(or Megrenka), a river in Arkhangel’sk Oblast, RSFSR; a right tributary of the Emtsa River (Severnaia Dvina basin). Length, 231 km. Basin area, 5,080 sq km. In the upper course the Mekhren’ga flows through a number of lakes. It is a winding river, fed primarily by snow. The mean flow rate 32 km from the mouth is 33 cu m per sec. The river freezes over in November, with the ice breaking up in April or early May. The water is mineralized. There is karst in the basin.