Lake Toba
Experience and Lessons Learned Brief
Haryatiningsih Moedjodo*, LakeNet Country Director-Indonesia, ning@worldlakes.org
Payaman Simanjuntak, Lake Toba Heritage Foundation, Jakarta, Indonesia
Peter Hehanussa, Indonesian Institute of Sciences, Cibinong, Indonesia
Lufi andi, West Java Environmental Impact Management Agency, Bandung, Indonesia
* Corresponding author
1. Introduction
level. Biophysically, the cool, refreshing environment, clean air,
and fertile soil of the region make it an ideal place for human
Lake Toba is Indonesia's largest lake, located in the province
settlement. It is no surprise, therefore, that the ancestors of
of North Sumatra, 176 km to the west of the provincial capital,
the Batak ethnic minority chose it as their permanent site for
Medan. Lake Toba can be reached by car from Medan within
settlement centuries ago. It was here that their descendants
three hours. By plane, Medan is 40 minutes away from developed into the fi ve ethnic Batak groups; namely, the
Singapore and two hours from Jakarta, the capital city of Angkola-Mandailing, Karo, Pakpak-Dairi, Simalungun and
Indonesia.
Toba. Samosir Island and the Toba lakeside is the site of the
original Batak culture, containing invaluable historical objects
As the largest volcano-tectonic lake in the world, Lake Toba is
and artifacts, art and culture. In fact, Batak culture is still alive
87 km long in the northwest to southeast direction, and has
and present here, preserved in its original form.
a width of 27 km. Located 904 meters above sea level, and
with a maximum depth of 505 meters, the lake is one of the
The unique geographical position of the lake facilitates a
country's important tourist destinations. The natural beauty
range of economically-signifi cant sources of livelihood for
of Lake Toba has been internationally recognized. The lake's
the population, mainly derived from the abundant freshwater
blue waters, gracious residents and fascinating Batak culture
resources and the dense tropical rain forests. The number
draw tourists from all over the globe to the remote destination
of human settlements scattered throughout the Lake Toba
of Lake Toba (Souder 1999). Figure 1 shows details of the Lake
Toba basin.
In the middle of the lake lies the
wedge-shaped island (actually
a peninsula with a very thin
neck) called Samosir Island,
thought to have been created
by subsequent upheavals from
the older lake bottom between
0.6 to 0.1 million years ago.
This spectacular island is one
and a half times larger in size
than the entire Republic of
Singapore, and traveling from
the lake's shore to the island
of Samosir is a great adventure
for visitors.
The Lake Toba catchment area
covers 3,658 km2, of which
the lake surface accounts for
1,103 km2. The remainder of
the catchment area can be
classifi ed as hilly (43%) and
mountainous (30%), with
peaks over 2,000 m above sea
Figure 1. The Lake Toba Basin.

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watershed today is about 366 settlements, mainly in the form
following text provides a summary of organisms identifi ed in
of small villages to medium towns (EIMA, undated).
the lake and other measured parameters.
2. Background
2.1.1 Flora
Emerged macrophytes: Nelumbo nucifera, Nymphaea sp.
Lake Toba is located at the center of a topographic culmination
some 300 km long in North Sumatra. This topographic Floating macrophytes: Eichhornia crassipes, Lemna minor,
culmination is called the Batak Tumor, and runs parallel to
Azolla pinnata, Spirodella polyrhiza
Sumatra Island, with Lake Toba located at its very center.
The 300 km long Batak Tumor is dissected a little west of its
Submerged macrophytes: Patamogeton malaianus, P.
center by the 1,625 long Sumatra Fault which stretches from
polygonifolius, Myriophyllum spicatum, Ceratophyllum
the Sunda Strait to Banda Aceh. The origin of Lake Toba was
demersum, Hydrilla verticillata, Chara sp.
fi rst explained as a volcano-tectonic depression (Bemmelen
1949), and later explained as the result of a series of caldera
Phytoplankton: Amphora, Cocconema, Asterionella, Synedra,
formations combined with faulting activity (Nishimura 1984;
Gomphonema, Orthosira, Navicula, Mastogloia, Pleurosigma,
Hehanussa 2000). The lake covers an area of 1,103 km2,
Nitzschia, Genicularia, Botryococcus, Synechococcus,
Samosir Island has a land area of 647 km2, and the smaller
Anabaena, Oscillaoria
Pardapur Island is 7 km2. The length of the lake is 87 km, and
its circumference measures 294 km.
2.2.2 Fauna
Zooplankton: Cyclops, Cladocera
The lake basin area is surrounded by precipitous cliffs with
elevations ranging between 400 to 1200 m above the lake Benthos: Macrobrachium sintangensis, Brotia costula, Thiara
surface. The latitude and longitude of the lake's water surface
scabra, Melanoides tuberculata, Melanoides granifera,
range between 98°30' E; 3°05' S and 99°20' E; 2°40' S. The
Anentome helena, Lymnaea brevispira, L. rubiginoca,
surface water temperature ranges between 24°C to 27.6°C.
Physastra sumatrana, Corbicula tobae
One single large river, the Asahan River, drains the lake to
Fish: Tilapia mossambica, Aplocheilus pachax, Lebistes
the Strait of Malaka in the east. The lake water surface is recticulatus, Osphronemus goramy, Trichogaster trichopterus,
904 meters above sea level. Using the cable method, Stehn
Channa striata, C. gachua, Clarius batrachus, C. nieuhoffi , C.
reported a maximum water depth of 529 meters in 1939, while
sp., Nemachilus fasciatus, Cyprinus carpio, Puntius javanicus,
recent measurements based on an acoustic echo sounder P. binotatus, Osteochilus nasselti, Lissochilus sp., Labeobarbus
method indicated a maximum depth of 505 meters (Hehanussa
sora, Rasbora sp.
and Takara 2003). This 24-meter discrepancy in the water
depth could be due to the measurement method used for its
2.2.3 Biomass
determination, since the echo-sounding method used in 2003
Table 1. Submerged Macrophytes [g (wet. wt.)/m2].
is considered more accurate than the cable method used in
Station
Potamo-
Myriophylum
Others
Total
1939. During this last (2003) measurement, it was observed
geton sp.
spicatum
that many parts of the lake bottom showed a broad and
Lotung
2,470
130
< 25
2,600
fl at bottom, relatively deeper in the north, while shallower
in the south. The annual lake water level fl uctuation is 1.5
Onan
2,800
150
0
2,950
meters, although a lake level drop of 2.5 m (due to extensive
Runggu
hydropower production) was reported in the late 1980s. The
Parbaloan
1,833
310
520
2,663
water discharge from Lake Toba through the Asahan River was
Urat
measured up to a value of 102 m3/second.
Tongging
1,947
157
< 25
2,104
Lumban
150
1,640
0
1,750
Evaporation is a critical factor in the water balance calculations
Sitorus
for a lake. It was measured at three stations, Palipi, Gurgur
Balige, and Pulau Tao (Anonymous 1990). Measurements at
Pulau Tao showed an average evaporation varying between
2.2

Hydrometeorological Features of the Lake and its
3.5-5.5 mm/day. In contrast, evaporation at Haranggaol was
Drainage Basin
lower because of the wind velocity, temperature and humidity
that differ from the Palau Tao station.
The pattern of wind speed and direction varies for the lake.
During January to April, the wind speed can reach 4 m/s, in
2.1 Biophysical
Features
June 8.8 m/s, and in October 7.1 m/s. If strong winds blow
during June to October, large waves as high as 1.8 m may be
Overall, information on the biophysical features of the lake
induced.
and its drainage basin is scarce, being restricted to several
fi eld measurements conducted in the past. Nevertheless, the
390 Lake
Toba

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Table 2. Climate Data at Balige.
namely whether or not they occurred recently (i.e., less than
Mean Temp.
Precipitation
75,000 years ago) or whether they resulted from a series of
(°C)
(mm)
geological up-doming, blasting, faulting, sedimentation, and
January
19.1
174
up-wrapping that took place since two million years ago.
February
20.1
167
Lake Toba has lately been reported as being the largest caldera
March
20.9
187
lake in the world. This conclusion was based on a report by
April
20.5
193
van Bemmelen, who described the lake as a volcano-tectonic
May
21.0
133
depression. According to van Bemmelen's hypothesis, the lake
history began with the formation of a Batak Tumor, with an
June
20.7
104
oval-shaped, 300 km by 150 km region, located between the
July
21.2
71
present Wampu River in the north, and the Barumun River in
August
21.0
116
the south. The up-doming produced a region with elevations
September
21.0
132
up to 2,000 m, as shown by the tops of such mountains as Mt.
Sibuatan (2,457 m) in the northwest, Mt. Pangulubao (2,151 m)
October
20.4
215
in the east, Mt. Surungan (2,173 m) in the SE, and Mt. Uludarat
November
20.5
188
(2,157 m) in the west.
December
20.2
199
Annual
20.6
1,879
Combined with previous scientifi c studies by Marel (1947), Tjia
and Kusnaeny (1976), Karig et al. (1979), and Hamilton (1978),
Source:
Based on Nontji (1990).
we concluded that the formation of Lake Toba was not a single
Surface water temperatures at various locations (oC):
event, but rather a combination of complex events. It was the
Haranggaol: 27; Tigaras: 27; Tomok: 26; Simanindo: 27; product of a series of events occurring east of the Sumatra
Pangururan: 27; Nainggolan: 27; Parapat: 27; Porsea: 26. Fault. Similar results were encountered in study sites in the
Solar radiation averages 15.7 MJ m2/day.
Lampung area and Maninjau. These series of events are closely
related to the deep-seated occurrence of the Sumatra Fault,
Measurements for pH and chemical oxygen demand (CODCr;
starting about two million years ago.
mg/L), respectively at seven stations along the coast of Lake
Toba: Lotung: 8.4 and 6.7; Situmeang: 7.9 and 6.8; Bukit: 8.4
2.4
The Watershed and Jurisdictional Features
and 9.3; Tongging I: 7.0 and 6.3; Tongging II: 7.9 and 7.0; Onan
Runggu: 7.6 and 7.0; Parapat: 8.2 and 8.0.
The Lake Toba watershed covers an area of 3,704 km2,
embracing a part of the areas of fi ve Kabupaten (district) level
2.3

