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TNB De-silting of DAM - What's all the fuss about? - 2005/05/05 09:21
NST 2/5/05
"INSTEAD of attacking the Pahang Government over its agreement to allow 80 hectares of land at Lubuk Tamang, Ringlet, Cameron Highlands, to be the dumping site for silt dredged from Tasek Ringlet, one should in fact praise it for the move.
Morever, it is not the whole area that falls under the Ringlet Forest Reserve, as claimed by Regional Environmental Awareness Cameron Highlands (REACH). The area that involves the forest reserves only covers 38ha of the total area approved. The State Government took the decision at its executive council meeting on Dec 5, 2001, following a request by Tenaga Nasional Bhd which needed the area to dump about four million cubic metres of silt to be dredged from Tasek Ringlet or the Sultan Abu Bakar Dam over 30 months. TNB will spend up to RM150 million on the exercise. This has never been done since the lake, or specifically the dam, was commissioned in 1968. With the approval, how- ever, not even all the 38ha of the forest reserve will be used for the dumping. The activities will be subject to strict procedures set by the Department of Environment (DOE). In fact, a detailed Enviromental Impact Assessment (EIA) was approved last June by the DOE. So what is all the fuss about? "
REACH's comment as extracted from website www.reach.org.my
Read these information below which have been extracted from the DEIA report and and decide for yourself what all the fuss is about.
Appendices
DEIA for the Proposed Rehabilitation of the Ringlet Reservoir, Cameron Highlands.
Methyl Mercury In Fish
Bacterial decomposition of benthic organic matter in made lake is known to cause the formation of extremely harmful mutagen and neurotoxin Methyl-Mercury (hereafter: Met-Hg). A recent review of the large scale impacts of dam construction indeed identified this problem-complex as one of the most important environmental impacts of dam construction (Rosenberg et al., 1997). Once Met-Hg is formed in the ecosystem, it may enter the food-chain via assimilation by multiple organism groups (Mason et al., 2000). Furthermore because it decomposes and is excreted slowly once it has been ingested by living organisms, it bio-accumulated to high concentrations at the top of the food chain (Castro et al., 2002). In addition, dredging activities are specifically known to re-suspend and mobilize Met-Hg that has been immobile in lake sediments. In a recent Finnish study, dredging activities were abandoned altogether due to the risk of Met-Hg contamination of the environment (Schultz et al., 1995). Met-Hg has dramatic health impacts such as neurological damages, and, above all, devastating effects on the developing human embryo if ingested by pregnant woman (Rosenberg et al., 1997).
Additional Information – DEIA for the Proposed Rehabilitation of Ringlet Reservoir, Cameron Highlands.
4.1.1.8 Potential Impacts on the flora
Tropical forest ecosystems such as that of the study site are extremely complex ecosystems with rich and varied life forms. These life forms have evolved over many years and have established linkages with one another and the surrounding environment. Many of these linkages have still not well been understood. Any interference to such an ecosystem will surely disrupt such an environment and the long term impacts and recovery is not accurately predictable. In highland environments there are always additional concerns because of the steeper terrain renders the area more inclined to soil erosions and slower recovery rates. It is thus very crucial to be able to be able to estimate the impact of intervention and ensure the impacts do not exceed the threshold level that will allow the overall natural system to recover from the intervention. However, it is not always clear what is the threshold level, consequently, a conservative and precautionary approach is always recommended to minimize the impacts of any project in forest ecosystems and often assistance through proper silvicultural treatments are adopted to enhance the recovery process. The forest of the study site has additional value as it is the last few remaining parcels of forest land within Ringlet that are still undisturbed.
4.1.1.8.2 Construction Phase
The project involves clearing of forest and permanent modification of the landscape. Consequently the project will definitely have many impacts on the flora and fauna of the forest ecosystem that needs to be carefully considered. At the same time some mitigation measures are suggested to protect the ecosystem. The clearing of a significant portion of the water catchments areas will result in an immediate loss of vegetation in the affected areas. The area consisting of undisturbed forest located in steep topography and a high elevation will be sensitive to intervention and the direct impact over time may also be considerable if proper care is not observed.
Amongst the expected potential impacts to the flora of study area can be summarized as follows:
Permanent loss of all vegetation in the landfill areas along the waterways of both catchments.
Soil erosion from the cleared sites and roads during construction and also part of post construction periods. Sediment load in streams may increase with adverse effects on stream stability, and bottom organisms (benthos) in the streams and the Ringlet Reservoir.
Logging may, indirectly make adjacent uncut forest more vulnerable to wind throw, fire and illegal felling. Adjacent or residual stands can suffer mechanical damage during logging.
Loss of carbon sequestration potential from the loss of forest area and release of green house gases from possible burning of woody debris from logging as well as land clearing and from decaying vegetation.
The forest within the study area is a diverse undisturbed montane forest that is very valuable simply because of the scarcity of such ecosystem within the country. Assuming that the affected area is about 54 acres, and then the total trees removed will amount to 6118 trees giving a total volume of about 4627 m3. In terms of total biomass removed, it is estimated that (using standard average figures for tropical forests, IPCC 2003) that for this study area an average of more than 360 tonnes/ha of biomass may be present in these forest. Subsequently, the total biomass loss for the affected areas amounts to about 7866 tonnes.
4.1.1.9 Mitigation Measures for Flora Conservation
Considering that the forest within the study area has high conservational value due its diversity of flora and the fact that it represents unique undisturbed water catchments within Cameron Highlands, it is extremely important that all necessary precaution be undertaken to minimize the impact of the project on the residual forest and enhance quick recovery.
4.1.1.9.2 Construction Phase
The implementation of the project will involve the use of some heavy machinery such as bulldozers, excavators, lorries and four wheel drives during construction phase. It would thus be necessary that effective precautionary measures be implemented to minimize earthworks and damage to the areas that are not expected to be affected.
A large part of the study area will still remain intact, thus significantly reducing overall long term impacts. The presence of these intact areas will also enhance the recovery of disturbed areas. However, the fillings of sediments in the affected areas are not easy to be revegetated because of the toxicity of the sediments and erodibility of the soil.
4.1.2.2.3 Results and Discussion
Apart from the Mountain Peacock Pheasant, there is another one species that need to be given full attention, which is the Waterfall Swift (Hydrochous gigas). Strange and Jeyarajasingam (1993) has not included this species in Peninsular Malaysia list, while Robson (2000) believed that this species is found in this country. One individual was captured from the study site and measurement and appearance of this individual fall within the range reported by Robson (2000). Although the captured individual was released, measurement and picture was taken for future study and identification. If this is indeed the waterfall swift, may be this is a new record for Peninsular Malaysia.
Feel free to call REACH for more information
www.reach.org.my
 
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