Uganda has fertile soils and abundant natural resources. Control of productive land is inequitably distributed across the regions, between income groups and by gender. The Constitution (1995) vests land in the citizens and recognizes four historic forms of land tenure'customary, leasehold, freehold, and mailo (a customary form of freehold land). Most rural people have rights to their land through customary tenure arrangements (representing 75%-80% of landholdings). Only 15%-20% of the land is formally registered. Uganda has significant water resources, but these resources are not evenly distributed across the landscape. The Director of Water Development grants surface water and groundwater permits; discharge is prohibited without permit. Forests cover 4.9 million hectares (24% of land). About 30% of the forest'1.9 million hectares'is in the protected estate; 70% is on private land. All commercial operations in Central Forest Reserves must be licensed. Uganda's leading mineral export is gold, although activities extend to other minerals. Commercially-viable quantities of oil have recently been discovered in western Uganda. In 2005, a Constitutional amendment was passed that vests the ownership of minerals and petroleum in the government. The exploration and exploitation of minerals requires a license; a separate permit is required to utilize natural water resources for mining. Drilling for oil or natural gas requires a Petroleum Production License.