Geophysical Features of the Lake and its
government administrations (i.e., the Kabupatens), named
Drainage Basin
Tapanuli Utara, Toba Samosir, Simalungun, Dairi and Karo.
Land use (as of 1999) is dominated by scrub (41%), followed by
The geology of Lake Toba has been a challenging topic to study.
forest (22%), paddy fi eld (14%), settlements (11%), grass (8%)
The formation of this lake is the result of mega-volcanic activity
and dry land (4%). Within the Lake Toba region, there are areas
during the Quaternary Era (the last two and a half million reserved specifi cally for conservation purposes, including such
years of the earth's geological history). From a very broad functions as water re-absorption, air pollution control, ground
analysis, this phenomenon was the result of two major plates
stabilization and soil erosion prevention.
colliding, beginning during the Eosen Era (about 65 million
years ago); namely the Indian Ocean or the Australian plates
Kabupaten Toba Samosir, with its twelve kecamatans
in the southwest and the Asian Plate in the northeast. This
(subdistricts) governs the largest portion of the watershed
plate collision produced a long subduction zone, accompanied
(64%), followed by four kecamatans of Kabupaten Tapanuli
by a volcanic chain along Sumatra-Jawa-Nusa Tenggara, up to
Utara (21%), fi ve kecamatans of Kabupaten Simalungun
the Moluccas Islands. In Sumatra, it resulted in a large, long
(10%), one of Kabupaten Karo (3%) and one of Kabupaten
transform fault, the Sumatra Fault Zone (SFZ). This 1,700 km
Dairi (2%). The twenty-three kecamatans of the fi ve districts
long fault is exposed from the Bay of Lampung in the south,
included in the Lake Toba watershed are: Sianjur Mula-
to the Aceh region in the northern end of Sumatra Island. Lake
mula, Harian, Simanindo, Pangururan, Palipi, Onanrunggu,
Toba is not dissected by this SFZ, being located about 20 km
Onanrunggu Timur, Lumbanjulu, Porsea, Silaen, Laguboti
northeast of this fault. In contrast, the Batang Toru and Renun
and Balige of Kabupaten Toba Samosir; Silimakuta, Purba,
Rivers are located and fl ow along the fault.
Dolok Pardamean, Sidamanik and Girsang Sipanganbolon of
Kabupaten Simalungun; Doloksanggul, Muara, Lintongnihuta
Two major explanations of the lake's geohistory suggest it and Siborong-borong of Kabupaten Tapanuli Utara; Merek of
was either (a) the product of one single gigantic explosion,
Kabupaten Karo; and Sumbul of Kabupaten Dairi.
or (b) a product of multiple events. Each of these two major
hypotheses also has smaller sub-explanations. There have
been lively debates on the geological timing of the events;

Experience and Lessons Learned Brief
391

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2.5

The Past Social and Economic Development
2.5.3 Fishery
History and Trends
Fishing is an activity of communities of fi ve kecamatans located
directly on the shoreline. It is undertaken in two ways, mainly
The Lake Toba drainage basin contributes a sizeable share of
fi shing in open waters and fi sh culture in fl oating cages/nets.
the regional, if not the national, economy. The natural beauty
The total catch from the open waters is close to 1,500 tons per
and the richness of Batak culture have given rise to the tourism
year, consisting mostly of six fi sh varieties (Cyprinus, Tilapia,
industries that provide economic benefi t to the communities
Oreochromis, Puntius, Clarias, Ophyocephalus). Since 1996,
living in and around the lake. The unique geographical position
the total fi sh catch has been declining by 5.13% annually,
of Lake Toba preserves many economic potentials for the probably due to an increasing number of fi sh predators, and a
benefi t of the wider range of the lake basin communities, decrease in the natural fi sh sustenance in the lake.
especially as a source of bountiful fresh water and lush tropical
forests, which attract the interest of big industries to invest in
Fish culture in fl oating cages (`karamba' in the local
these areas.
language) is practiced by individual farmers, as well as
private enterprises, mostly foreign investment companies. It
2.5.1 The
Watershed
Population
is suspected that the leftover pelletized feed used in the fi sh
The communities in the Lake Toba watershed are part of culture (by individuals and companies) has polluted the lake
the group of 366 villages within fi ve kabupatens. Based on
water. There were once 1,382 fl oating cages owned by domestic
1999 statistics, the population living in the watershed is and foreign companies, of which 862 (62%) were in Kabupaten
590,861. The lowest population density of 18 persons/km2 is
Simalungun, with the remaining 520 (38%) in Kabupaten Toba
recorded for the sub-district (kecamatan) Sumbul of District
Samosir. The fi sh cages owned by the individual farmers of the
(Kabupaten) Dairi, while the highest density of 355 person/
fi ve kabupatens included in the Lake Toba watershed comprise
km2 is in kecamatan Balige of Kabupaten Toba Samosir. A 1,694 units, mostly located in the Kabupaten Toba Samosir
population density higher that 200 persons/km2 is recorded
(75%). The number of fi sh cages has increased sharply over
in kecamatans along the routes of major economic activities,
the last few years, especially those owned by foreign investors.
especially along the trans-Sumatra highway. There is no clear
There is an estimated 150,000 fi sh cages fl oating in the lake
indication of how it was determined, but the North Sumatra
today. The average size of the cages owned by domestic and
provincial government states that the majority (63%) of the
foreign companies is 6x6 meters, whilst those owned by
Lake Toba basin population belongs in a poor category.
individual farmers averages 2x2 meters.
2.5.2 Agricultural Activities
2.5.4 Tourism
Farming, cash crops production, fi shery, raising animals, From an aesthetic point of view, the attractiveness of Lake
and the tourism industry are the main economic activities Toba lies in its internationally renowned natural beauty. Seen
in the Lake Toba basin. The sector that has proven capable
from almost any angle, it is said that the charm of the lake can
of supporting the livelihood of the population is food crop
make a person become enchanted with a feeling of ecstasy.
production. The agricultural sector remains the mainstay of the
The beauty of each corner of Lake Toba, the array of green hills
majority of people living in the Lake Toba basin. The rice fi elds
that make up the Bukit Barisan mountain range, dressed with
within the watershed cover an area of 41,123 hectares (1999).
adorning waterfalls, are nothing new to this North Sumatra
With an average yield of 5.2 tons of dry rice per hectare, the
tourist attraction. The island of Samosir and the coastline of
basin could reach a production level of approximately 250,000
Lake Toba are the birthplace of Toba Batak culture, and home
tons of dry rice annually. Rice growing is common in all the
of invaluable historical and cultural relics. It is in this place that
kecamatans, but the production centers are in kecamatans the Batak culture is alive and manifested in its genuine form.
Porsea, Lumbanjulu, Balige and Silaen of Kabupaten Toba Modernization has caused population migration and there
Samosir; kecamatan Doloksanggul of Kabupaten Tapanuli are more Batak living outside the region today than those
Utara and kecamatan Sidamanik of Kabupaten Simalungun.
who remained in the vicinity of Lake Toba. Yet, this hometown
During the economic crisis of 1997, the agricultural sector was
remains the core of their identity as Batak in spite of their living
the mainstay for the population, especially when the tourism
in distant places (Lake Toba Heritage Foundation 1999).
industry also declined.
The total population of the fi ve main tourist spots in Lake
The communities living on dry lands grow cash crops, Toba, consisting of Tomok/Simanindo, Balige, Porsea, Ajibata
particularly coffee, coconut, cloves, pili nut and cinnamon and Parapat, is 102,477 persons, about 17% of the total
bark. The total cash crop production area in the basin is 8,640
population of the entire Lake Toba watershed. The tourism
hectares. Coffee is the most important crop, since it is grown in
industry has enhanced the development of 168 hotels from the
all the kecamatans and is to some extent the primary income
traditional Batak home-stay up to four-star hotels. Although no
source upon which the livelihoods of families depend. It is
systematic record was made, the crisis that later impacted the
estimated that coffee growing provides job opportunities for
Indonesian economy caused the number of tourists visiting
more than 27,000 families, with a production of 4,000 tons of
Indonesia to plunge drastically, bringing with it a reduction in
coffee beans annually. Raising animals, especially pigs, cows,
corollary businesses, both in trade and in services.
buffaloes, and poultry is done by families as a side job.
392 Lake
Toba

