Wainganga Report (Previous Project)

PFR STUDIES OF WAINGANGA H.E. PROJECT

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CHAPTER-I EXECUTIVE SUMMARY

1.1 INTRODUCTION

The Wainganga Hydroelectric Project located on the border of Gadchiroli and

Chandrapur districts of Maharashtra State envisages utilization of the water of

the river Wainganga, a tributary of Godavari for power generation on a

storage type development, harnessing a hydraulic head of about 25.4 m.

The project with a proposed installation of 105 MW (5 x 21 MW) would afford

an annual energy generation of 246.146 GWh in a 90% dependable year. The

tariff from the project at present day cost would be Rs. 3.32/ kWh (levellised).

The diversion site is located at Latitude 200 23’0” N, Longitude 790 57’ 35"E.

The nearest rail head to the project area is located at Bramhapuri about 25

km upstream of project site. Bramhapuri is connected to Nagpur (about 130

km) via Umred-Nagbhir section. The project is also approachable by road by

the same route i.e. Nagpur-Umred-Nagbhir-Brahmapuri. Another approach

can be from Chandrapur (District headquarter) located about 150 km from

Nagpur and connected by National Highway/State Highway. The Wainganga

dam site is located at a village Daungar Saungi which is about 95 km from

Chandrapur via Kelzar-Mul-Gadchiroli-Purla by state highway and further 10

km by single lane ordinary road going upstream along the Wainganga river.

The nearest airport is located at Nagpur.

1.2 SCOPE OF WORKS

The Wainganga HE project envisages construction of :


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• a 32 m high concrete power dam and overflow section and rest all is

earthen dam across river Wainganga to provide a live storage of

5155.0 M cum with FRL at El 222.4 m and MDDL at El 212.0 m

• 70.0 m long and 5.0 m dia penstock – 5 Nos.

• A surface power house having an installation of 5 Kaplan turbines

driven generating unit of 21 MW each operating under a gross head of

25.4 m; and

• 300 m long tail race channel to carry the power house releases back to

the river.

1.3 HYDROLOGY

The river Wainganga drains a total catchment area of 43658 sq km at the

project site which includes free catchment area of about 8796 sq km. The

water availability for the project i.e. the dependable flows both for 90% and

50% dependable year have been assessed, based on observed data and

incorporating 12 Gauge Discharge sites (maintained by CWC) in the region

utilising the available data from 1970-71 onwards for most of the sites. The

computed inflow series worked out has been utilized for Power Potential

Studies. The design flood (PMF) has been assessed as 63330 cumecs.

1.4 POWER POTENTIAL STUDIES

Annual energy generation has been computed for all the 31 years (1970-

2001) with installed capacity of 105 MW. The annual firm power generation is

computed as 153.3 million units. The average annual generation considering

secondary energy generation works out to 246.146 million units.


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1.5 POWER EVACUATION ASPECTS

The line from this HEP is intended to be evacuated by purposed 220 KV D/C

line to newly proposed 220/132 kV S/S near Chandrapur.

1.6 ENVIRONMENTAL ASPECTS

The project site is located in reserve forest area on river Wainganga. The

submergence area is 87500 ha, and about 80% of the land falls under the

category of forest area and clearances under Forest Conservation Act shall

be required. In addition, land will also be required for other project

appurtenances. Based on assessment of environmental impacts,

management plans have to be formulated for acquisition of forest land, wildlife

conservation, muck disposal, quarry stabilization, and other environmental

issues. These issues would be addressed during the investigation stage for

DPR preparation.

1.7 ESTIMATES OF THE COST The project is estimated to cost Rs. 1321.77 Crores including IDC at

June,2003 price level. The preliminary cost estimate of the project has been

prepared as per guidelines of CEA/CWC. The break up of the cost estimate

is given below:

Particulars Rs. (in Crores)

Civil Works : 936.91 Electro Mechanical Works : 178.70 Sub Total (Generation) : 1115.61 Interest During Construction : 176.41 Total (Generation) : 1292.02 Transmission Works : 29.75 Grand Total : 1321.77


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1.8 FINANCIAL ASPECTS As indicated above, the Wainganga HE Project, with an estimated cost

(Generation only) of Rs. 1292.02 Crores (including IDC of Rs. 176.41 Crores)

and design energy of 246.146 GWh in a 90% dependable year is proposed to

be completed in a period of 5 years. The tariff has been worked out

considering a debt-equity ratio of 70:30, 16% return on equity and annual

interest rate on loan at 10%. The tariff for first year and levellised tariff (at

power house bus bar) have been worked out as Rs.3.86 /kWh & Rs.

3.32/kWh respectively.

1.9 CONCLUSIONS

9.1 The Wainganga HE Project involves simple civil works and could be

completed in 5 years. The project would afford a design energy of 246.146

GWh in a 90% dependable year. The cost per MW installed work out to Rs.

10.62 Crores. The Preliminary Feasibility Report indicates that the scheme

merits consideration for taking up Survey & Investigation and preparation of

DPR, especially considering the scenario that releases from this storage

project are proposed to be utilised for generation of power on a run-of-the-

river type development in respect of 3 H.E. Schemes proposed in the

downstream reach.

9.2 Godavari Water Disputes Tribunal Report imposes restriction on utilisation of

1.5 TMC at every stage utilisation and that there is a limitation to use 41 TMC

by Maharashtra State. However, Wainganga Hydel Development does not

entail consumptive use of water except for evaporation and hence the above

restrictions do not infringe any of the provisions of the award.


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CHAPTER - II BACKGROUND INFORMATION

2.1 General

Maharashtra is the third largest State in area and second most populous

State. It is located in the Western part of the country with long coast line on

the Arabian Sea and the State includes major portion within the Central part of

the Peninsular India. It occupies 9.0% of the land area and supports 9.4% of

the population (Census 2001). It is bestowed with low hill ranges and is

traversed by major river systems. The surface water resources of the State

comprise of the river systems of Krishna, Bhima, Godavari, Tapi, Purna,

Wardha, Wainganga. It has rolling topography with hill ranges of Satpuda Hills

along the northern border, Bhamragad-Chiroli-Gaikhuri ranges on the east

serving as natural limits to the State. The Sahayadri Range rises to about El

1000 m and fall in steep cliffs to the Konkan on the west. The Konkan area

between Arabian Sea and the Sahyadri Range is narrow coastal land about

50 km wide and is highly dissected and broken between narrow, steep valleys

and laterite plateaux.

The State has tropical monsoon-climate with seasonal heavy rains of about

400 cm from the west in the Sahyadri. It has also heavy rain on the windward

side on the Konkan and declines towards north-east of Sahyadri. The rainfall

decreases to 70 cm in Sholapur and Ahmednagar. The state supports 17% of

the forest area. The Maharashtra is one of the most advanced states of India

as regards industry, trade, transport and communication.

Maharashtra has very rich heritage of ancient monuments. It has the finest

examples of Indian architecture carved out of natural rocks in distinctive styles


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at several places scattered all over the state. Mumbai, the state capital, is

called the commercial capital of India. It is also known as the ‘Gate of India’

and serves as the major port of western India.

Maharashtras’ contribution to the Indian economy is high and it is called as

the power house of India. Maharashtra with 9.4% of the population accounts

for nearly one-fourth of the gross value of India’s industrial sector. The state

has achieved high levels of industrialization. This is evidenced by the fact that

secondary and tertiary (manufacturing and service) sectors contribute 78.8%

of Maharashtra’s Gross Domestic Product, as compared to the national

average of 65.4% for the same fields. The per capita income of the State is

about Rs. 17,295/- against national average of Rs. 10,771/-. It contributes

14.7% to the GDP and 15.1% to the national income.

2.2 POWER SCENARIO IN WESTERN REGION 2.2.1 Present Status

The Western Region comprises of the states of Maharashtra, Madhya

Pradesh, Gujarat, Goa, Daman Diu and Dadra & Nagar Haveli. Most of the

states are suffering from lower growth rate in energy as against the expected

projections. Also that most of the states suffer due to severe peak load

shortages. The percentage pattern of actual utilization of electrical energy

during 1997-98 are given below in Table 2.1 (Ref: Sixteenth Electric Power

Survey of India, CEA):


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Table 2.1 Percentage Utilization Sector wise

Categories Actual (1997-98)

Projected (2003-04)

Domestic 24.28 26.48

Commercial 9.39 9.24

Irrigation 30.90 26.99

Industry 28.66 30.76

Others 6.77 6.53

Total 100.00 100.00

The statewise energy requirement at power station Bus-bars and energy

consumption as per estimate of 2002-03 are given as under in Table 2.2

depicting overall energy deficit of 18.5% in the Western Region.

Table 2.2 Energy Status (M Kwh)

State Requirement (M Kwh)

Estimated consumption

Shortage/ Surplus

% variation

Goa 1826.0 1341.76 -484.24 -26.52

Gujarat 49141.0 39075.98 -10065.02 -20.48

Madhya Pradesh 41517.0 33255.48 -8261.52 -19.70

Maharashtra 84504.0 70460.48 -14043.52 -16.62

Dadra & Nagar

Haveli

988.0 880.58 -107.42 -10.87

Daman & Diu 639.0 584.43 -54.57 -8.54

Western Region

(Total)

178615 145598.71 -33016.29 -18.49


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2.3 NECESSITY OF HYDRO POWER DEVELOPMENT IN THE STATE 2.3.1 Scenario of Hydro-electric Projects

The scenario of hydro-electric projects completed so far in Maharashtra State

is given in the Table 2.3 and the projects under construction given in Table

2.4:

Table 2.3 Completed Projects

Sr No

Name of Hydro-Electric Project

Number of Generator units installed

Capacity of each unit (MW)

Total potential (MW)

