Hydro Power Potential in Sikkim- Impacts and Mitigations in Development of Hydro-Electric Projects in Sikkim.

Hydro Power Potential in Teesta basin

The river Teesta has great potential for development of power, as the river descends from an elevation of about 5,280 m to about 213 m over a distance of about 175 km. According to the preliminary reconnaissance survey by the team of experts of erstwhile Central Water & Power Commission in 1974, the river could be harnessed under cascade development for hydropower generation. The hydroelectric potential of the Teesta and its tributaries in Sikkim was estimated to be about 5505 MW Sikkim potential. The cascade development consists of power generation in sis stages along Teesta River. In addition Sikkim Power Development Corporation had identified more schemes to be development with the help of private agencies. Recently under the Hon’ble Prime Minister’s 50,000 MW, ten schemes were proposed for pre feasibility studies.

        Estimated Hydro-power Potential in Sikkim State

A = Schemes identified by Central Water Commission

B = Schemes being promoted by private agencies

C = Schemes identified under Hon’ble Prime Minister’s 50,000 MW initiative

General Impacts on Environment due to development of Hydro- Electric Projects

Generally multi-purpose Hydel power projects with large storage have impacts on larger scale. Even though on a smaller scale, run of the river projects would also impact the environment. The general impacts are listed below:

• Water Quality

 During construction of project water quality of river may be degraded due to disposal of untreated sewage from labour camps/ colonies, effluent from curshers and others sources.

• Ambient air quality:

During construction of project air quality of surrounding area may be affected due to fuel combustion in various construction equipment, Fugitive emissions from curshers, vehicular movement etc.

• Noise Quality:

During construction of project ecological environment including flora and fauna as well as aquatic ecology of the area may be degraded due to increased human interferences and project construction activities.

• Land Environment

During construction of project and environment of area may be affected due to quarrying operations, excavation of construction material from river bed, operation of construction equipment, soil erosion, muck disposal, construction of roads, pollution from construction sites etc.

• Ecological Environment

During construction of project ecological environment including flora and fauna as well as aquatic ecology of the area may be degraded due to increased human interferences and project construction activities.

• Socio-Economic Aspects

During construction of project socio economic environment of area may be affected due to impact on demographic and Socio-Economic environment, Immigration of labour population, public health and increased incidence of water-related diseases.

It should be emphasized that most of the above impacts are temporary in nature i.e. most of them are prevalent only during construction phases. Even these impacts can be mitigated by adopted suitable measures as apart of Environment Management Plan (EMP). Some of mitigate measures adopted in development of hydro-electric projects in Sikkim are outlines in the following paragraphs.

Measures adopted to mitigate the impacts as a part of EMP:

For each hydro electric project that is being up in Sikkim an exhaustive  Environment Impact Assessment Study has to be carried out and all the project specific impacts have to be assessed and suitable mitigants  have to be suggested and approved as a part of obtaining necessary environmental clearance and consents. Based on the environmental baseline conditions, planned project activities and impacts assessed, Environmental Management adverse impacts. The most reliable way to ensure the implementation of EMP is to integrated the management measures in the overall project planning, designing, construction and operation phases. EMP of a HEP includes the following measures to mitigate the negative impacts and enhance the positive impacts.

(1) Facilities in Labour camps

The spatial distribution of concentration of construction of construction activities ensures that labour population is likely to be concentrated at two or three major construction sites, i.e. dam, powerhouse and adit sites. It is suggested that contractor should make semi- permanent structures for their workers. These structures could be tin sheds. These shads can have internal compartments allotted to workers. The labour camp site shall have electricity and ventilation system, water supply and community latrines.

The water for meeting domestic requirements may be collected from the rivers or streams flowing upstream of the labour camps. The water can then be transferred to the labour camps, stored in tanks and utilized. The water quality in general is good and can be after chlorination.

(2) Solid waste management

The labour camps/ colony will be located at major construction site like dam site, powerhouse site and at adit sites. For solid waste collection, number of masonry storage vats should be constructed at appropriate locations in various labour camps. These vats should be emptied at regular intervals and the collected waste can then be transported to landfill site. Covered trucks to collect the solid waste from common collection point and transfer it to the disposal site should be put to service. A suitable landfill site should be identified and designed to contain waste from various Project Township, labour colonies, etc.