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2.5.5 Industry
within the basin is only 7,294 persons, a mere 3% of the
The Lake Toba basin industrial potential was revealed since
population of Kabupaten Toba Samosir that lives within the
1982, with the development and operation of PT Inalum, lake's watershed.
an aluminum smelting plant, which needs a great quantity
of electric power produced cheaply from the Asahan River 2.6
Institutional and Managerial Features
hydroelectric generator. PT Inalum is a joint venture company
between the Government of Indonesia and Nippon Asahan Based on Act No. 22 Year 1999 on Regional Autonomy, the
Aluminum Co. Ltd. of Japan, with an initial capital of 411 billion
North Sumatra Province is responsible for coordinating
yen (approximately US$2.4 billion equivalent at the time). certain issues involving two districts or more. In this case, the
The share ownership composition is 41.8% by the Indonesian
management of Lake Toba involves fi ve districts sharing the
government and 58.2% by the Japanese company.
watershed (Toba Samosir, Tapanuli Utara, Simalungun, Karo,
Dairi), plus two other districts located downstream on the
PT Inalum has two headquarters, one at Kuala Tanjung Asahan River but that have indirect infl uences on Lake Toba
downstream of the smelting plant, and one at the power (namely Asahan and Tanjung Balai).
generator at the Asahan River. The company produces 225,000
tons of aluminum per year, while the power generator produces
2.6.1 The Level of Institutional Development and
a total of 603 MW of electricity in two plants (Sigura-gura - 286
Managerial Capacity
MW; Tangga - 317 MW). To produce 450 MW of electricity and
The offi cial institutions that are supposed to be responsible
to propel the eight turbines in the two generating plants, a
for the preservation of the Lake Toba region are the provincial
water discharge of 105 m3/second must be provided by Lake
government of North Sumatra and the local governments of
Toba. At the same time, PT Inalum provides at least 2,500 job
the fi ve districts in Lake Toba region; namely, the BAPEDALDA
opportunities for the local population.
of North Sumatra (provincial-level Environmental Impact
Management Agency) and the BAPEDALDAs of the fi ve
The exploitation of the basin's forests began in 1985, when
districts. To the present time, BAPEDALDAs' activities focus
PT Inti Indorayon Utama (IIU) established a pulp-and-rayon
on the study of the environmental condition of the Lake Toba
processing plant, taking the needed raw materials from the
region, although efforts to coordinate the preservation efforts
forests in six kabupatens (Dairi, Karo, Simalungun, Tapanuli
and initialize partnerships with other organizations have not
Utara, Toba Samosir, Tapanuli Selatan). The capital investment
yet been performed.
for the plant totaled US$40 million, with the plant being
located in the village of Sosorladang, Kecamatan Porsea, 2.6.2 The Level of Interest Group and Community
Kabupaten Toba Samosir. The selection of the plant location
Awareness and Involvement
was made at the central government level. Indorayon is 62%
Environmental problems concern all stakeholders. Cooperation
owned by the Singapore-registered Asia Pacifi c Resources at the local level between the communities, NGOs and other
International Holdings Ltd., which is listed on the New York
environmentalists has to be supported with community
Stock Exchange. The remaining 38% of Indorayon is owned
empowerment, as the foundation of the preservation efforts
by the investing public, cooperatives and a number of in the Lake Toba region. There are a number of successful
shareholders from Finland.
implementations of community programs at the local level,
supported by local government, national and international
The operation of Indorayon was based-on the Joint Decree NGOs, and international agencies such as UNESCO. The pilot
signed by the Research Minister and Environmental Minister,
project of the community-based watershed management,
which gave the green light for the plant's construction and
conducted by LakeNet in association with Lake Toba Heritage
operation in 1986. Indorayon has produced 1.8 million tons
Foundation (LTHF, or in Indonesian, YPPDT), is one example.
of pulp over the ten-year period from 1988 to 1998. It also
Other examples include the cooperation between the
produced 0.25 tons of rayon fi ber as the raw material for BAPPEDA (Planning Board) of the Kabupaten Tapanuli Utara
textiles between 1993 and 1998. Production of these two with the Hanns Seidel Foundation (HSF) in reforestation of
materials was estimated to have consumed around 10 million
critical land with the planting of coffee and cinnamon trees in
cubic meters of wood.
a nine-hectare area in Palipi village; the use of water hyacinth
for cattle food and composting in Pangururan village, Samosir
For its business operation, PT Indorayon secured a total of
Island; and solid waste management of Muara town in the
269,060 hectares of forest concession, covering forest areas in
southern part of Lake Toba. All these activities involve the local
Kabupatens Tapanuli Utara/Toba Samosir (167,943 hectares),
community, and have contributed to the improvement of both
Tapanuli Selatan (41,818 hectares), Dairi (31,627 hectares), the environment and community income.
Simalungun (22,533 hectares), and Tapanuli Tengah (5,139
hectares). It is not clear what portion of the concession area
Over the past few years, UNESCO has supported three local
belongs within the Lake Toba watershed. However, what NGOs in the Lake Toba region (i.e., YAPIDI (the Pijer Podi
is obvious is that the total concession area awarded to PT
Foundation), YES (the Sumatra Eco-tourism Foundation),
Indorayon is four-fold the area of the Lake Toba watershed
and GKPS (the Simalungun Protestant Church Organization)).
forests, while the total number of laborers employed from YAPIDI worked on the `Human resources participatory

Experience and Lessons Learned Brief
393

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development in Sikodon-kodon and Tongging villages' project,
·
Period 1920-1932: Average infl ow discharge to Lake
which focused on micro-credit, organic farming, tree planting
Toba = 110.4 m3/s
and training for women's groups. This NGO has prepared to
get involved in the development of community radio under a
·
Period 1957­1975: Average infl ow discharge to Lake
UNESCO communication project in Indonesia. YES proceeds
Toba = 104.4 m3/s
with its activity in improving the local economics through the
conservation of critical land in Paropo village, a town in the
·
Period 1976­1988: Average infl ow discharge to Lake
northern part of the lake shoreline that was also included in
Toba = 90 m3/s
LakeNet's watershed management pilot project. GKPS made
good progress in its `Environmental preservation in Nagori The water level of Lake Toba has suffered a continuous decline.
Sihalpe village'. The success of the village's tree planting Statistical data from 1982-1998 recorded by the Provincial
activities won the fi rst award in the Kabupaten Simalungun's
Offi ce of the Department of Mining and Energy in North
Environment Day, receiving a badge of appreciation from the
Sumatra indicated a drop in the lake's water level, although
President of Indonesia. Successful outcomes also appear to
perhaps not as great as the community indicated. In January
be occurring with organic farming, cage fi shing and waste 1984, the water level reading was 905.14 m above sea level; in
management in the villages.
September 1998 it was 902.66 m, a drop of only 2.48 m. Even
in July 1998, the water level was as low as 902.28 m, a drop of
There are certainly more activities at the grassroots level 2.86 m.
in Lake Toba region than have been implemented by other
NGOs or community groups. Unfortunately, there is no record
The rainfall data are discontinuous, thereby offering only
of the numbers of active NGOs in the Lake Toba region. poor proof of whether or not there has been any signifi cant
Moreover, there is no adequate documentation or reporting
change. Nevertheless, the indications are that a decline on
system of their programs that could serve as a reference. the order of 10% may have occurred (Anonymous 1990). Other
For these reasons, UNESCO sponsored a national workshop
factors, such as land use changes, may have contributed to an
in early 2000 on `Strengthening communication and local important part to the change.
capacities for community-based participatory environmental
management of Lake Toba' on Samosir Island. This workshop
3.2
History of Lake Degradation
was administered by LTHF, with 20 out of 70 participants
being local NGO representatives. The remaining participants
Pollution from domestic wastes has affected the lake's water
were representatives of universities, LIPI (Lembaga Ilmu quality. In the 1970s, there were no signs of water hyacinth on
Pengetahuan Indonesia, also known as the Indonesian the lake. Since the 1990s, however, they have been observed
Institute of Sciences), local government agencies, press and
fl oating in the Parapat area. The Secchi disk reading of the
international agencies (e.g., UNDP, UNESCO).
water column in the center of the lake in 2001 was 11 m, while
in the Bay of Parapat near the Ajibata harbor it was less than
3. Biophysical
Environment
2.8 meters.
Changes in the Lake Toba region, such as reduction of the lake's
Local government/farmers have introduced "alien species" of
water level and pollution of the lake, directly affect the social
fi sh that can infi ltrate (swim) into the entire lake area. These
and economic situation of the region and, most importantly,
alien species may have to adapt to their new environment.
pose a great threat to the biophysical environment, often seen
Adapting, however, might also mean `will dominate' the
most clearly in localized areas.
ecosystem. An additional problem is cage aquaculture. The
fi sh food poured into the lake increases the water pollution
3.1
Past and Current Conditions
problems. Fish cage culture started to develop in the mid-
1990s and has contributed to the pollution of the lake water.
The fi rst topographic sketch map of the lake region was made
In 2003, extensive fi sh cage culture developments existed
in 1887 by F. van Brenner and van Mechel. In 1909 and 1913,
along the northern Bay of Sigapiton, in Tomok, Simanindo, and
the Porsea and Siruar regions (regions around the Asahan Pangururan at Samosir Island, and in Haranggaol.
River draining the lake) were washed by severe fl oods. In
conjunction with these events, the Batu Bongbong near Siruar
The water quality in Lake Toba during the last few years has
that obstructed the Asahan river outfl ow was blasted away in
suffered obvious deterioration. The oil content of the lake
1915. Next, the Dienst voor Waterkracht en Electriciteit fi rst
water has reached a concentration of 7.5-35 mg/l. The lake
planned in 1918 to construct a hydropower plant in the Asahan
also has suffered biological water pollution, as indicated by
River.
the presence of pathogenic bacteria such as fecal coliform at
levels of 1,000 mpn/100 ml, and total coliform at 20,000 mpn/
Currently only 70 out of 202 rivers discharging into Lake 100 ml of water (Parlagutan Siahaan 1999).
Toba fl ow continuously all year round. According to historical
studies by Sastromijoyo (1990), the discharge from Lake Toba
A water quality measurement study conducted by the
has shown a decrease during three phases:
Environmental Impact Management Agency (BAPEDAL) in
394 Lake
Toba

