“ The river is usually shallow and is fordable at many places, known as drifts. But after the heavy summer rains the stream attains a depth of 30 or more feet. At such times the banks, which are lined with willows and in places very steep, are inundated. As a rule little water is added to the Vaal by its tributaries. Of these, the Wilge (190 m.) , which also rises on the inner slopes of the Drakensberg, flows first S.W., then N .W. across the eastern part of Orange Free State and joins the Vaal 60 m. below the Klip confluence. ”