(3) Muck Management

For hydro-power projects, the quantity of muck generated is quite high fir setting up of various structures. Muck generated from excavation of any project component is required to be disposed in a planned manner so that it takes a least possible space and is not hazardous to the environment. In the hilly area, dumping is done after creating terraces thus usable terraces are developed. The overall idea is to enhance/ maintain aesthetic view in the surrounding area of the project in post– construction period and avoid contamination of any land or water resource due to muck disposal.

Suitable retaining walls shall be constructed to develop terraces so as to support the muck on vertical slope and for optimum space utilization. Loose muck would be compacted layer wise. The muck disposal area will to developed in a series of terraces of boulder crate wall and masonry will to protect the area/muck from flood water during monsoons. In between the terraces, catch water drain will be provided.

The terraces of the muck disposal area will be ultimately covered with fertile soil and suitable plants will be planted adopting suitable bio-technological measures. The basic aim and objects to the muck management plan are:

(i)                  To protect these areas from soil erosion

(ii)                To develop these areas by afforestration

(iii)               To develop them into parks, gardens etc.

(iv)              To utilize the maximum quality of musk for development of infrastructure.

(v)                To develop these areas in harmony with the landscape of the project area.

(4) Maintenance of water quality

During projects construction phase, sufficient measures should be implemented to ameliorate the pollution from various other sources. The sewerage generated from various labour camps is proposed to be treated in septic tanks and disposed into nallah/river. The septic tanks shall be located so as not to polluted the drinking water sources.

In the project operation phase, it is proposed to provide a sewage treatment plant for the effluent generated through Project colony, before disposal.

(5) Health delivery system

a)      Development of medical facilities

The labour population will be concentrated at major project component location sites. The dispensary should be developed at a site, which is accessible from the labour colonies. Doctors along with adequate Para-medical staff can be employed in dispensary and will reside in the staff quarters adjacent to the dispensary.

b) Proposed Health Facilities at Construction sites and labour camp

A first –aid post is to be provided at least the following facilities:

• First aid box with essential medicines including ORS packets
• First aid appliances- splints and addressing materials
• Stretcher, wheel chair, ambulance etc.

c) Provision of community kitchen

A community kitchen could be where workers have their meals. LPG or Kerosene can be used as fuel.

(6)  Restoration plan for quarry sites

During construction of a hydropower project large quantities of construction materials are required. The quarries would be stabilized after excavation of the construction material. Various biological and engineering measures would be adopted for the restoration of various quarry sites.

(7) Restoration and landscaping of construction sites

The construction of the project including its various appurtenances e.g. dam, powerhouse, approach roads, labour camps, project colony, etc. would slightly disturb the existing topography and physiography. Provision of landscaping of the area would be made, so that it integrates with the natural surrounding and the beauty of the area is restored according.

(8) Compensatory Afforestration

Compensatory afforestration should be done as per the norms of State Government, so that the loss of vegetal cover can be compensated by compensatory afforestration.

(9) Control of air pollution

The air pollution is basically generated due to primary crushing and fugitive dust from the heap of crushed material. Crushers need to be provided with cyclones to control the dust generated while primary crushing the stone aggregates. Provision of Cyclone/ Water sprinkler system should made mandatory to the contractor involved in crushing activities.

(10) Sustenance of Riverine fisheries

a) Maintenance of minimum flow for the migration of fish species provision of fish ladder should be made for sustenance of fisheries.

(11) Greenbelt development

The forest loss due to various project appurtenances should be compensated as a part of compensatory afforestation. However in addition to compensatory afforestation, it is proposed to develop greenbelt around the perimeter of various project appurtenances, selected stretches along the periphery of water spread area, road etc.

