Malolotja Nature Reserve - Hydrology
The reserve has innumerable perennial streams and rivers. In addition there are several upland vleis that retain water throughout the year, the most important of which is the Malolotja vlei. The reserve includes virtually the entire catchment area for the Malolotja, Mgwayiza and Mhlangamphepha rivers, and the Nkomati river cuts through the reserve, running from west to east. Prior to the establishment of the reserve a number of dams, weirs and barrages were built on the rivers. No boreholes have been sunk anywhere in the reserve and no artificial watering points for animals have been made, although various artificial impoundments within or on the boundary of the reserve are undoubtedly used by animals. Water quality is generally good and requires little or no treatment, apart from the Nkomati and Mkomazane Rivers. There is also some pollution of the Malolotja river from the portion of its catchment which lies outside the reserve boundary.