Konkan Region

1 Koyana Stage III 4 80 320.00

Bhira 2 40 80.00

3 Bhatsa 1 15 15.00

4 Terwanmedhe 1 0.20 0.20

5 Surya 1 6 6.00

6 Surya RBC fall 1 0.75 0.75

Pune Region

7 Radhanagari 4 1.20 4.80

8 Koyana stage I 4 70 280.00

9 Koyana stage II 4 80 320.00

10 Bhatghar 1 16 16.00

11 Vir 2 4.5 9.00

12 Tillari 1 60 60.00

13 Pawana 1 10 10.00

14 Yevteshwar 1 0.075 0.075


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15 Khadakwasala 2 8 16

16 Kanher 1 4 4.00

17 Dhom 2 1 2.00

18 Ujani 1 12 12.00

19 Manikdoh 1 6 6.00

20 Dimbhe 1 5 5.00

21 Warna 2 8 16.00

22 Dudhganga 2 12 24.00

23 Koyana Stage IV 4 250 1000.00

Nashik Region

24 Vaitarna (Underground) 1 60 60.00

25 Vaitarna (Dam toe) 1 1.50 1.50

26 Bhandardara PH- II 1 34.0 34.00

27 Karanjwan 1 3.0 3.00

Marathwada Region

28 Yeldari 3 7.5 22.5

29 Paithan 1 12 12.0

30 Majalgaon 1 0.75 0.75

Nagpur Region

31 Pench (Interstate project) 2 80 53 (33%)

Projects completed by M/s TATA

32 Bhira 6 25 150.00

33 Khopoli 6 12 72.00

34 Bhivpuri 6 12 72.00

35 Bhira 1 150 150.00


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Projects completed by Private Agencies

36 Bhandardara PH-I 1 12 12.00

37 Vajra Prapat 1 3 3.00

Total Potential Created 2852.575

Table 2.4 Projects Under Construction

Sr No

Name of Hydro-Electric Project

No. of Generator units Proposed

Design Capacity of each unit (MW)

Total potential (MW)

Konkan Region

1 Ghatghar 2 125 250.0

Pune Region

2 Dolvahal 2 1 2.00

3 Konal 2 5 10.00

4 Chass Kaman 1 3 3.00

Nashik Region

5 Sardar Sarovar

(Interstate)- 27% 391.50

Marathwada Region

6 Majalgaon 3 0.75 2.25

7 Shahanur 1 0.75 0.75

Total Estimated potential of ongoing projects 659.50


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2.3.2 Hydro and Thermal Power Mix

The main sources for generating electricity in Maharashtra are Hydro,

thermal, nuclear and wind energy. The position of electricity generation by the

end of 9th five year plan (2001) is given in Table 2.5.

Table 2.5 Fig. In Mw

Thermal Sector Hydro

Coal Gas Diesel Total

Nuclear Wind Total

State 2400.17 6425 912 0 7337 0 6.4 9743.57

Private 447 1650 920 0 2570 0 313.8 3330.80

Central 0 1339 391.9 0 1730.9 297 0 2027.90

Total 2847.17 9414.0 2223.9 0 11637.9 297 320.2 15102.27

The development of Hydro-electric and thermal energy generation in

Maharashtra is quite disproportionate and the percent share of hydro is 20%.

With the diminishing coal reserves and difficult oil position all over the world, it

is necessary that economic balance of 40:60 between hydro and thermal

generation of power is obtained.


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2.3.3 Actual Power Supply Position

The actual power supply position in the State is given in Table 2.6.

Table 2.6 Actual Power Supply Position

Period Peak Demand (MW)

Peak Met (MW)

Peak Deficit(-)/ Surplus (+) (MW)

Peak Deficit(-)/ Surplus (+) (%)

Energy Require-ment (MU)

Energy Availa-bility (MU)

Energy Deficit(-)/ Surplus (+) (MW)

Energy Deficit(-)/ Surplus (+) (%)

2001-02 (Terminal year 9th plan)

12265 10726 -1539 - 12.5 80489 73438 -7051 -8.8

2002-03 13697 10984 -2713 - 19.8 87152 75472 -11680 -13.4

April-Oct 2003

13612 11078 -2534 - 18.6 48845 44559 -4286 -8.8

2.3.4 Capacity addition during 10th Plan (2002-2007)

The capacity addition of energy from major sources during the 10th Five year

plan period as assessed by Planning Commission is given as under in Table

2.7.


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Table 2.7 Capacity addition during 10th plan

Name of project (Central Sector)

Type IC (MW) Capacity addition during 10th plan MW

Benefit / Shares MW

TARAPUR U-3&4 N 1080 1080 471

SIPAT STPP ST-I T 1980 1320 444

VINDHYACHAL III T 1000 500 168

BAV-II H 37 37 16

Total 4097 1099

State Sector

GHATGHAR H 250 250 250

SARDAR SAROVAR-2 (27%)

H 1450 1450 391.5

PARLI TPP ST-I T 250 250 250

Total 1950 2655 891.5

Private Sector

DABHOL II LNG 1444 1444 1444

Total 1444 1444 1444

Grand Total 3434.5

2.3.5 The anticipated power supply position at the end of 10th plan period i.e. 2006

shall be as under in Table 2.8.

Table 2.8 Anticipated power supply position

Peak Demand (MW)

Peak Availability (MW)

Peak Deficit(-)/ Surplus (+) (MW)

Peak Deficit(-)/ Surplus (+) (%)

Energy Requirement (MU)

Energy Availability (MU)

Energy Deficit(-)/ Surplus (+) (MW)

Energy Deficit(-)/ Surplus (+) (%)

16716 13271 -3445 -20.6 106892 85465 -21427 -20.0


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2.4 BRIDGING THE GAP OF HYDRO POWER GENERATION

With a view to prioritize the large number of identified H.E. schemes to

harness the vast untapped hydro resources in the country ranking studies

have been carried out by Central Electricity Authority, Ministry of Power, Govt.

of India to take up H.E. projects in the order of their attractiveness for

implementation. Subsequently, after consultation process initiated by Ministry

of Power with various state agencies, CPSUs etc., it was considered

appropriate that Preliminary Feasibility Report (PFRs) of selected hydro-

electric projects in Maharashtra State be taken up so that feasibility of the

schemes considered in ranking studies could be established.

The list of H.E. projects proposed for PFR studies in Maharashtra State is

given as under in Table 2.9.

Table 2.9 List of the Projects for Preparation of PFRs in Maharashtra State

1. Wainganga H.E. Project Godavari River Basin

2. Samda H.E. Project Godavari River Basin

3. Ghargaon H.E. Project Godavari River Basin

4. Kunghara H.E. Project Godavari River Basin

5. Pranhita H.E. Project Pranhita River Basin

6. Kadvi H.E. Project Varna River Basin

7. Kumbhi-I H.E. Project Krishna River Basin

8. Kasari-I H.E. Project Kasari River Basin

9. Hiranyakashi Vedganga H.E. Project Vedganga River Basin


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In order to improve upon the share of hydro-power generation it is essential to

develop the hydro-power potential of the State to give further accelerated

growth to the Industrial expansion in the State and accordingly this report

presents the prefeasibility stage studies of the Wainganga H.E. Project, located on the boundary of Gadchiroli and Chandrapur Districts of

Maharashtra State and is detailed in the following chapters.


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CHAPTER - III THE PROJECT AREA

3.1 GENERAL

The Wainganga H.E. Project is located on the Waingaga river which is one of

the major tributaries of Godavari river. The Wainganga river rises at

El 640.0 m in the Seoni District of Madhya Pradesh from the Western slopes

of Maikala Ranges which is continuation of the Satpura Ranges in Central

India. The river in its the initial reaches flow westwards and thereafter

southwards in M.P. State and continues to flow Southwards in Maharashtra

State. It is joined by the Wardha river at a place called Gundapet flowing from

the west, draining the major portion of the Maharashtra Plateau. Thereafter

the river is known as Pranhita river. The upper catchment area lies in the high

rainfall range of 2000-4000 mm. The Prahnita river joins the Godavari river on

the left bank which drains the Eastern Coast in Andhra Pradesh and flows out

to the Bay of Bengal. The Wainganga H.E. Project is the second major project

proposed on river Wainganga in the Maharashtra State, the first being

Gosikhurd Project (under construction) in the upper reaches of Wainganga.

The Wainganga H.E. project is proposed as a storage project followed by the

Run-of-the River schemes downstream to utilise the regulated discharges for

generation of power at the Samda, Ghargaon and Kunghara H.E. projects in a

cascade development for exploiting the hydropotential of the Waingaga river.

The Wainganga H.E. project is a Dam-toe power station and utilises the live

storage of 5155 M cum proposed to be created by a gravity dam with crest

gates in the main river reach flanked by earthen dam on both the flanks. The

Gravity Dam is located at river bed level of El 196.0 m near a village called

Daungar Saungi downstream of the confluence of the Khobragarhi Nadi

flowing from the east and joining on left bank. The Wainganga forms the


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border of Chandrapur and Gadchiroli districts flowing north-south in

Maharashtra State and the dam is located on the border of the two districts at

Latitude 20o 23’ 0” N and Longitude 79o 57’ 35” E.

3.2 CLIMATE

The sub-basin has a dense network of six meteorological stations located at

Chhindwara, Seoni, Gonda, Nagpur, Chandrapur and Brahmapuri. The

climate of the sub-basin is characterized by hot summer from March to May

with rainy season from June to September although the area has some rains

in post monsoon season also. The summer is slightly milder in the part sub-

basin in M.P. State than that lying in Maharashtra and Andhra Pradesh

States. Mean daily maximum temperature varies from 26o-30o C in July to

32o-33o C in October and show a general increase from north to south and

from coast to up country in the west. The minimum daily temperatures varies

monthwise viz. 10o to 15o C in January, 22o to 26o C in August, 23o to 25o C in

July and 18o to 22o C in October. The wind velocity ranges from 3 to 7 km per

hour during Oct. to May and 8 to 10 km per hour from June to September

caused by South West monsoon.

The isohyte of 1500 mm passes the river parallely where the Dam-toe power

station is proposed.

3.3 SOCIO-ECONOMIC PROFILE

The State is divided into 31 administrative districts spread over in 325 Tehsils

covering 41251 villages (excluding 2613 un-inhabitated villages) and 336

urban centres. About 70% of the population depend on agriculture. It has

21.662 M ha as gross cropped area with only 15.4% area as irrigated. The


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Irrigation projects are generally multi-purpose having irrigation and hydro-

power components.

The State is the second most populous State in India with female ratio of 922

per 1000 males and population density has reached 314 per sq km (Census

2001). The literacy rates of 67.5% and 86.3% respectively have been

achieved among the female and male population. The same in Chandrapur

and Gadchiroli Districts is only at 2/3rd of the State averages. Urban

population constitue about 41%. The area under operation holding for

agriculture in the State has marginally declined but has shown relatively

higher cereal production.

The eastern districts covering Chandrapur, Gadchiroli and Bhandara have a

low population density of 116 persons per sq. km as against the State

average of 336 and constitute highest Schedule caste and Schedule tribe

population of 29.83% (1990-91 fig.). It has lateritic soils and grow mostly

coarse cereals The land holdings are small and the districts support large

forest boundary. However, the literacy rate in Chandrapur and Gadchiroli are

in the range of 30-45% and 45-60% respectively which are much lower than

the State averages.