---

1993, in collaboration with the Bogor Institute of Agriculture,
natural disasters in the form of fl ooding and landslides,
indicated degradation of water quality at several beach
and in the extinction of fl ora and fauna.
areas, particularly the water in the vicinity of Tigaraja-Ajibata,
Tomok and Pangururan (on the island of Samosir), and at the
3.3
Lake and Drainage Basin Resource Confl icts
kecamatan of Balige (in Kabupaten Balige). In 1994, the water
quality in the surrounding rivers exhibited excessive pollution,
Two major industries in the Lake Toba drainage basin have
with a measured biochemical oxygen demand (BOD) of 28 been identifi ed, especially by the communities living around
mg/l BOD (5 mg/l is considered good). It is estimated that this
the lake, as being the most responsible parties for the
level will increase 1.5 times by the year 2010. The pollution
observed decrease in the water level of the lake. The traditional
level in the lake along the shore is evidenced with a BOD value
fi shermen suffer most from the declining lake water level. The
ranging between 6.9 mg/l to 52.2 mg/l, and also estimated to
aquatic plants and shrubs in the shoreline that comprise fi sh
increase 1.5 times by 2010.
habitat wilt and die because of the lack of water. The fi sh go
farther into the deeper water of the lake, making it diffi cult for
It also was found that, in Ajibata and Tomok, oil slicks were
fi shermen to catch fi sh with the traditional hooks or nets. The
spreading up to a radius of 150 meters from the beaches. community fi sh cages do not function under such conditions,
From an aesthetic point of view, this has made the beaches
because they now hang in the open air. Fishermen can catch
less attractive. Although the pollution caused by fuel and one to two kilograms of fi sh daily, in contrast to the previous
oil residues from water transportation does not produce a level of fi ve to seven kilograms. This condition has caused an
major water quality impact, it is estimated that about 14.2
increase in the number of poverty enclaves throughout the
m3 of oil is spilled into the lake annually. There are about lake basin.
190 boats operated in Lake Toba, with an average capacity
of 40 persons per boat. Another indicator suggesting water
3.3.1 Deforestation
quality degradation in the lake is the growth of aquatic Forest clearing by PT Indorayon for raw materials in its
plants, especially water hyacinth, in a number of places. industrial activities has been identifi ed as the main reason
Water hyacinth and other aquatic plants indicate that the for the lake's decreasing water level. As an example, the lake
eutrophication process in the lake water is progressing, community pointed out that the company cleared up to 3,000
especially near the shorelines.
out of 4,000 hectares of pine forest in the kecamatan Ronggur
Ni Huta, Samosir. In its place is young Eucalyptus growth about
The provincial government has identifi ed major problem three to four years old. The community claims that eucalyptus
areas to be considered in the Lake Toba region, as follows
consumes water more greedily; thus, it does not behave like
(Coordinating Board for Lake Toba Basin Ecosystem a water catchment area, rather being the other way around.
Conservation 2003):
This conclusion, however, was denied by the Forestry Research
Center at Pematangsiantar, which instead suggested that
·
Water quality and water balance due to the operation of
broad-leafed plants, such as eucalyptus, with a smaller number
industries and water use by inhabitants -- Due to the
of stomata, are using less water, compared to the needle-
low level of hygienic behavior by the basin inhabitants,
leafed ones (e.g., pine trees). The impact, however, has not
untreated domestic wastes are channeled directly into
been studied comprehensively and deserves further attention
the lake.
in the future. One important aspect to evaluate pertains to the
changes in soil quality due changes in land use.
·
Land use and land tenure -- Land use changes have
been initiated that disregard conservation principles, During its operational decade, Indorayon has a rather
causing the condition of the land to become more critical
poor record in regard to matters concerning pollution and
and more susceptible to erosion. Farming practices that
environmental hazards, including the social-economic aspects
disregarded conservation technology aspects lead affecting the surrounding community. A number of examples
to the production of fertilizer and pesticide residues can be cited, including the leakage from tanks containing toxic
from agricultural activities. Land tenure by the marga
gaseous chemicals in 1993, whereby approximately 5,000
(clan) has made it diffi cult to practice soil conservation
people from the neighboring villages had to fl ee their villages;
measures and sustainable land use.
uncontrolled disposal of waste materials from the plant with
a strong nauseating smell has drawn thousands from Porsea
·
Air pollution due to toxic gas emission from industrial
community to urge that the plant operation be closed down.
plants and smoke produced by forest fi res and trash The downstream communities claim that yields from rice fi elds
burning for land clearing -- During the dry season, forest
and freshwater fi sh culture are continuously declining, because
fi res occur frequently and trash burning is generally the Asahan River on which their economic activities depend is
practiced in land clearing activities for estate crop heavily polluted. The rejection by the local population of the
development, industrial forestry concession, animal smell produced by the factory has temporarily closed the plant.
shepherding, etc. These activities produce air pollution
It is now reducing its total activity to only producing pulp, with
and degrade land and water systems, ultimately causing
a promise to provide better wastewater treatment.

Experience and Lessons Learned Brief
395

---

The Indorayon plant required 400,000 cubic meters of water
lugging heavy containers and machinery, new bridges with
per day for processing, taken from the Asahan River. The used
hundreds of tonnes of capacity were built. The construction
water was then returned to the Asahan River, undoubtedly of the PT Inalum site was accompanied by the development of
mixed with various toxic materials derived from the processing
a new, 200-hectare town called Tanjung Gading, some 16 km
chemicals and substances originating from the wood, as well
from the smelting plant at Kuala Tanjung. Tanjung Gading was
as substances produced from the reaction of both sources of
built from nothing on a swampy land area. With a total of 1,340
chemicals. Of particular concern are toxic substances of the
housing units, Tanjung Gading helped develop the east coast
AOX category (Absorbable Organic Halides), such as dioxin,
of North Sumatra. Presently, the approximately 10,000 people
pentachlorophenol and trichlorophenol. These are the sources
of the new town have been provided employment in a location
of substances in the liquid effl uent (Lake Toba Heritage that used to be secluded and very lonely.
Foundation 2000).
Apart from the aforementioned advantages, the hope for the
Apart from the above-noted toxic substances, various gases
communities around Lake Toba to obtain cheap electricity to
and vapors were released into the atmosphere during the enable them to develop small scale and home industries is
processing of pulp, rayon, and the production of process seemingly diffi cult to materialize. The Asahan hydroelectric
chemicals the majority of which were toxic and foul smelling.
plant was expected to deliver the excess energy to the
Although the most objectionable effect felt by the community
communities of Porsea, Parapat and Balige, in addition to
at that time was the odor, the toxic effect is the most selling it to the state-owned electric company PLN II
alarming aspect over the long term. The majority of gasses
(Perusahaan Listrik Negara Region II), which is responsible
released from the pulping process are collectively known as
for providing electricity for North Sumatra Province including
Non-Condensable Gasses (NCG), especially H2S and MMC Lake Toba region. However, as a result of the decreased water
(methylmercaptan).
level in Lake Toba, the reverse is happening; PT Inalum buys
60 MW of electricity from PLN every month. It has been twenty
3.3.2 Water Use
years since PT Inalum started operation in 1982, and the Toba
In addition to Indorayon, the lake community and other lake
communities remain unchanged with their home economy still
stakeholders also accused PT Inalum hydroelectric as being
dependent on rice cultivation.
another party responsible for the decreased lake water level.
Electricity is the critical element for PT Inalum activities. 3.3.3 Cage Aquaculture
Aluminum smelting needs a great deal of electric power Cage aquaculture in Lake Toba over the last couple of years
generated from the Sigura-gura and Tangga plants, which rely
continues to expand and intensify, with most cages being
solely on the Asahan River, Lake Toba's only discharge outlet.
owned by foreign investors. From an economic perspective,
The problem is that the discharge of the Asahan River cannot
especially considering the recent economic crisis in Indonesia,
be arbitrarily increased without detrimental effects on the it is often viewed as desirable to generate employment,
water level in the lake.
income and food, and support for other activities, while also
increasing local government income. On the other hand, cage
From a technical perspective, to operate eight turbines to aquaculture also has its disadvantages. Wastes from the
generate 450 MW of electricity, the Asahan hydroelectric plant
cages are freely released into the environment, potentially
requires a water discharge of 105 m3/second, which requires
interacting with the entire lake. Intensive cage culture, when
that the lake water level stay at 905.5 m above sea level. In
unregulated, can cause severe environmental problems. Cage
mid-July 2002, the water level was as low as 902.5 m, a critical
farms in lakes and reservoirs are thus vulnerable, both to
level for Lake Toba. To prevent further decreases in water general pollution and to self-infl icted water quality-related
level, the Asahan hydroelectric used only 80 m3/second of problems, in addition to social confl ict due to social inequity.
water, which means idling some of the turbines. The generated
Appropriate regulation, based on a better understanding of
electricity becomes less than 450 MW, thereby causing the
the technical, environmental and socio-economic conditions
ingot production to drop to 180,000 tons per annum, or about
is needed. Participants at several previously-held community
80% of capacity. For this reason, the company claims that it
meetings, especially the boat owners and drivers, questioned
is operating at a fi nancial loss because they are unable to
the existence of `karamba' in fi ve locations of Kabupaten
produce at full capacity.
Simalungun and Kabupaten Toba Samosir. They also estimated
that about 10 tons of fi sh food per day is poured into the lake.
The biggest advantage obtained by the communities
in North Sumatra from the existence of Inalum is the 3.3.4 Domestic Wastes
improvement of the infrastructure which, in turn, encourages
Maintaining a clean environment is one aspect of the Lake
regional development in several support sectors. When the
Toba watershed management, being highly related to the
hydroelectric plant was under construction, the only access
behavior of the people in the surrounding communities. The
for heavy machinery and the giant turbines was through the
way the community treats its environment depends on its
port of Belawan. As a consequence, major improvements to
level of understanding and knowledge. Due to the low level of
the road connecting Belawan and the upper part of the Asahan
hygienic behavior, the lake community channeled household
river were made. To enable them to hold big trucks and trailers
waste directly into the lake, including most of the hotels and
396 Lake
Toba

