depth of 0.2 metres (7.9 in) to 1.2 metres (3 ft 11 in). The bottom is usually lined with pebbles of Carpathian sandstones. The river supplies water for settlements and for the irrigation of agricultural lands.
Recently, the river has become popular among tourists who go rafting.[4]
Tributaries
Eight small rivers and 31 streams with a total length of 94.3 kilometres (58.6 mi) and an area of 21.9 hectares (54 acres) flow into the river.
^ abcdeAnna Hryhorivna Lutsyk, Pavlo Volodymyrovych Bosak (2019). "Антропогенне забруднення річок смт. Славське" [Anthropogenic pollution of rivers in the town of Slavske] (PDF). Проблеми та перспективи розвитку системи безпеки життєдіяльності (in Ukrainian): 163–165.
^ abPrykhodko, M. M.; Romaniuk, V. V.; Kukhtar, D. V.; Bodnaruk, I. L.; Adamovych, M. V. (2020). "Use of geoinformation technology to study the structure and morphometric parameters of river basins". Geoinformatics: Theoretical and Applied Aspects 2020: 1–5. doi:10.3997/2214-4609.2020geo014.