The percentage of urban population in Gadchiroli is least (in the range of upto

10%) and Chandrapur has 25 to 50% urban population as compared to + 50%

for Pune area . The house hold size in the Chandrapur area, Gadchiroli

Districts are 4.57 and 4.83 as against 5.14 for whole of Maharashtra State.


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CHAPTER – IV

TOPOGRAPHY AND GEOTECHNICAL ASPECTS 4.1 GENERAL

The Wainganga H.E. Project is located on the Waingaga river which is one of

the major tributaries of Godavari river. The Wainganga river rises at

El 640.0 m in the Seoni District of Madhya Pradesh from the Western slopes

of Maikala Ranges which is continuation of the Satpura Ranges in Central

India. The river in its initial reaches flow westwards and thereafter southwards

in M.P. State and continues to flow Southwards in Maharashtra State. It is

joined by the Wardha river at a place called Gundapet flowing from the west,

draining the major portion of the Maharashtra Plateau. Thereafter the river is

known as Pranhita river.

The project is located on the border of Gadchiroli and Chandrapur districts of

Maharashtra State envisages utilization of the water of the river Wainganga, a

tributary of Godavari for power generation on a storage type development,

harnessing a hydraulic head of about 25.4 m for generation of power with

installed capacity of 105 MW (5x21 MW).

The Wainganga in the project area has a very flat gradient of the order of 1 in

2500 and runs in a wide valley with width varying from 700 m to 1100 m. The

area is characterized by frequent rock exposures in the bed of the river and

along the flanks.


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4.2 REGIONAL GEOLOGY

The essential geological unit covering most of the area comprises of granite

and granite gneisses which have been cut by later dykes comprising of

dolerite and other basic intrusives. Interstratified with hornblende-schists

amphibolite bodies are well exposed in the Wainganga river section. Apart

from these a series of quartzite and schist comprising of Archean

metasedimentaries are also well exposed in the northeastern part of the area.

The mutual contact relationship of the different rock units are not very clearly

identifiable owing to thick forest and soil cover. Based on field observations

the stratigraphic succession of the area worked out is given below:

Recent to Quartz vein/pegmatites

sub-Recent

Amphibolites

Amgaon Quartzites

Archaean Gneissic Banded Iron Formation

Complex Gneisses/migmatites

The general distribution of the different rock types and lithological variation is

well reflected in the topography of the area. Gneisses occupy the major area

and is the most prominent rock type which forms an undulatory topographic

expression of the area. The resistant rock types such as amphibolites,

quartzites and Banded Iron Formation outcrop as prominent narrow ridges.

The younger granites and basic dykes and other intrusives on the other hand

have given rise to small domical hills in the area. Patches of low lying area

particularly in the western half have also developed from laterite capping over

the gneisses.


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Gneisses/migmaties

Though these are the most abundant rock types in the area, they do not form

any conspicuous topographic feature due to their pronounced weathering. As

a result, outcrops are rare and are noticed only in the nala and river sections.

The rocks

show marked variation from a coarse grained-gneiss to fine-grained rock

within a short distance and become micaceous. These are often intruded by

pegmatite and quartz veins both across and along the plane of foliation.

In thin sections, the rock consists of quartz, felspar, biotite and the other

accessory minerals. The quartz shows undulatory extinction and at places is

granulated. The felspars are generally turbid due to alteration and both albite

and varying proportion of potash felspar are present. Biotite is the main dark

constituent, while minor amount of muscovite is also noticed. Apatite, epidote

and sphene occur in minor amounts. In some thin sections small ragged

crystals of hornblende are also noticed, which may perhaps be relict.

Banded Iron Formation

They are conspicuously exposed near Mohjhari, Purla, Armori in Kandesar

Pahar and in Khobragarhi river section. The outcrops near Mohjhari exhibit

well developed local anticlinal and synclinal folds with their fold axes trending

NNW-SSE to NE-SE, plunging 50 to 70 degrees towards NW. Finely banded

character and close folding are observed almost every where in these rocks.

The rocks are brownish grey in colour, fine grained, hard and compact and

consist of alternate layers of either magnetite or hematite and quartz. They

vary considerably in width, from a few millimeters to a few centimeters. These

layers are of different colours, from black through dark brownish red and light

red to brown. The quartz in some bands is cherty, in others it is relatively


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coarse-grained. The bands display well developed joints and dislocate layers

at places. Minute veinlets of quartz and iron ore commonly cross the bedding.

The laminae at places pinch out sharply.

Quartzites

Quartzites constitute the prominent ridges near Dewalgaon, Dongarasaungi ,

Thanegaon, Akapur, Selda and Saigaon. They are white, buff, light brown

and bluish grey in colour. The brown shades in the rocks are attributable to

the decomposition of iron bearing minerals dispersed by surface water and

coating the grains and forming films in the cracks and crevices. These rocks

are, at places, micaceous, while some consist almost entirely of sheared

quartz. In texture they range from fine to coarse grained.

In thin sections, they are mainly composed of sheared quartz with small

quantity of muscovite, biotite and ore. The bluish quartzites from the hill SE

of Saigaon, contain mica and dusty inclusions of ore.

Amphibolites

They are interstratified with hornblende-schists in Wainganga river section,

south of Mendki and in most of the nala sections in the area. These

amphibolite layers appear to be lensoid inclusions enclosed in the granite-

gneiss. The rocks are dark, and generally have a mottled appearance due to

the presence of felspar, quartz and light coloured epidote. Thin veins of

quartz and pegmatite, showing minute folds are noticed in some of the

exposures.

In this sections they appear to be composed of a highly pleochroic, green,

acicular hornblende, showing a preferred orientation. Quartz and plagioclase


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felspar occur in variable amounts, while minor amounts of garnet and ores are

also observed.

At places pegmatitic material has been injected into the hornblende-schists

and aphibolites along their planes of foliation, imparting a banded appearance

to these rocks. They show profused development of pink garnet ranging in

size from 0.2 to 1 centimetre across at Potesar-Ghat in Wainganga river.

Quartz Veins / Pegmatites

They are commonly noted intruding the gneisses all over the area. Good

exposures are however, noticed in Wainganga river near Katli, Halda, at the

confluence of Kholandi nala and the Wainganga river, and in the nala north of

Ekara. They consist essentially of coarse masses of quartz and felspar, the

latter being pink microcline. Tourmaline and mica are occasionally

developed. Thin epidote veins are noticed in some of the hand specimens.

4.3 STRUCTURE AND TECTONICS

Foliation: The General trend of foliation in the Archaean suite of rocks veers

between NNW-SSE and WNW-ESE with steep dips either towards SW, SSW

or NE. At places, the trend of rocks changes to NNE-SSE with WNW dips

varying between 30 and 70 degrees.

Lineation: Linear arrangement of minerals in amphibolites show plunges of

20o to 30o from NW to West, while in gneisses, the lineation is parallel to the

plane of foliation.

Joints: Four sets of common joints displayed by Archaean suite of rocks are

(1) N800W-S80oE with vertical dip


4-6

(2) N45oE -S45oW “ “ “

(3) N30oW-S30oE “ “ “

(4) N10oW-So10oE with dip 25o towards N80oE.

Folds: The variation in strike and dip directions as indicated above, suggestS

a series of anticlinal and synclinal folds with their axes plunging between 30

and 50 degrees towards north-west. Such abrupt changes in strike and dip

directions are recorded in the nala sections near Padmapur, Mendki,

Gunjewahi and at the confluence of Wainganga-Khobragarhi rivers. Banded

magnetite-quartzites near the village Mohjhari, exhibit well developed local

anticlinal and synclinal folds with their axes plunging between 50 and 75

degrees towards WNW. Miniature folds are very common in hard compact

gneisses, amphibolites, quartzites and banded magnetite-quartzites, with

pegmatite and quartz veins traversing the hornblende-schists and

amphibolites and display fine ptygmatic folds. These are seen in the

Wainganga river section near Potesar. Puckering is observed in the quartz-

schists, on the hill west of Dewalgaon. Shearing and crushing is very

conspicuous in the quartzites, resulting in their brecciated appearance. Thin

quartz veins ramifying in all directions are conspicuous in the brecciated

quartzites.

Faults : The brecciated quartzites, which are clearly the result of crushing and

shearing phenomena, form the narrow ridges tranding NNW to NW near

SeosagarTaluk, Rampur Jankapur and Akapur, and perhaps suggest a series

of fault zones.

4.4 SEISMOTECTONICS AND SEISMICITY

The project is located in the region forming Telangana region of Andhra

Pradesh and a small southeastern part of Maharashtra. The entire region


4-7

barring the southwestern part constitutes a segment of Godavari River Basin

with major tributaries such as Pranhita and Indravati, flowing south. The tract

between Warangal and Hyderabad forms the drainage 'divide between the

Godavari Basin in the northeast and Krishna River Basin in the south-western

part.

The area comprises two major tectonic domains viz. the eastern Dharwar

Craton and the southern most part of the Bastar Craton separated by the NW

trending Godavari Rift Basin. The Dharwar Craton in this part of the terrain is

represented by basement elements comprising gneisses and migmatites of

Peninsular Gneissic Complex (with vestiges of TTG and earliest

supracrustals) and the granulites, of Khammam Belt. The basement gneisses

are overlain by Meso-Proterozoic platform covers of Pakhal comprising the

shelf facies rocks, exposed all along the shoulder of Godavari Rift system. In

the northern part of this craton the basement as well as the cover rocks of

northwestern extremity of the Godavari Graben have been overplated by the

continental flood basalts of Late Mesozoic - early Cenozoic period.

Tectonically, the Bastar Cratonic domain in the sheet area presents a

heterogeneous picture in the sense that the terrain exposes the earliest

basement as well as the most recent alluvial covers. The basement of this

craton is represented by granite gneisses, with enclaves of earliest

supracrustals (Bengpal Group), the charnockites and khondalites of

Bhopalpatnam Granulite belt ; the folded bimodal volcanic suite of Nandgaon

Group and the homophanous granitoids of Dongargarh . The basement is

overlain by moderately deformed volcano-sedimentary covers in abortive rift

basins, represented by Abujmer Group of rocks. The other sedimentary

platform covers are undeformed shelf sediments, ranging in age from Late

Proterozoic to Early Palaeozoic occurring in small interior basins in the area.