---

restaurants located in the shoreline of the tourist area. The
To assist the Coordinating Board, the Governor also formed
scene of a family using the lake water for drinking, washing,
a Technical Advisory Committee, with members consisting
bathing and defecating at the same spot is common in many
of representatives from provincial level technical agencies,
areas. From research on Lake Toba water quality in 1993, it was
a number of universities and research institutes, and the
concluded that human settlements are the dominant source
Asahan River Authority. It is hoped that the Coordinating
of pollutants, ranging from 47% to 58% in all four potentially-
Board can help solve the possible confl icts arising from the
polluted zones. The pollution of the lake from untreated different interests among different stakeholders in the Lake
domestic wastes is a household and community issue, thereby
Toba drainage basin. Figures 2 and 3 illustrate the organization
requiring recognition of specifi c situational social and cultural
structure of the Coordinating Board and the Technical Advisory
factors.
Committee. A well-planned, comprehensive program and
systematic implementation of needed efforts in the Lake Toba
4. Management
Environment
basin does not yet exist. The newly-appointed Coordinating
Board for Lake Toba Basin Ecosystem Conservation, however,
4.1
Lake Management Programs and Processes
has formulated a general policy for conservation of the lake
ecosystem, which is intended as a reference and guideline
In recent years, a management committee concept has for the stakeholders in planning and implementing pollution
been suggested several times by many parties, including control and environmental rehabilitation programs. The
the government, private sector, NGOs and even community General Policy for Lake Toba Basin Ecosystem Conservation
groups, all for the purpose of improving management and was formulated on the basis of the Governor's Letter of
environmental preservation in the Lake Toba basin. However,
Decision No. 660/067.K. Whether the programs as formulated
turning this concept into reality has proven diffi cult because
in the general policy are applicable will remain a question for
of differing perceptions and confl icts of interest among the
a certain period of time because a preparatory process also
stakeholders. The establishment of a management committee
is needed, which will itself take time to complete. At the very
in Lake Toba is very important if a coordinated preservation
least, the formation of the Coordinating Board and the general
and collaborated effort among the various parties is to be policy are indications that the regional government's political
achieved.
will hopefully can be regarded as the initial step towards Lake
Toba conservation efforts.
In the absence of such a management committee it will be
diffi cult to develop a common vision among the stakeholders
4.2
Reduction of Lake Stresses
and, as a result, the environmental preservation effort will only
partially work, regardless of who takes the initiative, whether
4.2.1 Legislative
Framework
it is the government, NGO, private sector or the community
Although seemingly small and preliminary, the efforts toward
groups. The impact of the efforts, therefore, will be negligible
environmental preservation of Lake Toba are beginning to
or nonexistent. The nature of the activities, which generally
take place with the issuance of a number of regulations at
comprise a crash program, indicate the absence of a planned,
the central and regional government levels. At the national
sustainable program implementation.
level, Law No. 23 Year 1997 on Environmental Management
serves as the umbrella for the formulation of environmentally-
4.1.1 Establishment of Coordinating Board for Lake
related regional level regulations. This Law stipulates the
Toba Basin Ecosystem Conservation (CBLTEC)
right, the role and responsibility of the community, the
Apart from the pros and cons for establishing a management
authority in environmental preservation, the requirements for
committee, in May 2002, the Governor of North Sumatra, environmental arrangements, solutions to environmentally-
through a Letter of Decision No. 062.05/245/K/2002, related disputes, and investigations and stipulations
named a Coordinating Board for Lake Toba Basin Ecosystem
pertaining to violations and the related consequences.
Conservation. The Board consists of the related government
agencies, both provincial and kabupaten, and the In 1999, an inter-departmental team from the central
representatives of two NGO's, including LTHF at the national
government, led by the Department of Tourism, Art and Culture,
level and Yayasan Peduli Samosir Danau Toba (YPSDT) or `the
completed a draft of a Presidential Decree on Lake Toba Basin
Samosir Lake Toba Foundation' at the provincial level. Two Management. LTHF was invited as a resource and reference
kabupaten level administrative governments are included party. Unfortunately, however, the Presidential Decree failed
among the membership, together with the fi ve kabupatens
to get presidential signature because the draft was met with a
within the Lake Toba drainage basin area. The latter two are
variety of different perceptions regarding its future implications
Kabupaten Asahan and the municipality of Tanjung Balai. when it was introduced to the stakeholders.
The responsibility of the Coordinating Board includes the
formulation of the general policy and coordination of efforts
At the provincial level, the government has issued a regional
and initiatives taken by the different stakeholder components,
Government Regulation No. 1 Year 1990 on Lake Toba Basin
including monitoring of environmental impacts, rehabilitation
Management, which stipulates a prohibition on construction
efforts, and mobilization of community participation.
within a radius up to ten meters from the shoreline.

Experience and Lessons Learned Brief
397

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In order to limit the fast-growing aquaculture enterprises Toba Samosir government will receive US$700,000 per year.
owned mostly by foreign investors, the government had issued
This sum is well above the genuine regional revenue, a clearly
Presidential Decree No. 96 of the year 1998 concerning the
tempting offer in this time of economic crisis.
prohibition of foreign investment for aquaculture in inland
waters.
4.2.4 Construction of Parapat-Ajibata Wastewater
Treatment Plant
4.2.2 Limitations in Water Use
Parapat is one of the busiest tourist centers in the Lake Toba
To counter the accusations of being the main cause for the
region. The relevant Parapat tourist area located on the shores
decreasing Lake Toba water level, PT Inalum indicated it of Lake Toba comprises about 140 hectares. The total resident
was using water within the prescribed quantity limits. The population of about 21,000 people, not including the tourists,
hydroelectric generator is activated only if the water reaches
increases the problems of sewage production from households
a level of 902.40 m above sea level and higher. To determine
and businesses. Almost all the untreated household waste is
this level, PT Inalum built a regulating dam at Siruar, 12 km
discharged directly into the lake. As a result, the quality of the
from the mouth of the Asahan River at Porsea. The Siruar gate
lake water has been reduced to the point that it was necessary
also helps regulate the water level so as not to exceed 905.50
to construct a wastewater treatment plant to address this
m above sea level, at which point many villages along the lake
problem.
shoreline would be inundated. The Asahan Authority, as the
governmental representative, is strictly controlling water use
Development of the sewerage system was necessary because
within the limit of 80m3/second.
of the dense population around the lake, and the number
of hotels and restaurants, using a conventional system.
4.2.3 Changes in the Management of PT Indorayon
The wastewater from households, hotels and restaurants
PT Indorayon later changed its name to PT Toba Pulp Lestari
is channeled to a main wastewater pipe. From that point,
(PT TPL). The name change is in compliance with the central
it is processed and put into aeration ponds. Through the
government decision made in May 2000 to close down the
Department of Public Works, construction of the Parapat-
plant's rayon production, while continuing the pulp industry.
Ajibata wastewater treatment plant began in October 1994,
PT TPL agreed to change its management style to be more
with funds from an OECF sector loan. Most of the constructed
sensitive to environmental concerns and more willing to 1.5 km main and secondary sewer pipes are located at Parapat
work with the local community, by allowing them to practice
town of Kabupaten Simalungun, with a 2,010 m3 capacity
mutually-benefi cial intercropping. PT TPL also is willing to sewage treatment plant with an aerated lagoon system located
accept and support an independent institution with the needed
at Ajibata town of Kabupaten Tapanuli Utara. This facility is
expertise to supervise the use of natural resources. Above all,
equipped with pump lifts at three sites, each with a capacity
PT TPL will set aside 1% of its net revenue from the sales of
of 60 L/s and a hydraulic head of 5.3 m, and with a pressure
its product for the Toba Samosir government, to be used for
pump with a capacity of 60 L/s and a hydraulic head of 41.94
environmental management. If the annual pulp production is
m at one site.
200,000 tons, at a price of US$350 per ton, the Kabupaten
Figure 2. Organization Structure of the Coordinating Board for Lake Toba Ecosystem Conservation.
398 Lake
Toba

