An extensive "regreening" and reforestation of barren land, initiated under the 1975–79 national economic development plan, was greatly expanded and integrated with flood control and irrigation programs under the national plans for 1979–84 and 1984–89. From the mid-1980s to the mid-1990s, Indonesia's forests and woodland areas increased by 1.4%. Indonesia also has the world's most extensive mangrove area, which covered over 4 million ha (9.9 million acres) in 1994. Flood-control programs involve river dredging, dike strengthening, construction of new dams, and sandbagging of river banks at critical points. The burning of oil and coal along with the abuse of fertilizers and pesticides results in significant damage to the environment. The nation used 3.1 million tons of fertilizer per year at last estimate. The nation's cities produce about 12.9 million tons of solid waste per year. Indonesia has 2,838 cu km of renewable water resources with 93% used in farming activity and 1% used for industrial purposes. About 90% of all city dwellers and 69% of rural dwellers have access to pure drinking water. Legislation introduced in 1982 endorsed the establishment of penalties for environmental pollution.
Protection of indigenous wildlife is entrusted to the Directorate of Nature Conservation and Wildlife Management. In 1984/85, the government set up three new national parks, part of 19 included in the 1984–89 plan, and four new natural reserves. As of 1986 there were 146 parks and nature reserves, with more in the planning stage; the government's goal was to allocate 10% of the nation's land area to reserves. By 2001 this goal had been met—protected lands totaled 10.1% of Indonesia's total land area. Indonesia's coastal waters are among the world's richest in biodiversity of marine life. As of 2001, 128 of Indonesia's mammal species were endangered and 104 bird species were threatened with extinction. Endangered species in Indonesia include the pig-tailed langur, Javan gibbon, orangutan, tiger, Asian elephant, Malayan tapir, Javan rhinoceros, Sumatran rhinoceros, Sumatran serow, Rothschild's starling, lowland anoa, mountain anoa, Siamese crocodile, false gavial, river terrapin, and four species of turtle (green sea, hawksbill, olive ridley, and leatherback). Buhler's rat and the Javanese lapwing have become extinct.