4-8

The Godavari Graben, separating the Eastern Dharwar and Southern Bastar

Cratons represents a polycyclic rift system, probably initiating in the Middle

Proterozoic as evidenced by the Pakhal and Sullavai shelf sediments

preserved in the basin periphery deposited during the early aborted rift cycle.

The major part of this rift basin, at present, is represented essentially by

terrestrial facies cover, (Gondwana rocks) with occasional marine

transgressive sediments. The Godavari Basin can be subdivided into two sub-

basins separated by the Mailaram high. The disposition of the Godavari

Graben is parallel to the tectonic grain of both Bastar and Dharwar Cratons,

and in the vicinity of both the eastern and western shoulders of the basin, it is

marked by northwest trending thin granulite belts. The basin however cuts

across the NE trending Eastern Ghat Granulite Belt.

The principal structural trend in the basement complex and ancient

supracrustal belts in both Dharwar and Bastar Craton is NNW-SSE to N-S.

The platform cover rocks occurring in the interior sag basins do not show

much deformation. The terrain is traversed by fairly dense network of NE and

NW and a few E- W trending lineaments. In the central part of the area the

Godavari Basin is bound by parallel en-echelon fault system, some of which

have affected both the basement and cover. Three major faults in the area

indicate neotectonic signature. They are WNW -ESE trending Kadam Fault,

the Kinnerasani -Godavari Fault with its splays and the Godavari Valley Fault.

The eastern margin of the Godavari Graben is bound by NNW -SSE trending

basin margin fault. The basin architecture is further controlled by a series of

horst and graben structure formed by longitudinal as well as transverse faults.

The western margin of the basin is however, not controlled by a continuous

boundary fault.


4-9

Seismicity of the terrain is mostly confined to the Godavari Basin, particularly

towards its southeastern end in the Bhadrachalam area. A total of 29 events

have been recorded from this region upto 1990. The strongest earthquake

with a magnitude of 5.3 was recorded in the region on the 13th April, 1969

with its epicentre close to Bhadrachalam. This earthquake was felt widely

even at Hyderabad, which is situated 200 km from epicentral region, and

caused considerable damage around Bhadrachalam. This earthquake was

followed by a number of aftershocks which were confined to a narrow zone of

10 and 20 km width, trending approximately NW -SE along the Godavari

Valley. The foci of the aftershocks were shallow and varied between 10 to 15

km. As per Map of India Showing Seismic Zones (IS-1893(Part-1)) the area is

located in Zone- II . Keeping the seismicity and seismo-tectonic set-up of area

in view it is suggested that suitable seismic coefficient be incorporated in the

designs of appurtenant structures of the scheme.

4.5 GEOLOGY OF THE PROJECT SITE

The Wainganga HE Project site was inspected on 21st January, 2004 and it

was observed that Wainganga river flows south / south-eastwards in the

project area with a width of about 1000 m in river reach.

The outcrops near river bed exhibit well developed local anticlinal and

synclinal folds with their fold axes trending NNW-SSE to NE-SE plunging 50

to 70 degrees towards NW. Finely banded character and close folding are

observed almost every where in these rocks. The rocks are brownish grey in

colour, fine grained, hard and compact and consist of alternate layers of either

magnetite or hematite and quartz. They vary considerably in width, from a few

millimeters to a few centimeters. These layers are of different colours, from

black through dark brownish red and light red to brown. The quartz in some

bands is cherty, in others it is relatively coarse-grained. The bands display


4-10

well developed joints and dislocate layers at places. Minute veinlets of quartz

and iron ore commonly cross the bedding. The laminae at places pinch out

sharply.

The dam site lies in a stable zone with shallow depth of overburden in the

river reach. The flat topography of the area has necessitated the provision of

a fairly long earthen dam. As the rocks is available at shallow depth, a positive

cut-off under the dam is recommended from seepage considerations.


5-1

CHAPTER–V

HYDROLOGY

5.1 INTRODUCTION

The Pranhita river with its three principal branches viz, the Penganga, the

Wardha and the Wainganga is the largest tributary of the Godavari river. The

Wainganga after its confluence with the Wardha is called the Pranhita. As per

Godavari Water Dispute Tribunal (GWDT) report, the Pranhita sub-basin

comprises of the catchment area of river Wainganga from its source to its

confluence with the Wardha and the Pranhita upto its confluence with the

Godavari. The map of the sub-basin and its line schematic diagram are given

at Plate 5.1 and Plate 5.2 respectively. The sub-basin excluding the Wardha

and the Penganga rivers has a catchment area of 61819 sq km.

The proposed Wainganga H.E. Project site is located downstream of

Gosikhurd project. The total catchment area at the proposed site is 43,658 sq

km while the catchment area of Gosikhurd is 34,862 sq km. Thus the free

catchment area between Gosikhurd and Wainganga H.E project site is 8,796

sq km.

5.2 DATA AVAILABILITY 5.2.1 Rainfall Data

Rainfall data of 41 raingauge stations in and around the sub-basin have been

considered for the present studies. The monthly rainfall data were obtained

from IMD from 1970 onwards till 1994-95 for majority of these stations. The

missing rainfall data has been estimated using standard statistical methods.


5-2

The weighted average monthly rainfall has been computed for the period

using Thiessen’s Polygon method for the entire sub-basin i.e catchment upto

Ashti G&D site having a catchment area of 50,990 sq.km. The weighted

monthly rainfall of Pranhita sub-basin, catchment upto Ashti G&D site, using

the Thiessen’s weights and station rainfall were calculated. Similarly monthly

catchment rainfall upto Wainganga H.E site have been computed using the

Thiessen’s weights of influencing stations upto the proposed H.E site.

5.2.2 Gauge and Discharge Data

There are twelve Gauge and Discharge sites maintained by CWC in Pranhita

sub basin. The Ashti G&D site maintained by CWC is located just upstream of

confluence of river Wainganga with river Wardha and is about 95 km

downstream of proposed Wainganga dam site. The discharge data from the

year 1965-66 onwards is available. However, data from 1970-71 onwards

has been utilized in the present studies. The catchment area at this G&D site

is 50,990 sq km which is 82.48 per cent of total catchment area of the sub-

basin. The data of this site has been used for developing the Rainfall-Runoff

model for the sub-basin and computing the runoff at the proposed H.E project

site.

5.3 UTILISATION

The planned utilisation from the existing projects in the Pranhita sub-basin

upto Wainganga H.E. Project is given below:


5-3

Table 5.1 Water Utilisation from Existing Projects

State Projects Annual Irrigation (ha)

Annual utilisation (MCM)

MP Major, 2 Nos. 37197 256

Medium, 13 Nos. 38690 272

Minors 28218 127

State Total 104105 655

Maharashtra Major, 3 Nos. 169252 1489

Medium, 19 Nos. 57936 278

Minor 109024 928

Total up to Wainganga H.E. Site 336212 2695

The planned utilisation of annual discharges for ongoing and contemplated

projects are utilised for this study. The actual utilisation data of existing major,

medium and minor projects upstream of Ashti G&D site have been taken from

NWDA study and WAPCOS’ study for Godavari basin. The upstream

utilisation are inclusive of evaporation losses. The regeneration due to

irrigation utilisation has been taken as 10 percent of utilisation on average

basis from existing major and medium projects. The seasonal and monthly

abstraction and regeneration at Ashti G&D site have been worked out and are

utilised in the study.

5.4 WATER AVAILABILITY STUDIES 5.4.1 Rainfall-runoff corelation

A Rainfall-Runoff model for each monsoon month has been developed by

regression analysis at the Ashti G&D site, using weighted catchment rainfall


5-4

and corresponding to the virgin flows for the period 1970-71 to 1994-95. The

best fitted equations / relations have been developed monthwise from June to

October.

5.4.2 Yield Assessment

Two alternatives have been considered for yield assessment as under :

Alternative I

Under this alternative, the monthly Rainfall-Runoff model developed for Ashti

G&D (CWC) site has been assumed to hold good at the proposed

Wainganga H.E. site as at this site the catchment area covers 82.48 percent

of the Pranhita sub-basin area. While assessing the catchment rainfall at

Wainganga H.E site, Thiessens polygons have been drawn using the

respective Thiessen weights. Rainfall series for each month have been

developed for the period 1970-71 to 1994-95. The virgin yields were then

computed using the monthly Rainfall Runoff model. The existing, ongoing

and proposed utilisations were then deducted to estimate the net annual

dependable flows at the Wainganga H.E site.

Alternative II

The observed monthly flows at Ashti G&D site were converted into virgin flows

at G&D site and reduced in catchment area proportion and catchment rainfall

proportion of Ashti G&D site and proposed H.E project site to yield virgin

flows and also net inflows at the proposed Wainganga H.E site.


5-5

The detailed computations of the yield study are presented in a separate

study “Hydrological studies for Wainganga H.E. Project”.

The dependable flows thus worked out under the two alternatives at

Wainganga H.E Project site are given as under :

Alternative I (M cum)

Alternative II (M cum)

50% dependable 6665.9 5527.9

75% dependable 3535.4 3269.7

90% dependable 2554.6 1932.4

The monthly yield series at Wainganga H.E. Project site from 1970-71 to

2001-02 are given in Annexure 5.1.

The Alternative II has been recommended as the net yields for this H.E.

project. This study is well within the limitations of the GWDT award. The

utilisation by this Hydro-electric project is of non-consumptive nature and does

not infringe any of the provisions of the award.

5.5 DESIGN FLOOD

The proposed Wainganga H.E. Project is located downstream of Gosikhurd

Project on the same river. The total catchment area above Wainganga H.E.

Project is 43,658 km2 out of which the catchment area 34,862 km2 is

intercepted by Gosikhurd Project. For this H.E. Project it is proposed to

estimate the flood by unit hydrograph approach and by Regional Flood

Frequency Analysis. The outflow hydrograph of Gosikhurd is routed at

Wainganga dam site and the flood for the intermediate sub-catchments


5-6

between Gosikhurd and Wainganga have been superimposed for the

combined effect.

5.5.1 Unit Hydrograph Approach

i) For the derivation of unit hydrograph, it is essential to use storms uniformly

distributed over the basin and producing direct runoff at uniform rate. For this

the large catchment area was sub-divided into sub catchments and the unit

hydrograph for each sub catchment was developed. The flood discharge at

the site is then estimated by combining the sub-basin floods, using flood

routing procedures. The inflow Hydrograph (PMF) having a peak flood 67,373

M3/Sec estimated for Gosikhurd Project is available in the Design Flood

Report of Gosikhurd Project. The inflow Hydrograph (PMF) at Gosikhurd is

assumed as outflow hydrograph for the purpose of estimating the flood at

proposed Wainganga H.E. Project.