---

The Parapat-Ajibata treatment plant was constructed with partnership with Lake Champlain in the United States. The
the capacity to serve 17,400 people, and an additional 4,500
Lake Toba-Lake Champlain Sister Lakes Partnership began in
tourists per day during the high season. Until 2001, however,
1996 with an exchange visit to Indonesia by the coordinator of
only 14 households and 2 hotels were hooked up to the plant,
the Lake Champlain Basin Program (LCBP), at the invitation of
due to a lack of social marketing of the facility.
the Lake Toba Heritage Foundation (LTHF). The program was
coordinated by LakeNet.
4.2.5 Critical Land Rehabilitation Program
The availability of Lake Toba water has been disturbed, The Vermont Agency for Natural Resources (VTANR), in
particularly during the last few decades, due to the disruption
collaboration with LakeNet, applied for and was awarded a
in the hydrologic cycle resulting from the extensive clearing
second grant of US$40,000 through a CSG/US-AEP initiative
of forest cover around the lake. Thus, a priority action for the
to bridge exchange programs into an implementation phase.
rehabilitating the environmental conditions is the reforestation
With this bridge funding, the project partners conducted a pilot
of the basin, which includes 50,192 hectares of highly eroded
program to demonstrate ways of developing and implementing
(critical) lands (29% of the watershed area). The North a community-based watershed action plan. The implemented
Sumatra provincial government has a program to rehabilitate
project activities include:
the vegetative cover of over 104,570 hectares of critical lands
in the Lake Toba watershed. The program is divided into ·
Selection and training of 10 environmental cadres to
two parts, one being the rehabilitation of 50,192 hectares
serve as local leaders on environmental initiatives
into complete forest cover, comprising production and
related to Lake Toba;
conservation forests. The other part is the replanting of 54,378
hectares of critical lands with perennial crops (estate crops
·
A two-week in-country study tour for environmental
and mountain horticultural gardens). The perennial crops have
cadres in East and Central Java to observe and study
two advantages; namely, serving as ground cover and also
community mobilization efforts and commitment-
increasing land productivity to improve farmer's incomes. It is
building in constructing, fi nancing, managing and
hoped that, through this program, the critical lands will turn
maintaining low-cost community-based sewer systems,
green again, thereby also increasing the soil water-holding
a low-cost composting technique in Malang, and the
capacity, reducing run-off, erosion and sedimentation, and
harvesting and utilization of water hyacinths in Cirebon
eventually improving Lake Toba's water quality and quantity
and Yogyakarta;
and at the same time maintain soil fertility in the farmlands.
·
Completion of clean lake activities along 5 km of
4.2.6 Community-based Management of Lake Toba
the lake's shoreline in fi ve communities. More than
In 2001, LakeNet partnered with the LTHF to implement a
770 people participated in these activities, some of
pilot project on community-based watershed management
which involved strenuous labor and diffi cult working
program for Lake Toba. The one-year demonstration program
conditions;
was conducted as part of a six-year old sister lakes exchange
Figure 3. Lake Toba Technical Advisory Committee.

Experience and Lessons Learned Brief
399

---

·
Training in environmental education and awareness for
given that improved sewage systems, invasive species
teachers from six districts in the Lake Toba area, using
reductions, trash reduction and improved local capacity
a specifi cally developed `hands-on learning' Water
will improve Lake Toba and community health, as well as
Module;
facilitate poverty alleviation; and,
·
Formulation of community action plans through ·
The publication of information on the Lake Toba Online
community meetings involving 188 community members
website and LakeNet's electronic forum of more than
in identifying and discussing environmental problems
900 members involved in lake activities around the
and concerns of Lake Toba; and,
world.
·
An awareness campaign involving the distribution In terms of stakeholder participation in this project, almost
of 25,000 copies of an information brochure in the 1,000 community members were involved in the clean lake and
Indonesian language to promote environmental community meetings aimed at the formulation of community
awareness.
action plans. Participants included boat operators, farmers,
fi shermen, small traders, vendors, housewives, and hotel
The most important results of the implemented actions owners. The ten environmental cadres were chosen from
included:
grassroots participants and were central to all activities.
Women were specifi cally targeted to be involved in the
·
The lake cleaning activities by volunteers, including the
community meetings. The fact that 33% of the participants
removal by hand of large patches of water hyacinths,
were women is a signifi cant achievement in this regard, due
opened up landing areas for local fi shing and ferry boats
to the very paternalistic local culture. The women proved to
that had been inaccessible for almost three years, and at
be very active and outspoken in the community discussion,
the same time reducing the invasive plant populations;
making signifi cant contributions to the local action plans.
Many community members made in-kind contributions to the
·
The study tour and on-the-job training (through clean lake activities. Government offi cials from the local Police
participation in community meetings, clean lake and sub-district (kecamatan) offi ce were involved in the clean
activities, teacher's training and brochure distribution)
lake activities. The Mayor of the City of Malang and his staff
resulted in effective in-country transfer of knowledge provided all of the facilities needed during the study tour of
to the environmental cadres. Many have demonstrated
the environmental cadres from Lake Toba. The Governor of
their ability to help implement and sustain activities North Sumatra gave his support to the environmental cadres
begun during this project;
before their departure on the study tour. Other NGOs at the
national and provincial level also took part in the project. The
·
Teachers and representatives of three universities in Hanns Seidel Foundation (HSF), for example, provided the
the Lake Toba region gained important environmental
trainers and the environmental education training materials
knowledge and educational materials;
for schoolteachers. Three researchers involved in formulating
an environmental education book for the elementary school
·
Detailed resource inventory maps and action plans were
children trained the teachers from the six districts of Lake
completed in fi ve communities, using a participatory Toba. Local universities surrounding Lake Toba sent their
approach;
representatives to the three days teachers' workshop.
·
New Lake Toba issues were identifi ed for the fi rst time,
There is a big potential for community participation in the
including the increase in the number of fi sh farms on the
efforts to sustain Lake Toba and its drainage basin. The
lake and their potential impacts on its water quality;
critical point lies in determining where and how to improve
the awareness and understanding about different aspects
·
Citizens and the community as a whole gained increased
of ecosystem sustainability, and to bridge the community
awareness of lake problems by participating in awareness with real action toward sustaining the lake
community meetings and clean lake activities;
ecosystem, which at the same time renders benefi ts for
improving the social economic condition of the community.
·
Boat operators gained awareness of their role in This goal translates into an integrated program involving
environmental stewardship of Lake Toba, as a result of
social economic improvement and sustainable environmental
meetings with this important stakeholder group;
development. Where community members from varying
backgrounds, including schoolboys and girls, hotel owners,
·
Local partners learned the benefi ts of involving people
fi shermen, traders, farmers, etc., join together in various
and working with the community in planning and environmental activities such as re-greening, garbage
implementation activities;
collection and clearing water hyacinths, and environmentally
sensitive farming practices are all positive examples of the
·
If fully implemented, the project can be expected to have
potential to increase community awareness and involvement.
long-term social, economic and environmental impacts,
400 Lake
Toba

---

4.3 Enabling
Environment
At the provincial level, there are the Offi ces and Agencies of
Forestry, Estate Crops, Agriculture, Marine and Fishery, Mining
4.3.1 The Critical Policy and Institutional Framework for
and Energy, Tourism and Culture, Planning Agency (BAPPEDA),
Management of the Lake
provincial-level Environmental Impact Management Agency
Before the establishment of the Coordinating Board, the (BAPEDALDA), Meteorology and Geophysics, PDAM (Local
Lake Toba region had been proposed by UNESCO to be Government Water Company) and the River and Lake
designated as a Biosphere Reserve, focusing on three main
Transportation Agency.
activities: conservation of bio-diversity; economic and social
development; and preservation of associated cultural values.
At the kabupaten level, the head of administration (Bupati) is
With this biosphere reserves status, it was expected that directly involved, assisted by the related agencies in his realm
Lake Toba would receive international attention and invite of responsibility (BAPPEDA, BAPEDALDA, etc).
international participation in its development and preservation.
According to the Act No. 24, 1992 regarding Spatial Planning,
Although several agencies in each level of the government
the Biosphere Reserve designation is identical to the have been undertaking efforts related to sustaining the
designation of `Special Region', a region with prioritized environmental conditions in Lake Toba, the Coordinating
spatial planning. Designation of a region as a `Special Region'
Board has acknowledged the weakness of coordination
requires a Presidential Decree, and up to the present time, this
among the agencies within one single kabupaten as it is with
proposal has not been realized for lack of the Decree.
one province, between the province and the kabupaten and
between the government and the community. In fact, it is this
The general policy formulated by the Coordinating Board sectoral approach that results in the program of one agency
has resulted in the development of a comprehensive being alien to the mission and priorities of other agencies,
and environmentally sensitive Lake Toba drainage basin which highlights the need for establishing the Coordinating
management master plan becoming a priority. The Board.
Coordinating Board must ensure that the master plan
suffi ciently accommodates the aspirations and concerns of all
In the meantime, compared to other Lake Toba stakeholders,
lake stakeholders. Since the enactment of regional autonomy,
the community participation at the grassroots level for
each kabupaten reserves the authority to manage its region,
environmental sustainability of the lake and its basin is
and each is trying its best to reach the highest possible genuine
generally better, although they must be accompanied and
regional revenue target. For this purpose, all fi ve kabupatens
facilitated by NGO activities. As previously discussed in the
tend to grant permits to capital investment, with forest logging
section on the grassroots level programs, although they may
being the main resource, followed by fi shery and estate crops.
seem small, they have produced tangible results in sustaining
With the union of the fi ve kabupatens into a coordinating the Lake Toba basin ecosystem.
board, it is hoped that a common vision and commitment can
be reached and, for the sake of maintaining the sustainability
Thus, there is a big potential for community participation in the
of the Lake Toba basin ecosystem, that they would refrain from
efforts to sustain Lake Toba and its drainage basin. The critical
using the lake's natural resources in an abusive manner.
point lies in determining where and how we can improve
awareness and understanding about the various aspects of
4.3.2 Stakeholder Involvement
ecosystem sustainability, and in bridging community attention
The Lake Toba drainage basin is not only home for 590,861
with real action directed toward sustaining the lake ecosystem.
local watershed inhabitants, but also a promising area that
This also will render benefi ts for improving the social economic
attracts outsiders, domestic as well as foreign, to invest in
condition of the community. Thus, an integrated program
business undertaking. Thus, all interested parties related between social economic improvement and sustainable
to Lake Toba comprise its stakeholders, including the environmental development is necessary. A favorable
government, the private/business sector, and grassroots indication regarding the potential for community attention is
level communities. The community, however, is the main lake
the fact that community members from varying backgrounds,
stakeholder, since anything done in the drainage basin can
schoolboys and girls, hotel owners, fi shermen, traders,
have direct consequences on the lives and livelihoods of the
farmers, etc. have joined together in various environmentally-
people living in the Lake Toba watershed.
related preservation activities such as re-greening, garbage
collection and water hyacinth clearing, and environmentally
At the national level, there are at least eight institutions sensitive farming practices.
interested in this area, especially those with authority to give
approval to foreign investment, namely the Departments of
4.3.3 Monitoring and Research Capacity
Forestry, Agriculture, Tourism and Culture, Finance, Marine Routine monitoring (e.g., rainfall) is performed by the Agency
and Fishery, State Ministry for Environmental Affairs, Asahan
for Meteorology and Geophysics, which maintains 11 rainfall
River Authority, and the Agency for Studies and Application
measuring stations throughout the basin. The water level
of Technologies, which played a signifi cant role in the initial
fl uctuations in the lake are monitored by the provincial offi ce
decision on PT Indorayon.
of the Department of Mining and Energy. In the meantime,
rehabilitating and maintaining sustainability of the Lake Toba

