Assegaai River, originates north of Wakkerstroom, Mpumalanga, South Africa, and runs into the Heyshope Dam, southeast of Piet Retief. When it enters Swaziland it is known as the Mhkondvo River and it cuts through the mountains forming the . In Swaziland it flows generally northeastward and eventually into the Usuta River. Tributaries of the Assegaai include the , the , the Boesmanspruit, and the .