The free catchment area of 8796 km2 between Gosikhurd and Wainganga H.E

sites has been divided into 4 sub catchments. The area of these 4 sub

catchments are as under :

Sub Catchment – I The catchment of Wainganga river between

Gosikhurd and Usarla has an area of 1195 km2.

Sub Catchment-II The catchment of Ghulband tributary between

Gosikhurd Soni has an area of 3101 km2.

Sub Catchment-III The catchment of Khobragarhi tributary upto the

confluence of Wainganga has an area 2156 km2.

Sub Catchment IV The catchment lying between Usarla and

proposed site of Wainganga H.E. Project has an

area 2344 km2.


5-7

CWC has carried out regional flood estimation studies for

hydrometeorologically homogeneous lower Godavari basin. On the basis of

rainfall and discharge data collected during monsoon for the gauged

catchments, representative one hour unit hydrographs have been developed

for each gauged catchment. The physiographic parameters of the catchment

and the parameters that describe their Unit hydrographs have been correlated

by regression analysis and equations for synthetic unit hydrograph for the

region are derived.

The Wainganga H.E. Project catchment lies in lower Godavari basin Sub zone

(3f). The relevant relationships are used and the parameters of unit

hydrograph for the above 4 sub-catchments are computed.

ii) The Probable Maximum Storm (PMS) value of one day for these 4 sub-

catchments are taken from Dam Safety Assurance and Rehabilitation Project

Generalised PMP Atlas “CWC” – March 1998. Similarly, the other basic

parameters adopted are the storm distribution based on IMD

recommendations for Gosikhurd project, base flow of 0.06 cumecs per sq km

and loss rate have been adopted based on Flood Estimation report of CWC.

The Probable Maximum Flood hydrograph is derived for each sub catchment

by convoluting the respective unit hydrograph and the incremental rainfall

excess from respective design storm. The computations for Probable

Maximum Flood and the parameters of Unit Hydrograph for each sub-

catchment have been calculated.

The outflow flood hydrograph at Gosikhurd dam site having a peak flood of

67,373 m3/sec has been routed between the reach Gosikhurd and Usarla.

The peak of routed flood works out to 65,236 m3/sec. There are 2 sub

catchments between Usarla and Gosikhurd namely; Sub-catchment I and


5-8

Sub-catchment No.II. The Probable Maximum Flood estimated for sub-

catchment No.I & II are added to the routed flood in order to estimate the

inflow at Usrala (Probable Maximum Flood hydrograph).

The flood hydrograph computed at Usarla site has been further routed in the

reach between Usarla and Wainganga dam site and the routed flood at

Wainganga site is computed as 63,329.2 m3/sec. There are 2 sub-

catchments between Usarla and Wainganga Dam sites namely; sub-

catchment No. 3 and sub catchment No. 4. The Probable maximum flood for

sub catchment No 3 & 4 have been estimated and are added to the routed

flood at Wainganga site to estimate the design flood (Probable Maximum

Flood) at Wainganga dam site which works out to 63,330 m3/sec.

Details of the computations are included in a separate report titled

“Hydrological Studies of the Wainganga H.E. Project”.

5.5.2 Flood Estimation by Regional Flood Frequency

The regional frequency curves are useful in estimating the flood for the

ungauged basins. Since such curves show the ratio of flood to the mean

annual flood against the return period, it is necessary to make an estimate of

the mean annual flood for the ungauged basin. A correlation is established

between the mean annual flood against the respective drainage areas of all

the gauging stations in the region. Homogeneity test is carried out for the

station in the region whose annual flood peak data are available. The station

which does not lie between the 95% confidence limit is not considered

homogenous. The flood for Wainganga H.E. Project has also been estimated

by required flood frequency method. 8 Nos. of the G&D stations in the

Pranhita and Wardha sub-basin have been considered in the regional

frequency analysis.


5-9

For the above G&D sites statistical checks such as; out lier test, stationarity

check, randomness check & chi-square test, etc. have been carried out

before adoption. All the above G & D stations lay between the 95%

confidence limit and hence these are homogenous.

The station frequency curve for various return period has been constructed for

G&D sites namely; Ashti, Bamni, Ghugus, Pauni and Sirpur by Gumbel’s

method using Frequency factor. The station frequency curve for stations

Tekra & Penganga have been constructed, using Chow’s Frequency Factor.

The Frequency Curve at Marlegaon has been constructed by Log-pearson’s

Type-III distribution.

The mean annual flood for 2.33 year return period is computed for all the 8

G&D stations from the respective frequency analysis curve. The ratio of

mean annual flood discharge for various return period of all the 8 G&D sites

have been worked out. From these ratios, the mean ratio of various return

period are worked out. A correlation between the Ratio of Peak Discharge

to Mean Annual Flood and the Return period is established in order to

construct the Regional Frequency curve. The control curves at 95%

probability have also been constructed.

The flood peak at Wainganga dam site has also been estimated by Station

Frequency Curve at Ashti G&D site on Pranhita river. The results of flood

computed for Wainganga Dam site by frequency Analysis are as under.

Details are given in the hydrology report under reference.


5-10

Return Period Station Frequency Curve M3/Sec.

Regional Frequency Curve

M3/Sec

.

100 yr. (Mean Curve) 32152 24591

(95% upper band) 40945 30266

500 yr. (Mean Curve) 40055 34650

(95% Upper band) 50736 41850

1000 yr. (Mean Curve) 42626 38435

(95% upper band) 55186 45900

10000 yr. (Mean Curve) 53081 50763

(95% upper band) 68537 57600

5.5.3 Recommended Design Flood

As per I.S. criteria-11223 of 1985 the inflow design flood for Wainganga H.E.

Project should be the Probable Maximum flood. The Probable Maximum

Flood of 63,330 m3/sec. is recommended for the design of spillway for the pre-

feasibility purposes. The flood studies will be revised after collection of

relevant short term discharge & storm data at the time of preparation of the

Detailed Project Report.

5.6 SEDIMENTATION

Wainganga H.E project is a storage project. Accordingly as per BIS 12181-

87, the sedimentation studies have been carried out to estimate the New Zero

Elevation expected after 70 years of siltation and the revised elevation area

capacity after 25 years of sedimentation. The New Zero Elevation after 70

years of siltation has been assessed as 208.4 m assuming a siltation rate of


5-11

4.78 Ha m/100 sq km/year as per CWC “Compendium on Silting of

Reservoirs”. The detailed sedimentation studies are included in a separate

Report on “Hydrological Studies for Wainganga H.E. Project”.

5.7 RECOMMENDATIONS & LIMITATIONS

(1) A G-D site need to be established near the proposed H.E project site

for realistic assessment of dependable yield and the design flood.

(2) A self recording raingauge station may also be established in the

catchment.

(3) Gosikhurd project is an ongoing project upstream of proposed

Wainganga H.E.Project. The series may alter slightly in short time

step after completion of the Gosikhurd project due to operating policy

of the Gosikhurd reservoir, but on annual basis, the variation in

dependable flows will be small.

S. No. Year June July Aug. Sep. Oct. Nov Dec Jan Feb Mar Apr May Annual1 1970-71 474.64 2511.46 6097.52 4752.37 536.37 131.91 61.53 48.38 28.50 34.75 21.05 23.03 14721.492 1971-72 281.77 381.61 596.83 1225.67 443.25 69.78 26.78 15.40 9.95 5.06 1.88 1.06 3059.043 1972-73 11.03 303.55 951.54 591.93 54.38 24.22 20.93 3.95 6.28 3.93 2.17 1.57 1975.464 1973-74 32.15 4161.49 3532.34 3137.22 1997.75 427.24 147.58 50.91 12.71 15.75 10.94 9.19 13535.285 1974-75 21.28 206.68 1251.73 126.74 299.78 82.02 22.99 8.78 7.62 7.77 2.73 0.95 2039.086 1975-76 1202.92 3069.26 5250.92 3648.51 1356.19 341.38 92.72 41.17 36.65 18.05 16.61 12.79 15087.187 1976-77 25.43 1197.21 1760.69 1702.54 34.07 68.44 28.49 16.88 9.37 8.13 5.20 4.99 4861.448 1977-78 606.52 2190.14 2689.27 3023.53 697.32 586.54 214.57 65.07 74.13 47.12 27.98 32.30 10254.499 1978-79 267.18 3165.69 6933.44 1886.42 304.78 101.19 164.25 53.58 182.92 209.76 11.06 13.77 13294.03

10 1979-80 369.13 606.12 2469.89 265.66 118.29 27.39 10.62 11.78 6.70 5.60 2.69 1.37 3895.2511 1980-81 259.79 1664.16 4680.10 2064.05 287.61 67.79 35.86 29.55 19.08 19.09 8.64 14.88 9150.5912 1981-82 274.68 2018.84 3892.36 2051.34 1002.90 179.56 62.70 43.04 45.07 21.69 15.72 12.41 9620.3213 1982-83 80.15 358.10 1136.73 471.60 178.09 81.59 18.30 12.78 7.12 6.50 1.43 2.10 2354.4814 1983-84 145.11 1371.35 4671.06 4722.72 1453.59 153.87 77.57 99.77 64.50 37.13 16.15 15.26 12828.0815 1984-85 52.22 411.46 2534.92 311.48 129.36 32.90 13.03 19.72 16.24 14.48 2.40 1.60 3539.8116 1985-86 58.04 381.65 2331.16 310.70 124.85 31.01 9.21 16.71 14.31 5.28 0.87 1.12 3284.9217 1986-87 843.04 2540.35 3802.78 559.84 191.06 88.35 45.51 66.51 32.13 37.88 25.34 6.85 8239.6418 1987-88 2.30 419.38 555.39 399.17 186.68 24.77 11.80 7.22 5.97 4.09 2.38 1.91 1621.0719 1988-89 240.67 1849.16 2070.23 1275.05 586.44 201.08 47.27 20.87 14.22 24.87 12.83 11.46 6354.1520 1989-90 104.01 380.76 644.30 431.63 110.53 33.41 5.74 1.84 3.88 2.18 0.91 8.58 1727.7921 1990-91 628.70 2857.61 3364.30 2596.79 1442.30 210.91 94.08 87.82 66.68 78.46 28.45 84.94 11541.0422 1991-92 82.00 1041.13 2830.11 1295.63 147.98 25.96 10.73 10.30 6.81 6.49 3.10 2.47 5462.7223 1992-93 116.29 681.92 4687.41 1063.95 122.51 31.98 23.66 16.34 17.74 16.49 2.04 5.35 6785.6824 1993-94 210.48 2325.35 3180.30 2148.57 1290.37 173.48 3385.92 59.26 34.59 18.32 15.99 9.82 12852.4525 1994-95 676.55 13159.58 10126.69 12349.87 1436.04 864.86 149.78 145.60 81.12 128.62 95.23 64.60 39278.5526 1995-96 102.22 1566.07 1309.44 1732.99 394.03 72.99 39.16 33.76 27.50 19.38 9.33 6.01 5312.9027 1996-97 64.09 343.31 795.96 471.81 142.90 48.65 13.84 13.68 8.94 5.08 3.25 2.41 1913.9228 1997-98 67.59 754.75 1443.40 1139.34 303.89 123.69 353.92 176.85 126.13 37.34 32.32 23.83 4583.0429 1998-99 107.38 710.55 1054.22 1874.63 364.73 298.09 65.40 45.35 31.09 24.23 14.53 12.93 4603.1130 1999-00 533.91 1085.50 4243.46 5996.60 2335.34 278.62 116.42 92.56 68.65 45.46 31.42 32.22 14860.1531 2000-01 130.58 1756.09 874.47 349.45 104.34 24.01 9.71 8.51 3.07 1.91 1.34 1.19 3264.6632 2001-02 853.94 1202.20 2708.43 346.03 383.06 44.83 20.60 11.62 9.21 6.73 4.13 2.46 5593.25

