Lake Tondano is the "heart" of North Sulawesi, representing the source of water supply for a large proportion of the population, is also a source of water for gravity irrigation of crops - mainly rice and fish is an important source of production and the center of cage-reared fish of northern Sulawesi. Equally important has been his role in electric energy in a cascade of dams under the lake. Tondano lake basin is a priority for the importance of water conservation and maintain good water quality in the lake.
The Tondano watershed has area was measured by the project at 57, 850 ha according to the 2003/5 study by Mott MacDonald Praha. The study indicated that there were 17 503 ha critical lands identified according to the methodology used in 2005 and 2010, that is 30,26 % of total area.
In Indonesia, a major source of serious erosion and catastrophic flooding extent deemed just degraded critical area. According to the local Ministry of Forestry (2001 and 2002) in Indonesia from 22 to 36 major river basins, where a critical mass of degraded areas are more than 20% of the watershed. Tondano River Basin lakes are amongst the most critical watershed.
Significance of North Sulawesi -Environmental Security Issues of North Sulawesi
The Tondano Lake Watershed in North Sulawesi is one of the most degraded areas in Indonesia. North Sulawesi is one of the key strategic hubs of Indonesia and Southeast Asia. It lies on crossroads between the west and east Indonesia, crossroads between Indonesia, Philippines and Malaysia and commands straits leading to the Celebes Sea and Moluca Sea. Celebes sea and Moluca regional seas lie on a strategic communication lane that is used by big powers nuclear submarines during the transit between the Pacific and Indian oceans. It lies in an area particularly rich in marine fishery resources on an old sea trading route with oriental spices. It is also a major transportation hub within the BIMPEAGA ADB programme of sea, air, road and sea transportation infrastructure development areas of the Asian Development Bank.
Involvement of the Czech Republic in this region opens up an area highly significant for Czech economic strategy and is significant for the new EU members states. It can open up potential access to markets with high demand on transportation, water resources, energy, alternative energy and agro processing technologies. The study also proves that involvement of EU central European countries in the ASEAN region can be beneficial for both regions.
North Sulawesi is important for following strategic reasons:
- lies at the crossroads of marine shipping lanes connecting the Pacific Ocean and Indian Ocean
- Lies at the crossroads of marine shipping lanes and fish migration (tuna being a strategic marine resource) routes between the South China Sea and Sulawesi Sea/Indian Ocean
- Forms the cross boundary hub between the Philippines, Indonesia and Malaysia
- Forms the cross boundary hub on the route used by the Abu Sayaf extremist Group and Southeast Asian Al Qaeda affiliates for illegal transboundary movement of extremist groups between the Southern Philippines (Mindanao) and low-intensity conflict zones in the Moluccas (Ambon) and Central Sulawesi (Poso), as well as for infiltration into Malaysian territory (Sabah)-from where movement to other points in the region takes place.
- Forms the cross-boundary hub on the route used for weapons smuggling between the Southern Philippines and Indonesia
- Lies in an area used for illegal fishing by Philippine, Malaysian, Taiwanese, South Korean, Chinese (Hong Kong), Vietnamese, Japanese and possibly Russian trawlers
- Suffers from illegal fishing by cyanide and explosives in the coral reef areas
- Lies at the crossroads of marine shipping lanes connecting and accessing major gas reserves in the Eastern Indonesia sub regional seas
- Represents one of the most politically-stable areas of Southeast Asia and Indonesia
- An example of ethnic and religious harmony between the local Christian population (80% majority) and Muslim newcomers (post-independence arrivals)
- Represents a distinct cultural and historical heritage for Indonesia and Southeast Asia
- Represents a key trading port and culture
- Represents a key historical military/defense-oriented culture in the Southeast Asian region
- Is hosting the World Oceans Conference in May 2009
- Represents a distinct agro-ecological zone of inter-mountainous lacustrine plateaus and coastal zones significant for specific irrigated rice production in Southeast Asia
- Has international eco- tourism, agro tourism and historical/heritage tourism potential
- Straddles a geostrategic position between west and east Indonesia and between Southeast and Northeast Asia, with an historical link to the Philippines
- Has strategic significance as a “safe haven “ in case of regional destabilization, is of significance to the ASEAN community (and has been historically).
Key Environmental Assets and Development Issues in the North Sulawesi and Tondano Lake Watershed
North Sulawesi is fortunate as it has a number of assets and strategic location that provides a major potential for development. These include:
- Sulawesi and Maluku Seas – North Sulawesi province commands substantial part of the Sulawesi and Molluca Seas. These are highly significant regional seas that lie on major international shipping lanes connecting the Pacific and Indian Oceans, are rich in many fish species of high commercial value in particular in Tuna, Cakalang and Yellow Tail fish, and are a gateway to the BIMP –EAGA development area.
- Bunaken Marine National Park and other coral reef zones – Bunaken represents one of the World’s most diverse marine biodiversity zone, fish breeding and feeding zone and one of the global eco tourism assets. Fishing provide employment, local fish supply and also high value export source for the province.