(12)  Forest Protection Plan

To minimize indirect impacts due to congregation of labour population, it is suggested to develop appropriate surveillance measures. It is suggested that check posts may be installed near major construction sites and labour camps. Each check post should have guards. A range officer should supervise the guards of various check posts. It is proposed that the staff manning these check posts have adequate communication equipment and other facilities. It is also proposed that wireless sets at each check post have been suggested. Apart from inter-linking of check posts, the communication wireless link needs to be extended to Divisional Forest Office and the local police station also. In addition to this provision of free fuel supply also made as a part of Forest Protection Plan. Project proponent in association with the State government will make necessary arrangements for distribution of kerosene oil and LPG. These fuels would be supplied at subsidized rates to the local / contract laborers for which the provision is normally kept in the cost estimate of EMP.

(13) Reservoir Rim Treatment plan

The main objectives behind the Reservoir Rim Treatment action plan is to check the sedimentation in the reservoir caused by the loose debris on critical slops, landslides and for stabilizing the foundations of the dwelling structures along the Reservoir Rim in due course of time.

(14) Disaster Management Plan

One of the preventive measures in avoiding dam failure disaster is by issuing flood warning of the imminent flood to the public residing in the areas likely to be affected, as early as possible if there is a possibility of dam failure.

(15) Catchment Area Treatment Plan (CAT PLAN)

It is a fact that all the reservoirs formed by dam on rivers are subject to sedimentation. The sedimentation carried by the river streams is mostly on account of erosion taking place in its catchment. Excessive sedimentation fills up the live storage capacity of the dam quickly, thereby reducing the active life of the project

It is suggested that the direct draining catchments area should be investigated more in details at the time of actual construction to identify the degraded areas. Following Engineering and Biological measures have been suggested for the Catchment area treatment.

Engineering measures

·        Step drain

·        Angle iron barbed wire fencing

·        Stone masonry

·        Check dams

Biological measures

·        Development of nurseries

·        Plantation/afforestration

·        Pasture development

·        Social forestry

The measures have to be implemented depending on the specific needs of the identified locations in the catchment area in consultation with the Forest Department of State Government.

(16) Rehabilitation and Resettlement Plan

Due to acquisition of land for different project components and related activities like construction of colony, approach roads, path, switchyard, etc. the families affected directly/ indirectly by the construction of the dam/ other ancillary structures will have to be adequately compensated for loss they will be suffering. Accordingly, an acceptable Local area development programme will have to be designed in line with the state and central policies in vogue in this regard. This should also involve a Local Area Development Programme which address to the needs of local people to improve their quality of life.

(17) Biodiversity & Wild life conservation

For the protection and conservation of Biodiversity & Wildlife, the management plan should be formulated in consultation with Forest and Wild Life Department.

(18) Environment Monitoring Programme

Monitoring is an essential component for sustainability of any water resources project. Monitoring of critical parameters is essential in the project construction and operation phase. Monitoring becomes essential to ensure that the mitigation measures planned for environmental protection function effectively during the entire period of project operation. The following parameter should be monitored on regular basis for the effective implementation of EMP:

• Water, air, noise, quality monitoring
• Erosion and siltation monitoring
• Meteorological aspects monitoring
• Ecological monitoring
• Fisheries monitoring
• Minimum release monitoring
• Incidence of water related diseases

Form the above, it is clear the even though the magnitude of impacts in setting up of the run of the river hydro-electric projects is small, there are exhaustive mitigation measures normally followed to ensure that the impacts are minimum and extra measures are taken for overall development if the ecology of the project area.

Benefits of Hydro Power Potential of Sikkim:

Benefits to the Nation, State and Locals

In addition to several advantages of HEP in general, the following benefits will be contributed to development of Nation, State and Local of area. The benefits can be summarized as:

• GDP Growth
• Revenues from Free Power and Environment Cess
• Clean Power- CDM perspective
• Minimum Diversion of land including Forest land
• Employment Generation
• Local Area Development

1.  Energy needs and GDP Growth

For each 1% growth in GDP, it is assessed that 5-6% growth is required in power generation. In the present and projected energy and peaking power shortages, addition of 5500 MW to the national grid would significantly contribute towards the national growth. Moreover the peaking nature of the power would benefit the national grid towards better Demand Supply Management and maintaining of grid stability.

