The biggest long-term problem inside Borneo’s peat-swamp forests is drainage, the artificial construction of canals and channels inside the forest that causes the peat to dry out and sends the fire-risk skyrocketing.
Even though most peat-swamp forests are now protected in Kalimantan, under the Indonesian government’s moratorium on conversion of peatlands, they remain threatened by the long-term consequences of rampant illegal logging and failed development programmes in this habitat during the late 1990’s and early 2000’s.
A network of large canals were dug to drain the peatland for planned agricultural projects that have long-since failed. Inside the forest, illegal loggers cut narrow channels into the peat to float out felled timber, hundreds of them inside Sebangau National Park alone, several stretching over 10km into the forest. These channels remain long after the immediate problem has been solved, and drain the once water-logged peat every dry-season.
In their natural state these forests are permanently flooded and new peat accumulates, but when the peat is drained it dries out, oxidises and degrades, putting the whole ecosystem at risk. The crumbling peat surface undermines shallow-rooted trees, and little water is retained in the peat by the end of the dry season. Dried peat is highly flammable and fires frequently break out in the forest margins and the surrounding sedge swamp, sometimes burning large areas. Huge areas of drained peatland have been laid waste by fires over the past 15 years, representing a true ecological disaster.
We work to solve this problem by blocking illegal-logging channels together with CIMTROP and the Community Patrol Team. This slows the rate of dry-season drawdown, thus retaining water in the system, raising the water-table and keeping the peat wetter for longer; it keeps forest litterfall in the ecosystem, filling the canals in naturally; and the dams discourage people from entering the forest to remove more timber. We are building dams on each of 24 mapped canals in the northern Sebangau National Park, built primarily using sustainable natural materials by teams from the local village. We aim to build a dam every 50m for the first kilometre and every 100-200m inland from the river.
Larger dams are built at the mouth of each canal and smaller, 1m-thick dams are placed every 100m for the first kilometre and every 200m further inland. These dams are overplanted with vegetation to create a permanent, living dam. The dammed canals are monitored regularly by measuring water flow rate and water tables, and checking and repairing dams as necessary. We can show the effectiveness of the dams in retaining water in the ecosystem and slowing discharge-rates.
To date we have built over 600 dams and we continue to work on this project throughout the year.