- Dumoga Bone National Park- this national park represents major environmental asset in terms of forest and wildlife biodiversity with high significance for preservation of the biodiversity gene bank and research for Indonesia as wellas international community.
- Tondano Watershed- Tondano lake and river are major source of water resources for power generation, water supply, inland fisheries and has a major impact on the pollution and sedimentation control in the Manado bay, Bunaken and coastal water of Celebes Sea. The watershed is formed for most part from fertile soils ( Latosols and Allivial soils ), that produce high value agricultural and agro forestry crops and rice, there is abundance of renewable energy ( hydro energy, thermal and biomass derived), and it is rich in mineral resources and building materials, high eco and heritage tourism potential, and has relatively well educated population.
The consultants believe that the North Sulawesi has a major development potential comparable to Sarawak, the richest state in neighboring Federal Malaysia. However, like in Sarawak involvement of private investment, especially foreign direct investment is needed to kick off development, especially in present global economic climate.
Summary of Mapping of Critical and Flood Zones in the Tondano Watershed
According to the 2005 mapping there were identified large areas of critical lands in the Tondano lake watershed as well as flood zone area subjected to frequent regular (annual Q1) flooding.
The Tondano watershed has area was measured by the project at 57, 850 ha according to the 2003/5 study by Mott MacDonald Praha, see Map 1. The study indicated that there were 17 503 ha critical lands identified according to the methodology used in 2005 and 2010, that is 30,26 % of total area.
This was indication of very critical conditions that contributed towards pollution, sedimantation and decrease of depth, and degradation of water quality in the Tondano Lak.This alsocontributed to pollution of the coastal waters of Manado bay and degradation of the Bunaken Marine National Park.
Most critical part of the Tondano river watershed was identified as the sub-watershed „South“ or Tondano Lakte Watershed with an area of 28, 210 ha critical lands forming 33,76 % of this sub watershed or 9, 692 ha.The average depth of the Tondano lake was 15m. Sub watershed North -29 640 ha included 26,35 % critical lands and this constitutes 7 810 ha.
In 2010 the area of critical lands in the lake Tondano watershed ( sub watershed Tondano South ) identified on satellite imagery and field checked was 3, 281 ha or 11.6 % of the total area of the watershed and the average depth of the lake was 12m.
It is obvious that the presence of critical lands has contributed to the sedimentation and decrease of the lake’s depth over the years with introduction of intensive agriculture on steep slopes, logging and creation of areas with low vegetation cover. According to the JICA study ( 2000 ) using the USLE equation there is annually deposited between 6, 400 up to 7, 378 t of sediment annually in the Lake. It is obvious that rehabilitation measures, soil conservation are key in protecting the lake and coastal waters environments.
Summary of Assessment of Water and Sediment Samples from the Tondano Lake and Major Tributaries- Present Lake Water Quality Assessment
The sampling programe by the MottMacDonald Praha and Dekonta (associated Czech company ) was designed to assess contamination of the lake and tributaries by heavy metals and substances that effect the eutrification of the Tondano lake. In total 27 samples were taken from the lake and the tributaries. 23 were water samples and 17 were sediment samples. Special attention was placed on assessment of possible contamination by the Mercury.
The typical content of total Nitrogen seems at levels acceptabe by major international standards. Content of total phosporus in water samples from the lake Tondano tributaries are within tenths of mg per l.
The key sources of pollution of water from land sources are :
■ agro chemicals both organic and non organic fertilisers
■ waste water and sewerage from human settlements
■ run off, sedimentation and contamination by the key lake tributaries passing through intensive agriculture ( dryland and irrigated rice)
The key sources of pollution from water sources are:
■ cage fisheries in the lake that causes serious eutrification that countribute towards fast growth of water hyacint in the lake
■ contamination of the lake waters causes eutrification and reduction of oxygen levels
■ quality of water is below acceptable standars of Indonesian and international standards
■ highly significant is high concentration of Arsenic in about one fifth of the samples ( Arsenic is considered to have carcinogenous properties, however, it’s origin may be from geologic materials of the underlying rocks )
■ there is also high concentration of Zinc and Vanadium and this suggest a possibility of anthropogen origin ( concentration are not dangerous to human health )
■ no high levels of Mercury have been found in any samples
Seriousness of the environmental conditions in the Tondano lake watershed prompted the consultants to recommending a follow up study to the Czech Government so a series of rehabilitation demonstration plots would be set up to demonstrate rehabilitation techniques and act as the local Accelerated Rehabilitation and Development Centers ( ARDC ) in the Tondano watershed. The rehabilitation activities are By establishing better vegetative cover and use of soil conservation technologies, use of organic fertilizers ( compost ) it is expected to reduce sedimentation and pollution by agro chemicals in the Tondano lake and river.Subsequently this should also contribute to decrease of pollution from land sources in the Manado bay and coastal waters of North Sulawesi.