The Mule Hole watershed is located in the middle of the forest. It covers an area of about 4.5 square km and belongs to the Soreda Halla basin (43 square km). The Soreda Halla River is a tributary of the Nugu Hole River, which itself flows northwards before reaching the Kabini River. It is mostly ondulating with gentle slopes and elevation varies from 820 to 910 m asl, with an average value of 860 m (Figure 1). The surface outlet is located on the south-western part of the watershed.
The Maddur watershed (Figure 2) stretches east of Mule Hole on about 7 square km, at the edge of the forest. It includes a cultivated zone (about 1/3d of its area). The watershed is part of the western boundary of the Gundal basin. The Gundal River flows northwards until it reaches the Kabini River in Nanjangud. The Gundal basin is completely included in the semi-arid area.