UNEP, in its report “Orangutans and the Economics of Sustainable Forest Management in Sumatra” analysed the value of different land uses in Batang Toru as a special case study.



They found that carbon trading through a REDD programme could match or even exceed the earnings from other land uses such as oil palm plantations and logging. This valuation didn’t even take into account the value of environmental services provided by the forests or the economic losses that would be incurred if the forests are damaged.

These environmental services include:

  • Stable fresh water supplies for local people, agriculture and industry;
  • Prevention of landslides, flooding, erosion and sedimentation of rivers;
  • Climate regulation including air temperature control;
  • Formation and fertility of soils;
  • Pollination of commercial species such as durian; and
  • Tourism potential.

Water from the Batang Toru forests is vital for the people of the 3 Tapanuli districts, especially for their plantations and wet rice cultivation, and their daily household needs. Extensive paddy fields in the Sarulla valley and other areas receive their irrigations from the Batang Toru forests. Mixed rubber agro-forestry gardens that are the mainstay of local people’s economy all depend on rainfall from these forests. Similarly, the Sipansihaporas hydro-electricity plant and the Aek Raisan micro-hydro plants are completely dependent on water from these forests.


Stable forested watershed ecosystems are vital for the 300 MW Geothermal Electricity Plants under construction in the Sarulla valley between the east and west forest blocks.

The gold mine currently operating in the Batang Toru sub-district in South Tapanuli also needs water from the west block of the Batang Toru Ecosystem, and the downstream coastal plain is covered by oil palm plantations also dependent on the hydrology of the river.