Derkul

The Derkul is a left tributary of the Donets located in the Luhansk Oblast of northeast Ukraine, on the border to the Rostov Oblast of Russia. It is 163 km long, and has a catchment area of 5180 km2.

The Derkul rises north of Markivka in the Ukrainian Luhansk Oblast on the western foothills of the Central Russian Upland. It flows mainly in a southerly direction through a hilly plain in the northeast of the oblast and after 163 km flows on the left into the Siverskyi Donets. In parts of the lower course, it forms a border of the Rostov Oblast of Russia. The Derkul flows through the urban-type settlement of Bilovodsk at the lower reaches. The most important tributary of the Derkul is the Polnaya from the left.