The longest of the four rivers which drain the central part of the Atlantic area is the Ugab, with a length of 486 km. It has its origin on the flats and mountain slops near Otavi. The Otavi highlands is one of the highest rainfall areas in South West Africa, with an average rainfall figure of about 500 mm. Also the number of days of rainfall for the upper Ugab area is the highest, viz. 70 days p.a. on an average. Keywords: Ugab River, Otavi highlands, High rainfall.