Assuming an average completion cost of Rs. 5.5 cr. per MW, the state as well as nation would be destiny for a gross investment of Rs. 30,000 cr, which by any count is substantial contribution to state as well as national economy.

2. Revenues to the Government of Sikkim

As per the terms of development, GoS would get free of cost, 12% of power generated by the projects during the first 12 years of operation and 15% of power generated during 13-35 years of operation. After 35 yrs of operation, the project would be transferred to the State Government free of cost. This means the state becomes permanent owner for the entire generation.

In addition to free power revenues the state would levy environment cess @ 1paise/kwh. The details of free power and environment cess revenues are illustrated below:

It may be seen that the tariff rates assumed above are highly conservative, in view of the fact that these projects would materialize after 4-5 years are current tariff rates realized by State Government out of their free power from central pool are more than the Rs. 4/kwh. It is evident that the state would be bestowed with minimum revenue of Rs. 1600 crores per year in first 12 yrs and Rs. 3200 crores per year thereafter and Rs. 26,125 crores per annum after 35 years of operation.

3. GHG Emission Reductions:

Green House Gases (GHGs) are main cause of global warming which is leading to climate change in the Whole world. Now the entire world is seriously concerned in the reduction of GHG emissions. Hydropower generation will lead to negligible GHG emissions. These projects will contribute to the GHG emission reduction as they produce Green Energy. All the projects together will approximately generate

26152 million units of power per annum, which means they would be saving of 1, 88, 10,000 tones of carbon gas emission per year (@ 1 million unit = 720 tonnes of carbon dioxide). By any count this contribution is not small and would immensely benefiting the global environment. It may note that in the absence of development of project in Sikkim, the global would be warmer by such a huge amount of carbon emissions.

 The secondary benefit of clean power from Sikkim projects is that most of the projects qualify under Clean Development Mechanism (CDM) under Kyoto Protocol. This means the national economy would be benefited by revenues that accrue under CDM from developed countries.

4. Minimum Diversion of land including Forest Land

The total area of the state of Sikkim is 7096 sq km, i.e. 7, 09,600 Ha. The land requirement for run of the river projects is normally very small compared to the power as well as other benefits it accrues. The following table gives an approximate land requirement for various projects in the state of Sikkim

It may be seen that the total land required is only 2560 Ha out of the 7, 09,600 Ha of total area i.e. only 0.36 % of the total area. It is pertinent to mention that the land that is being permently lost is only 45% which means the permanent loss of land due to setting up of 5500 MW is only 0.162 % of total land. A typical analysis of land use for a run of the river project is illustrated below.

From the above, it is clear that of 2,560 Ha required to set up various hydro electric projects of Sikkim amounting to 5500 MW, only 2,280 Ha would be surface area. Out of such surface area, substantial land to the tune of 45% would be only of temporary use in nature for activities like Adits, contractor Facilities, Muck Damping etc. The permanent diversion for land 257 Ha is used for general infrastructure like roads and bridges. Only 769 Ha is used for general infrastructure like roads and bridges. Only 769 Ha is permanently diverted for the project components of 24 nos of projects of 5500 MW. This is only minuscule compared to the total area of the state of Sikkim. (i.e. 0.11%).

5. Employment opportunities to locals:

Setting up of various hydro electric projects in Sikkim would require man power to the tune of: 

§         Skilled Person                                      3000-5000

§         Semi skilled person                               6000-10000

§         Unskilled Person                                   6000-10000

As training programs would be part of LADP, most of the semi- skilled and unskilled persons could be hired from the local project area. This is a major benefit to the local people and creating such huge employment opportunities in the absence of development of the projects is a Herculean task for any State Government.

6. Local Area Development Programmers (LADP)

Each project involves comprehensives Local Area Development Programmed (LADP) which would benefit the local people in the process of projects development. The major features of LADP are outlined below.

(1) Training

The Training component will be in addition to the R&R facilities provided to the affected families. The basic purpose of the training is to involves the affected families into the project activities and improve the chance to having a better life style. One of the project proponents has already commissioned Teesta Industrial Training and Development Center and started upgrading the unskilled