1932.383269.725527.99

90 % Dependable Yield75 % Dependable Yield50 % Dependable Yield

Annexure 5.1Monthly Yield Series at Wainganga H. E. Project

(in Catchment and rainfall proportion from Asti G&D Site) Units: Mm3


6-1

CHAPTER-VI

CONCEPTUAL LAYOUT AND PLANNING

6.1 INTRODUCTION Wainganga H.E. project envisages the construction of a 6030 m long and 32

m (above the deepest river bed level) high composite concrete gravity and

earthen dam located at longitude 79o 57’ 35” E and latitude 20o 23’ 0” N with

FRL at 222.4 m across Wainganga river near village Daungar Saungi on the

left bank of the river. The river bed level at the proposed dam location is 196

m (approx.). The power house is proposed at the toe of the power dam on the

right bank of the river. The project envisages the utilization of the maximum

gross head of 25.4 m and live storage of 5155 M cum between MDDL & FRL

to generate hydro-power with installed capacity of 105 MW (5x21 MW). A

tailrace channel 300 m long discharge the water back into Waingaga.

6.2 LAYOUT STUDIES

6.2.1 CEA in its initial planning had envisaged the construction of a 24.9 m high

dam with FRL at El 222.4 m & MDDL at El 214 m just downstream of

confluence of Khobragarhi with Wainganga where the river bed level is about

197 m. The power house was proposed to be a dam toe structure operating

under average gross head of 22.1 m with a firm power generation of 59 MW.

An optimum generating capacity of 150 MW was envisaged with annual

energy generation of 517 GWh and 687 GWh in 90% and 50% dependable

flow yield series respectively.

6.2.2 The dam site near Daungar Saungi is kept at the same location as specified in

CEA studies. At this site a composite concrete gravity structure in the main


6-2

river reach with earthen dams on both the flanks are proposed considering the

requirement of spillway, power house and total length of the dam in the valley.

6.2.3 Based on the toposheet studies and site visit by WAPCOS’ team the

alignment of dam axis has been optimally fixed so as to optimize the total

requirement of construction materials for earthen dams in the flanks. Based

on above, a kink in the alignment of dam axis has been provided in the right

flank.

6.2.4 The FRL of the reservoir has been fixed keeping in view the optimum

utilization of storages for power generation purposes as well as from

submergence considerations of main towns/settlements. Provision for dykes

for protecting main towns/settlements from the reservoir spread has also been

considered in formulation of the scheme.

6.2.5 The releases from the project are planned from power considerations, as no

irrigation schemes on main Wainganga are proposed downstream in near

future as per discussions with State Irrigation Authorities. However, some

irrigation schemes on the tributaries of Wainganga are proposed which may

not affect the functioning of Wainganga as a power project.

6.3 DIVERSION STRUCTURE

6.3.1 General

A 32 m high (above deepest river bed level) composite concrete gravity and

earthen dam is proposed as the main diversion structure near Daungar

Saungi village on river Wainganga. The dam is proposed to be located at

Latitude 20o 23’ 0” N and Longitude 79o 57’ 35” E. The dam is proposed to be

6030 m long with an ogee spillway 796 m long and two concrete non-


6-3

overflow blocks on right side of the spillway blocks of 20 m each. Five power

dam blocks and two NOF blocks of a total length of 140 m are proposed on

the right side of the spillway. An earthen section of 3648 m length with

maximum height 31 m shall be provided on the right flank and 1366 m long

earthen section with maximum height 32 m on left bank in view of the

availability of earth materials in the vicinity of dam site and in reservoir area.

Keeping in view the topographical features and the preliminary geo-technical

assessment of the alignment, the spillway is proposed to be located in the

main river reach.

The proposed dam shall have FRL at El 222.4 m, MWL at El 223.0 m and

MDDL at El 212.0 m. The top of dam is kept at EL 228.0 m with provision for

computed freeboard of 5.6 m above FRL. The maximum reservoir fetch has

been computed as 40 km. The proposed dam shall have a submergence area

of 87496.84 ha at FRL and a live storage of 5155 M cum between FRL and

MDDL.

6.3.2 Spillway Overflow Section

The length of the main dam at top is 6030 m which include spillway, concrete

non- overflow blocks, power dam blocks and earthen flank on either side of

the spillway. Gated ogee type of spillway with crest at EL 210 m and gate size

of 20 m x 12.5 m are proposed. The spillway and the concrete Non-overflow

(NOF) blocks are proposed to be founded on competent rock in the middle of

the river. The total length of the spillway is 796 m which comprises 33 bays of

20 m clear waterway, each separated by piers of 4 m thickness. The spillway

has been designed for routed PMF of 60656 cumec. Three number extra

bays have been provided over the required 30 number bays for additional

factor of safety on consideration of 10% gates inoperative as per codal

requirement. Considering the tail water conditions and the anticipated rock


6-4

condition at the dam site, stilling basin type of energy dissipation has been

proposed. The spillway is flanked by 2 nos 20 m long NOF blocks on left side

for providing wrap arounds of the dykes. On the right side of the spillway

power dams and two concrete NOF blocks have been provided besides

earthen dam sections on either side.

The spillway structure as well as NOF blocks have been zoned with different

grades of concrete. The spillway and NOF blocks are provided with a 6.0 m

wide road. Radial gates are provided for the spillway and the trunnion has

been located at an elevation above the maximum water profile over the ogee.

A foundation gallery of size 2.0 m x 2.5 m is proposed in the spillway and in

the NOF portion. The gallery will be located at a distance of 3.0 m above the

foundation level. The gallery will serve the purpose of foundation curtain

grouting and drainage and will also house the measuring instruments.

Details of “Typical Section of Concrete Dam” are indicated in Drg. No.

WAP/PFR/WAINGANGA/1005/R1.

6.3.3 Earthen Dam

About 5014 m length of the main dam will be zoned type earthen section with

a vertical central imperious core. 3648 m long earthen dam section with

maximum 31 m height shall be provided on the right flank and about 1366 m

long earthen section with maximum height 32 m shall be provided on left

flank.

The top level of earthen dam has been kept at El 228 m which is the same as

provided in the concrete Non-overflow sections. The top width is kept as 6.0

m. Vertical central impervious core with upstream and downstream slopes of


6-5

0.35 (H) to 1(V) is proposed with minimum top width of 3.0 m. The top of core

section is kept 2.0 m above the MWL. A graded inclined filter 1m thick is

provided in the downstream face of impervious core followed by horizontal

filter near the base to drain seepage water through the Rock Toe to the

longitudinal drain at the toe of Rock toe.

Upstream face is proposed to be protected by 1.0 m thick riprap extending

well below MDDL. Downstream face of the dam is protected by provision of

turfing from erosion considerations.

The earthen dam section has been provided with two rows of curtain grouting

in addition to any special treatment works for geological discontinuities

encountered, if any.

The maximum section has been checked for stability in accordance with the

relevant Indian standards. The earthen dam will be provided with requisite

instrumentation network. The details of Earthen dam sections are indicated in

Drg. No WAP/PFR/Wainganga-I/1004/R1.

6.4 POWER DAM

The length of the power dam blocks is 100 m with 5 blocks of 20 m length

each, and is located in the non overflow section on the right bank. This will

accommodate 5 Nos. power intakes with trashracks on its face. The deepest

foundation level is at El 196 and the maximum height from foundation to top of

dam is 32 m. The top width will be 6.0 m. The penstock of 5.0 m diameter are

embedded in the body of power dam.


6-6

6.5 POWER INTAKE

5 Nos. Intake structures for diverting the total design discharge of 595.82

cumec are proposed on the face of Power dam blocks on the right bank of the

river at NSL of El 200 m. The invert level of the intake trashracks is

proposed at El 202 m and the top of the trashrach is kept at El 222.4 m i.e at

FRL. The intake structure is assumed to have semicircular entrances with

intake emergency gate on upstream face of the dam & then a smooth gradual

transition from rectangular shape to the circular penstock.

The centre line of the intake at entry is proposed at El 206.0 keeping in view

the minimum water cushion requirement below the MDDL (El 212.0 m).

Though New Zero Elevation after 70 years is assessed as El 208.4, the

Centre line of intake is kept at El 206.0 m keeping in view the fact that

sedimentation studies do not take into account the ongoing upstream storage

project (Gosikhurd project). Further the provision of crest of spillway at El

210.0 m much below the FRL (El 222.4 m) would help in flushing of the

accumulated silt in the reservoir.

The velocity through 5.0 dia penstock is limited to around 7.5 m/sec. Provision

of a larger dia would have necessitated raising of the MDDL (from minimum

water cushion requirement) thereby reducing the live storage as the FRL can

not be raised beyond El 222.4 m from submergence considerations.

Five number inclined penstocks of diameter 5.0 m each, and 70 m long

through the body of the power dam are proposed. Provision of vertical lift

gates of size 5.5 m x 5.5 m is provided in the body of the power dam from

maintenance considerations. These gates will be operated by a gate hoisting

structure at El 228 m.