Experience and Lessons Learned Brief
401

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ecosystem is a complicated, multi-dimensional problem. The
Although there is not yet any specifi c commitment and
root causes of the problem vary extensively, and the problems
confi rmation regarding fi nancing, there are at least two funding
have been piling up for several decades. A number of research
sources available for Lake Toba ecosystem preservation. For
investigations have been conducted, including studies on example, the North Sumatra government administration and
water quality, analyses of the suitability of various plant DPRD (Provincial Parlilament) have tried to obtain clarifi cation
species, identifi cation of plant species diversity, and a fi eld
regarding the annual fee for Lake Toba conservation paid by
trial on the application of environmentally sensitive concepts
PT Inalum to the government through the Ministry of Finance.
in land use. But all these research efforts only partially Up to now, it is not clear how these funds are to be used. The
address the problems, being focused only on some specifi c
accumulated fee paid from 1982 through 1999 has reached a
aspects. Further, the agencies conducting the research tend
total of US$59 million. Further, according to the North Sumatra
not to share their results with other agencies. There is yet no
BAPEDALDA, PT TPL has paid the local community development
solid and comprehensive research project covering the major
foundation (Toba Samosir Community Development
environmental and concerns regarding Lake Toba and its Foundation) the funds initially agreed upon.
drainage basin. Some of the research/studies that have been
conducted include the following:
The Coordinating Board for Lake Toba Basin Conservation is
unable to identify the level of funding available for maintaining
·
Study on lake water quality by the BAPEDAL, in the sustainability of the lake's drainage basin. Rather, it only
collaboration with the Bogor Institute for Agriculture,
indicates that the potential funding sources would be the
1993;
Central Government Budget (APBN), Provincial Government
Budget (APBD), Kabupaten Budget (APBD), national and
·
Study on disturbances to the Lake Toba basin ecosystem
international NGOs, and other non-binding sources.
by the BAPEDALDA, in collaboration with the Faculty of
Geography, University of Gadjah Mada, 2000;
4.3.5 Global Network
Lake Toba has greatly benefi ted from the Sister Lakes
·
Study on the suitability of several perennial trees to Partnership with Lake Champlain in the State of Vermont
critical lands in the Lake Toba watershed, and nutrient
in the United States. In 1996, a delegation from Lake Toba
depletion in soils under eucalyptus stands, by the consisting of government representatives, the business and
Forestry Research Center Pematang Siantar;
industrial sector and the university visited Lake Champlain
to observe and learn the concepts of integrated management
·
Study on land rehabilitation and soil conservation by
implementation of a lake drainage basin in a systematic and
North Sumatra Provincial BAPPEDA, in collaboration economically-profi table manner. The delegation from Lake
with Community Development Research Division, Champlain also visited Lake Toba in 1999 to observe the
University of North Sumatra.
potential and the problems faced in the Lake Toba drainage
basin. The "people to people" exchange has proven to be a
4.3.4 Past and On-going Financial Investments
very effective learning medium.
Up to now, no specifi c records are available regarding the
extent of capital investment for Lake Toba preservation 5. Lessons
Learned
efforts, since such programs are implemented singularly and
in isolation. However, there are a few small investments that
5.1

Stakeholder Involvement is Key to Program
could be found in the available records, including:
Design, Implementation and Effective Action
·
In 1996, UNESCO, in cooperation with the Government
A new management paradigm for Lake Toba drainage basin
of Denmark through DANIDA, supported the publication
conservation, particularly in the context of coordination among
of the newsletter `Pesan Danau Toba' (Message from stakeholders, covering community groups, NGOs, the private
Lake Toba) (Parlagutan Siahaan 1999) as a vehicle for
sector and the government, must be created and strengthened.
information exchange to accelerate the environmentally-
With an integrated and coordinated approach, it is anticipated
friendly development of the region. LTHF administered
that a synergetic effort could become reality. This will result in
the publication of 1,500 copies of the monthly bulletin;
establishing common priorities, mutual understanding in the
approaches to be applied, and prevention of duplication and
·
Lake Toba activities have received fi nancial support from
overlapping of sometimes confl icting activities. Achievement
the U.S. government. Starting in 1996, the investment of
of the above will help make a sustainable development process
U.S. federal funds over a six-year period totaled just over
in the Lake Toba drainage basin become a reality.
US$400,000, with matching funds from other sources in
the U.S. totaling approximately US$220,000. These The establishment of the Coordinating Board at least highlights
funds were used in a series of projects on Lake Toba
the political will of the North Sumatra provincial government in
under the sister lakes partnership between Lake Toba
its effort in managing Lake Toba. Most of its members are ex-
and Lake Champlain, including program implementation
offi cio, although several represent regional and national level
at the grassroots level.
NGOs. Being newly appointed, the effectiveness of the Board
402 Lake
Toba

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has yet to be demonstrated, which may take a considerable
5.2
Capacity Building on Community Participation
period of time. In the long run, however, the Coordinating Board
could become a very strategic institution if it can maintain
Community participation in lake management is essential,
a continuing community development effort and reconcile not optional. A community-based approach offers the most
the different interests of the various stakeholders, thereby promising strategy for sustainable management of Lake Toba
allowing them to work synergistically together, including and its watershed. Whether planning a wastewater treatment
fi ltering out any exploitative conduct in natural resource-based
facility, rehabilitating critical land through tree planting,
economic activity. The Coordinating Board must be able to introducing environmentally-sound farming, solving water
maintain continuation in building synergism, coordination supply problems, implementing measures to improve water
and sustainable development of Lake Toba drainage basin, quality, or trying to change the personal hygiene behavior
including regular monitoring, in order to allow timely corrective
of people in the community, the most effective programs are
measures if any deviations in the development implementation
typically those which involve citizens and stakeholders from
become necessary.
the very beginning. This is perhaps one of the more useful
lessons to be learned from community-based pilot projects,
The involvement of environmental stakeholders at all levels
especially when one considers the investments in wastewater
is indispensable, one being the grassroots community. infrastructure and other environmental projects on Lake Toba
Management of the Lake Toba watershed is impossible and elsewhere in Indonesia, whereby a facility is usually built,
without the involvement of the communities living in it. The
or a plan developed, without the input or involvement of the
adoption of participatory approaches into the development community. More often than not, lack of a community-based
projects in Indonesia has been increasing over the past several
approach will result in facilities that do not operate properly
years. During the past three decades, the government of and plans that are not effectively implemented.
Indonesia has used a centralized, top-down approach in many
development sectors, which resulted in many abandoned Unfortunately, even when the provincial and district
infrastructures and facilities with large investments. The government staff is committed to a participatory approach, as
political changes in 1998, however, created a greater stated in the General Policy for the Lake Toba Basin Ecosystem
autonomy for the provincial and local governments, thereby
Conservation document, they may not have the capacity to
facilitating a greater chance for direct community involvement
implement it. Lack of incentives and skills among government
in development activities.
staff to encourage them to adopt a participatory approach is
the main reason for this problem. If government staffs are not
Field observations have convinced many, including provided with the necessary knowledge, skills and incentives
development practitioners, that the participation of the to work in a participatory way with local communities, their
community in the decision-making process greatly infl uences
willingness and ability will be severely hampered. Government
the implementation and sustainability of projects. The staffs often are less qualifi ed to work in a fl exible, responsive
participatory approach is an effort to solve common problems
manner in facilitating community action. Thus, they have
through the use and building of community knowledge less capacity to develop participatory forms of stakeholders
regarding matters related to the problems. A dynamic, working together; thus, their decisions tend to be made in a
demand-based and change-oriented participatory approach more top-down manner, involving only the village leader(s) or
can improve the concern and capability of communities by a small group of elite members of the community. Furthermore,
giving them skills to analyze and solve their own problems. The
the standard government system for planning, transferring and
participatory data and information collection and inventory accounting for funds means those government personnel do
process by the community stimulates the sense of belonging
not have the time, authority or resources to modify the program
and involvement in the implementation of the plan they to suit the changing needs of the community. Workshops and
themselves developed.
training in the proper mechanism of community participation
is necessary not only for the local community itself, but more
Community-based activities with a signifi cant participatory importantly for government offi cials.
approach will hopefully bring into the policy development
process the voices of an often-excluded principal stakeholder
5.3