6-7

The details of Intake structure and Power dam block are indicated in Drg. no.


6.6 POWER HOUSE

The power house is located below the toe of the power dam in right flank.

This power house will have 5 units of 21 MW each operating under a

maximum gross head of 25.4 m. The rated head of turbines is proposed as

19.74 m. It is proposed to install 5 no. vertical axis Kaplan turbines in the

power house with centre line at El 194.7 m which is 2.3 m below the

minimum tail water level (El 197.0 m).

The power house building will be 20.5 m wide and 121 m long including

service bay of 25 m length. 1 Nos. EOT cranes of 150/15 tonnes capacity is

proposed to run along two crane beams supported on columns along B and

D lines.

A draft tube deck is provided at El 200.00 m with gate groove openings for the

draft tube gates. The hoisting mechanism for these gates would be by means

of a gantry provided with lifting beam. A suitable rail track will be provided for

movement of the gantry. A storage arrangement for the draft tube gates,

when not in use, will be provided in the form of grooves below the deck

approach. These groves will be located in the line of rail track for movable

gantry. The gates will be hung in these grooves and covered with chequered

steel plates.

The transformer deck will be provided upstream of main powerhouse building

for installation of transformers. The service bay will be approached by an

approach road connected to the nearest existing road.


6-8

The X-section and Plan of Power House are indicated in Drg. Nos.

WAP/PFR/WAINGANGA/1006/R1 & 1007/R1.

6.7 TAIL RACE

The tail waters from the draft tubes will be led to a tail pool. The bottom

elevation of tail pool near the draft tubes shall be at 185.9 m and the tail pool

floor will be given a reverse slope of 1 in 5 till it reaches an elevation of 196.0

m. The bottom of the tail pool will be designed for uplift pressure when

empty. Depending upon the site conditions either the base slab will be

anchored to the foundation rock (if available) or suitable underdrainage by

pressure release valves along with inverted filter will be provided.

After the tail pool a tail race channel shall be provided upto the river. This

tailrace channel about 300 m long will have a bed slope of 1:750 and a full

supply depth of 3 m. The tail race shall be a trapezoidal lined section with

bed width of 60.0 m and a side slope of 1 in 2.0 till it joins the river.

6.8 ELECTRICAL / ELECTRO-MECHANICAL WORKS

The proposed 105 MW WAINGANGA Hydro-Electric Project would be

Storage type development. The installed capacity would be provided by 5

nos. Kaplan, Vertical axis turbine driven generating units of 21 MW each

housed in a surface powerhouse. It is proposed to provide Inlet Valve of

Butterfly type for each turbine, which would be accommodated in the

powerhouse.

The generation voltage of 11 kV would be stepped up to 220 kV through three

phase 26 MVA, 11/220 kV step up transformer for each unit located adjacent

to upstream wall of the power house. The 11 kV isolated phase busducts


6-9

would connect the 11 kV generator terminals with 11 kV bushings of step up

transformers. The 220 kV bushings of the transformers would be connected

with 220 kV outdoor switchyard located near the power house.

The arrangement of generating equipments, unit step up transformers, etc. is

indicated in the drawings No. WAP/PFR/WAINGANGA/1006/R1 & 1007/R1.

The power generated would be evacuated through one double circuit 220 kV

transmission line. The single line diagram is shown in Drgs. No.


6.9 BRIEF PARTICULARS OF EQUIPMENTS 6.9.1 Turbine and Governor

The upstream levels, tailrace levels and heads available for power generation are indicated below: i) Upstream Levels

• FRL EL 222.4 m

• MDDL EL 212.0 m

ii) Tailrace Levels

• Maximum EL 198 m

• Minimum EL 197 m

iii) Heads

• Maximum net head 22.86 m

• Minimum net head 12.60 m

• Rated head 19.74 m


6-10

The specific speed of the turbine determined as 514 rpm corresponding to

head of 19.74 m leads to the choice of Kaplan turbine for this station. The

turbine would be suitably rated to provide 21 MW at generator terminals at

rated head of 19.74 M. The speed of turbine has been determined as 125.0

rpm. The centre of turbine runner has been set at EL 194.7 m, 2.3 m below

the minimum TWL which is at EL 197.0 m. The governor would be electro-

hydraulic digital PID type suitable for fully automatic control. The closing time

of wicket gates would be so adjusted so as not to increase the speed rise and

pressure rise more than 45% and 30% respectively under full load throw off

condition.

6.9.2 Main Inlet Valve

It is proposed to provide Inlet Valve of the Butterfly type for each turbine as

second line of defence in stopping the water flow to the turbine when due to

governor malfunctioning, the generating units may tend to go to runaway

speed. During the time when the generating unit is under stand still condition,

it would help in minimizing the water leakage through the wicket gates of the

turbine. The opening of the valve would be achieved through pressurized oil

servomotor and closing through counter weight.

6.9.3 Generator and Excitation System

The generator shaft would be directly coupled with the turbine shaft. The

bearing arrangement would be umbrella type with combined thrust and guide

bearings below the rotor only. The generator would be of the closed air circuit

water-cooled type. The main parameters of the generator would be as

indicated below:


6-11

i) Rated out put - 21 MW

ii) Power factor - 0.9 lag

iii) Speed - 125 rpm

iv) Class of Insulation of

stator and rotor winding - Class 'F'

v) Generation Voltage - 11 kV

The generators would be provided with static excitation equipment and

voltage regulator. Necessary power for excitation would be provided by

tapping the generator terminals. Necessary fire/temperature. detectors and

two banks of CO2 cylinder would be provided for fire protection of the

generator. Optimisation of generation voltage would need to be carried at

DPR stage.

6.9.4 Unit Step-Up Transformer

Three phase 26 MVA, 11/220 kV transformer, would be provided for each

generating unit . The transformers would be located outside near upstream

wall of powerhouse. The 11 kV bushing of the transformers would be

connected with 11 kV terminals of generator through 11 kV busducts. The 220

kV bushings would be connected with 220 kV outdoor switchyard located near

the upstream wall of powerhouse through link lines.

6.9.5 EOT Crane

The heaviest equipment which the powerhouse crane is required to handle

during erection and subsequently during maintenance is the generator rotor.

The weight of the generator rotor has been estimated to be about 120 tonnes.

It is proposed to provide the one EOT crane of 150/15 tonnes capacity each.


6-12

6.1.5 Auxiliary Equipment and Systems for the Power House

Following equipments for the auxiliary systems of the powerhouse would be

provided:

i) Cooling water system for turbines, generators, unit step up

transformers etc.

ii) Drainage System

iii) Dewatering system

iv) High pressure compressed air equipment for governor and MIV etc.

v) Low pressure compressed air equipment for station services

vi) 415 V LTAC supply system comprising station service transformers,

unit auxiliary transformer, station service board, unit auxiliary boards

etc.

vii) D.C. supply system comprising 220 V DC battery, chargers, DC

distribution boards etc.

viii) Ventilation system for the power house

ix) Air conditioning system for control room, conference room etc.

x) Illumination system

xi) Earthing system

xii) Oil handling system

xiii) Power and control cables

xiv) Fire protection system

6.10 20 KV SWITCHYARD

It is proposed to provide 220 kV Outdoor Switchyard on the upstream side

near the power house having 9 bays, 5 bays for generator incomings, 2 bays

for 220 kV transmission lines, 1 bay for step down transformer and 1 bay for


6-13

bus coupler. The double bus bar arrangement has been proposed which

would provide flexibility and reliability in the operation of the plant.

6.11 OBSERVATIONS OF CEA & CWC

The Draft Report of this project was submitted to CEA for perusal during

February ‘04. The observations from the various directorates of CWC and

CEA on the civil and electrical aspects have been considered and taken care

in this report. The detailing has been kept to the possible extent as the report

pertains to the preliminary feasibility stage studies.


7-1

CHAPTER – VII POWER POTENTIAL STUDIES

7.1 GENERAL

The power potential studies have been carried out for Wainganga Hydel

Scheme located in Maharashtra State. The projected power supply position

for 11th Plan indicates that there would be shortage of peak power in Western

Region. The execution of this project would help in reducing the gap between

supply and demand of power.

7.2 TYPE OF DEVELOPMENT

The project has been planned as storage based development. The features

of the scheme would be as follows :

- FRL EL 222.4 M

- MDDL EL 212 M

- Storage at FRL 5995.24 Mcum

- Storage at MDDL 840.24 Mcum

- Live Storage 5155.00 Mcum

The MDDL has been fixed keeping the requirement of minimum cushion of

water above the HRT to rule out air entrainment into the HRT. The FRL has

been determined to provide maximum feasible storage. The level v/s capacity

characteristics for the storage are indicated in Annex. 7.1.


7-2

7.2.1 Fixation of Tailrace Water Level (TWL)

The minimum tail water level (Minimum TWL) which corresponds to discharge

of one generating unit at 10% load has been determined as EL 197.0 M. The

Maximum TWL is fixed at EL 198 M which corresponds to discharge of water

with all the units running at full load and is 0.5 m higher than the FRL of

Samda H.E. Project which is being planed downstream of this Project.

7.3 WATER AVAILABILITY

The available data of water flows on 10 daily basis has been analysed in

Chapter No. 5 on “hydrology”. Water flows series for 31 years (1970-71 to

2000-01) has been utilized for power potential studies and is indicated in

Annexure 7.2.

The month wise data for the evaporation losses which has been used in

calculation of power potential, is given below :

Month Evaporation Losses (mm)

Jan. 85 Feb. 135 March 200 April 248 May 362 June 236 July 133 Aug. 109 Sept. 103 Oct. 113 Nov. 100 Dec. 75


7-3

7.4 TYPE OF TURBINE

Kaplan turbine is the appropriate choice in this case considering rated head of

19.74 m. The following efficiencies pertaining to Kaplan turbine driven

generating unit have been considered for power potential studies :

- Efficiency of Turbine - 93.5%

- Efficiency of Generator - 98.0%

- Combined efficiency of - 91.63%

turbine and generator

7.5 RESERVOIR SIMULATION STUDIES 7.5.1 The hydrology series from 1970-71 to 2000-01 has been considered to carry

out the Reservoir simulation studies on carry over basis. The reservoir levels

have been varied depending upon the quantum of water in the reservoir. Tail

Water Level as has been kept constant at average level of EL 197.5 M. The

friction losses in the water conductor system has been taken as 10%.