Planning Must be Supported by a Strong
group -- the community. From the experiences of community-
Research and Monitoring Program
based project implementation in the Lake Toba region,
policymakers can draw insight regarding what works and why,
To enable development of a workable, comprehensive, and
and use that knowledge to create strategies to bridge the gap
widely-accepted Lake Toba basin management master plan,
between national or regional policy and local practice. Through
and to turn a common vision into reality, it is necessary to
the application of dialogical approaches combining bottom-up
build a thorough research base covering a wide range of
and top-down program formulation practices, it is expected
disciplines, as well as support for complete and accurate data
that community commitment in Lake Toba basin conservation
obtained from a continuous and regular monitoring program.
program implementation can be developed and improved.
The availability of such data would allow the implementation
of Lake Toba basin conservation activities be undertaken
in a holistic approach covering every angle of the relevant

Experience and Lessons Learned Brief
403

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problems, thereby also facilitating the success level and its
5.5
Environmental Awareness and Education
impact on all lake stakeholders.
Community members are often the best infl uencers and
As an example, in the general policy for Lake Toba basin communicators for change. People tend to be more easily
ecosystem conservation, there is a specifi c mention of zoning
convinced by their neighbors' experiences, tending to trust
of cage aquaculture as one component of the master plan. For
those they live with more than outsiders. When a new facility,
this reason, there is a need for an extensive, in-depth study
such as the community-based wastewater treatment plant,
of this issue. Up to now, there has been no study conducted
is introduced, its pros and cons must be fully understood
on the environmental impacts of the vast growing cage before it can get readily accepted. Explanations by outsiders
aquaculture on Lake Toba. The lack of accurate and reliable
may serve to inform people, but the community tends to
data is obviously a hindrance to formulating a realistic program
better trust and accept such information as being true only
to address this issue. At this time, virtually every attempt for
when a relative, neighbor or a local leader confi rms it. Many
rehabilitation or preservation works in Lake Toba has had to
of the ten environmental cadres selected from the local
start from scratch (e.g., visiting various government agencies
respective community included in the pilot project have
in order to collect the needed basic data). It often happens that
demonstrated their ability to help implement activities.
data users do not know where to fi nd the basic data they need
However, their sustained willingness to be a community
and, if by luck the data were available, the users are not sure
motivator after a project is complete cannot be guaranteed,
of their reliability or accuracy the data. There is no assurance
since it often requires a highly-dedicated individual. A more
about data reliability in statistical terms (i.e., data collection
thorough selection process for the environmental cadres as
technique), as well as in terms of the non-technical aspects.
the indigenous potential change agents is needed. At least
Thus, the establishment of an information center to collect,
three months or more is typically necessary to devote to
arrange, update, verify, process and disseminate the necessary
the exploration of dedicated, committed and trustworthy
data to the parties in need of accurate data/information is
indigenous potential change agents. A scheme of small
urgent. The proposal for Lake Toba Science Center, which will
incentives is important to support the environmental cadres for
function as an education and environmental research center
the time and energy they devote to promoting environmental
in the Lake Toba area, is not only important for the future in
awareness and initiatives.
assisting educational institution and developing community
awareness in environmental aspect, but also could function as
Behavior change does not happen until people realize or
a data clearing house for Lake Toba.
experience the benefi ts that can result from the change.
Behavior can be said to have changed only when newer
5.4

Integrate Science and Policy throughout the Lake
behavior patterns replace older ones consistently and are
Management Institution
sustained over the long term. Although measuring behavioral
change as a result of environmental education of schoolchildren
Research and monitoring are essential components, if the can certainly take a very long time, the results can be far more
changes occurring in the lake are to be properly recognized and
effective and sustainable. Training elementary school teachers
understood. Apart from the fact that very little has been done
on practical environmental education has been expanded to
in terms of science and social research, the few works that
cover more than a hundred teachers and community leaders in
do exist were not suffi ciently published, let alone being used
the Lake Toba region and should be continued.
directly by policymakers or grassroots-level communities. The
research community, especially science research, tends to be a
The implementation of environmental education is a very
closed community. Although the reports of scientifi c fi ndings
appropriate means for raising awareness at the elementary
from many costly research projects may have found their way
school level, because the subject is fi lled with social, cultural
into libraries, they should have been better used as input for
and ethical norms. Environmental education is urgently needed
policymakers. On the other hand, policy- and decision-makers
in their early years to help students develop an attitude of
also seem to ignore scientifi c advice when they are formulating
caring for the environment and for avoiding behaviors that
decisions. Thus, it is necessary to build a communication can hurt the environment. Environmental education also
bridge between the scientist and the policy-makers, especially
can help students begin to realize that they themselves are
in the context of relevant scientifi c advice and the provision of
an inseparable part of the environment, and to feel a sense
feedback in the form of what could or should be done or not
of stewardship and moral commitment to environmental
in solving a problem. Communication between researchers conservation. Environmental education at the elementary
and the grassroots community also should be established school level is not an independent subject at the current time.
because the community also needs scientifi c information Rather, it is generally taught as part of other subjects, such as
in order to better understand the ecosystem in which they
social science, natural science and family welfare. As a result,
live. Accordingly, scientifi c terms and language level must environmental awareness tends to be low among school-age
be simplifi ed, since scientifi c information is frequently too children. At later stages, mainstreaming the environmental
technical to be understood by policy-makers, let alone the education into the local curriculum of environmental education
grassroots-level people.
would be a positive effort in facilitating the health of Lake
Toba.
404 Lake
Toba

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5.6

Environmental Sustainability, Economy and
at 10th International Conference on the Conservation and
Poverty Alleviation
Management of Lakes, Chicago, United States, 22-27 June
2003.
The economy and environment are two inseparable aspects,
especially natural resources-based economic activities. The Karig, D.E., G.M. Suparka, and P.E. Hehanussa. 1979.
economic aspect can be viewed from the local, regional, "Structure and Cenozoic Evolution of the Sunda Arc in North
national and international perspective. The business sector Sumatera Region." Geol. and Geoph. Inv.of Cont. AAPG, 1979,
in the basin, viewed from the regional/national context, is United States.
related to manpower and, from the international context, is the
international capital share. The environmental aspect is related
Lake Toba Heritage Foundation. 1999. Newsletter (April), p. 6.
to how to sustain the Lake Toba drainage basin as an income-
generating source for local population and attractiveness to
Lake Toba Heritage Foundation. 2000. The impacts of PT Inti
the international community. Since the implementation of Indorayon Utama's Operations on the Environment of Lake
environmental regulations in Indonesia is still very weak, it
Toba.
is essential that the law enforcement apparatus be improved.
Proper law enforcement would facilitate the possibility that
Nishimura, S., E. Abe, J. Nishida, T. Yokoyama, A. Dharma,
everyone could work and invest capital safely, and that justice
P.E. Hehanussa, and F. Hehuwat. 1984. "Gravity and
in the community could be established.
Volcanostratigraphic Interpretation of Lake Toba Region, North
Sumatra, Indonesia." In Tectonophysics. Elsevier Science:
The links between environmental sustainability and poverty
Amsterdam. p. 253-272.
alleviation in the context of sustainable development also are
important, particularly for natural resource management. This
Nontji, A. 1990. "Review of the Limnology of Lake Toba." Paper
is because the very poor often contribute to environmental
presented at International Conference on Lake Toba, 1990,
degradation when pushed to the margins in order to Jakarta.
survive. More important, environmental degradation from
various aspects of industrialization and growth have had Parlagutan Siahaan. 1999. Pesan danau Toba (Message from
very adverse effects on the poor; air and water pollution Lake Toba bulletin). September 1999. p. 8.
affect their health, soil erosion weakens their productive
capacity, and land encroachment restricts their access to Sastromijoyo, S. 1990. Some Hydrological Aspects of Lake
traditional productive assets. Because poverty is seen both
Toba. Inst. of Hyd. Eng. Dept. of Public Works, Bandung.
as a consequence and cause of environmental degradation,
improvements in environmental quality should help reduce Souder, A. 1999. "The new faces of development assistance."
poverty and vice versa. Poverty alleviation, however, requires
US Council of State Government News, June/July 1999. p. 14.
a multidimensional approach. The root causes are complex--
including for Lake Toba--and must be well understood in Tjia, H.D. and K. Kusnaeny. 1976. "An Early Quaternary Age of
order to fi nd the appropriate alternatives for integrated and
an Ignimbrite Layer, Lake Toba, Sumatera." Sains Malaysiana
structured solutions.
5:67-70.
6. References
Disclaimer
Anonymous. 1990. A Study of the Decline in Water Level The fi ndings, interpretations and conclusions expressed
of Lake Toba, Indonesia. Report prepared by the Overseas in this report are the views of the authors and do not
Development Administration, UK for BPPT Teknologi, Jakarta.
necessarily represent the views of The World Bank and its
Board of Directors, or the countries they represent, nor do
Bemmelen, R.W. van. 1949. The Geology of Indonesia, Vol. 1a.
they necessarily represent the view of the organizations,
Government Printing Offi ce: the Hague, Netherlands.
agencies or governments to which any of the authors are
associated. Also, the colors, boundaries, denominations, and
EIMA
(Environmental Impact Management Agency) classifi cations in this report do not imply, on the part of The
(BAPEDALDA) of North Sumatra Province. (undated). General
World Bank and its Board of Directors, or the countries they
Guidance for the Control and Management of Lake Toba represent, and the organizations, agencies or governments to
Region.
which any of the authors are associated, any judgment on the
legal or other status of any territory, or any endorsement or
Hehanussa, P.E. 2000. Lake Toba, a Multiple Caldera acceptance of any boundary.
Depression, North Sumatera, Indonesia. Report of Suwa
Hydrobiological Station, Shinshu University, Japan.
Hehanussa, P.E. and K. Takara. 2003. "New Findings of a Step-
Like Flat Lake Bottom, Lake Toba-Indonesia." Paper presented

Experience and Lessons Learned Brief
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