7.5.2 The pattern of water availability on monthly basis reveals that the water

availability in the month of June also corresponds to lean flow and the effect

of rains in increasing the water availability starts from the month of July

onwards. The hydrological year for reservoir simulation studies, therefore,

has been considered from the month of July to June.

7.5.3 The reservoir operation has been simulated to work out firm power based on

90% dependability criterion. Allowing two failures in total period of 31 years,

the optimum firm energy generation works out to 153.3 million units

corresponding to firm power capacity of 17.50 MW. The results are indicated

in Annexure 7.3.


7-4

7.6 INSTALLED CAPACITY 7.6.1 As discussed above, the firm power works out to be 17.50 MW. The peak

period is about 4 hours to supply power during peak hours, the installed

capacity would need to be about 105 MW. During lean flow period the plant

would run in peaking hours only. In rainy months, however the plant would

run for longer period depending upon the water availability.

7.6.2 Keeping in view the system requirement installed capacity of 105 MW is

considered optimum.

7.7 NO. OF GENERATING UNITS

Regarding number of units to be installed for the storage based scheme; there

are three options :

1. 3 units of 35 MW each

2. 4 units of 26.25 MW each.

3. 5 units of 21 MW each

Although the first and second options would be preferable from economic

consideration but there could be problems in transportation of generating

equipment for this low head plant. Third option of providing five units of 21

MW each may cost slightly more but it would increase the reliability of power

supply and provide more flexibility in part load operation, besides ease of

transportation due to relatively small size of generating units. Considering

above factors, it is proposed to select the third option i.e. 5 units of 21 MW

each.


7-5

The turbine would be suitably rated to provide 21 MW at generator terminals.

The speed of the generating unit has been determined as 125 rpm.

7.8 RESULTS OF STUDIES

Annual energy generation has been computed for all the 31 years (1970-71 to

2000-01) with installed capacity 105 MW and is indicated in Annex. 7.4

(page 1/31) to 7.4 (page 31/31). The annual firm power generation (excluding

failure years i.e. 1972-73 and 1989-90) is computed as 153.3 million units.

The average annual generation considering secondary energy generation

works out to 246.146 Million units. The result of power potential studies are

summarized in Annex. 7.3.

7.9 INCREASED GENERATION AT DOWN STREAM PROJECT DUE TO WAINGANGA

Due to regulated releases from Wainganga, it would be possible to have

increased generation at down stream projects at Samda (ROR scheme),

Ghargaon (Storage scheme), Khungara (ROR scheme) and Pranhita (Storage

scheme) projects.

7.10 CONCLUSION

Wainganga H.E. Project is proposed to be a storage based development.

Installation of 105 MW comprising of five units of 21 MW each, would be

necessary to derive optimum benefits. The project would afford average

annual energy generation of 246.146 million units. It would be possible to

have additional generation on the down stream projects due to regulated

releases from Wainganga H.E Project.


7-6

7.11 RECOMMENDATIONS FOR FURTHER STUDIES

The following additional study would need to be carried out at DPR stage :

i) The storage at FRL and MDDL should be computed with more

accuracy based on the data of topographic survey.

ii) The FRL should be optimized considering incremental costs of dam,

other works as well as addition expenditure to be incurred to mitigate

impact due to submergence v/s incremental energy generation.

iii) Tail rating curve should be prepared to change the Tail Water Level

corresponding to discharge from the turbine.

iv) Number of generating units should be optimised keeping in view the

transport limitations, and requirement of part load operations etc.


8-1

CHAPTER - VIII POWER EVACUATION

8.1 ABOUT THE PROJECT

The Wainganga HE Project is proposed on river Godavari in Maharashtra

State. The site is located at Latitude of 200 .30'. 00" North and Longitude of

800.15'. 00"East.

8.2 POWER SCENARIO IN MAHARASHTRA

Maharashtra is leading state in Power Development viz

- Highest installed capacity in country

- Biggest Transmission & Distribution network including 400 kV Ring

mains system linking 400 kV sub-stations for bulk power transmission

- Fully computerized load dispatch centers for data collection all over the

state for supervisory control and data acquisition (SCADA)

- 100% villages electrified in state

- Energization of highest number of Agricultural pumps (2327716) in the

country.

The power requirement in Maharashtra excluding Mumbai is served by

Maharashtra State Electricity Board (MSEB). The Mumbai area is served by

three power utilities Tata Power Company Ltd., BSES Ltd. and BEST. The

state utility known as Maharashtra State Electricity Board (MSEB) is the sole

responsible organization for management of electricity generation,

transmission and distribution in the state. The per capita energy consumption

in Maharashtra is 667 Kwh which is higher than all India average of 335 Kwh.


8-2

Power Finance Corporation is providing technical and financial assistance to

the Government of Maharashtra for power reforms. MSEB will be

restructured in order to promote and encourage efficiency, autonomy and

accountability in decision making and functional specialization. GOM

proposed to corporatize MSEB into separate generation, transmission and

distribution companies. To ensure managerial and operational autonomy in

new companies, GOM will ensure that Directors on the board of the

generation, transmission and distribution companies are appointed exclusively

on the basis of merit.

The transmission network of Maharashtra is given at Annexure 8.1.

The transmission company will be responsible for transmitting power from the

generating company(s) and other sources of generation available to the state

for further supply to the distribution companies. It will also look after the state

load dispatch enters.

8.3 STATE POWER SECTOR STATISTICS

The projected Energy requirement & Peak load for Maharashtra at the end of

9th and 11th plan is indicated as below :

Energy Requirement (MU)

Peak Load (MW)

Plan 2001-02

End of 9th Plan

2011-12

End of 11th Plan

2001-02

End of 9th Plan

2011-12

End of 11th Plan

82921 158229 13147 25087

The installed capacity available to state is as given below :


8-3

Share in Central Sector 2027.90 MW

State Sector 9772.52 MW

Private Sector 3409.80 MW

Total 15210.27 MW

MSEB has the largest Transmission & Distribution (T&D) network is the

country with 6.67 lakhs ckt. Kms. The energy sale has grown from346 MU in

1960-61 to an estimated 37,067 MU in 2001-02. MSEB has been able to

meet the base demand through improvement in generation efficiencies and

procurement of power but the state faces a shortage in meeting peaking

requirements.

The present condition of Peak Demand/Peak Met of Maharashtra is as

follows:

Period Peak Demand (MW)

Peak Met (MW)

Surplus/Deficit (MW) (%)

April-Nov. 2003 14211 11282 -2929 -20.6%

Similarly, the actual power supply position of Maharashtra is as below :

Period Requirement (MU)

Availability(MU)

Surplus/ Deficit (-) MU

Surplus/ Deficit

(%)

April-Nov. 2003 56558 51423 -5135 -9


8-4

8.4 ARRANGEMENT FOR EVACUATION OF POWER FROM WAINGANGA HEP

The 105 MW power generated at 11 kV at Wainganga HEP will be stepped

upto 220 kV by unit step-transformers. The power would be transmitted to the

proposed 220/132 kV sub-station near Chandrapur which would be connected

to state grid.. Proposed line from Wainganga H.E.P for evacuation of power

is shown at Annexure-8.2.

8.5 ROUTE LENGTH AND COSTING OF 220 KV TRANSMISSION LINE FOR EVACUATION OF POWER FROM WAINGANGA HEP

The power of this project is intended to be evacuated by proposed 220 kV

D/C line to newly proposed 220/132 kV sub-station near Chandrapur. The

length of line has been estimated as about 85 km (220 kV D/C line) from

Wainganga to newly proposed sub-station near Chandrapur. The cost of this

line is estimated as Rs. 29.75 Crores.


9-1

CHAPTER – IX INITIAL ENVIRONMENTAL EXAMINATION STUDIES

9.1 INTRODUCTION

The Initial Environmental Examination of Wainganga hydroelectric project has

following objectives through various phases of development which are

proposed to be covered:

• provide information on baseline environmental setting;

• preliminary assessment of impacts likely to accrue during construction

and operation phases;

• identify key issues which need to be studied in detail during

subsequent environmental studies

It is essential to ascertain the baseline status of relevant environmental

parameters that could undergo significant changes as a result of construction

and operation of the project. In an Initial Environmental Examination (IEE)

study, baseline status is ascertained through review of secondary data,

reconnaissance survey and interaction with the locals.

The Preliminary Impact Assessment conducted as a part of IEE Study, is

essentially a process to forecast the future environmental scenario of the

project area that might be expected to occur as a result of construction and

operation of the proposed project. The key environmental impacts which are

likely to accrue as a result of the proposed developmental activity are

identified. Various impacts, which can endanger the environmental

sustainability of a project, are highlighted for comprehensive assessment as a

part of next level of environmental study during detailed studies.


9-2

9.2 ENVIRONMENTAL BASELINE SETTING

The study area covered includes the area within 7 km radius of various project

appurtenances. The data was collected through review of existing documents

and various engineering reports and reconnaissance surveys.

The various parameters for which baseline setting has been described have

been classified into physio-chemical, ecological and socio-economic aspects.

9.2.1 Physio-Chemical Aspects a) Water Quality

The proposed hydroelectric project lies on river Wainganga. Apart from

sewage generated from settlements in the catchment area, there are no major

sources of water pollution. The loading from the sewage generated by

various settlements, is not very high as compared to the water available in

river Wainganga for dilution. The water quality is characterized by low BOD

and COD and high DO levels. Likewise, various cations and anions are within

permissible limits. Thus, overall water quality is excellent. It is possible that

bacteriological levels could be high at few locations, just downstream of the

confluence of drains carrying effluent from various settlements. In recent

times, no major epidemic related to water-borne diseases has been observed.

Thus, water of river Wainganga can be used for domestic use after

disinfection, without conventional treatment.

b) Landuse

The submergence area of the project is 87,500 ha. As per the IEE study, both

forest as well as private land are coming under submergence. In addition to


9-3

above, land will also be required for siting of other project appurtenances,

infrastructure, project colony, labour camp, etc. The ownership category of

land required for various project appurtenances can be ascertained, once

project layout is finalized as a part of DPR preparation. Based on the type of

land (vis-à-vis ownership) being acquired, appropriate compensatory

measures can be recommended as a part of EIA study.

9.2.2 Ecological Aspects a) Vegetation

The major vegetation category observed in the project area and the study

area is scrub land. The major vegetation in the area is scrub and dense mixed

forest. The major forest blocks coming within reservoir submergence is given

in Table-9.1.

TABLE-9.1 Major reserved forest blocks coming within submergence area

Forest block Vegetation type

Right Bank

Murjha Reserved Forest Fairly dense and open mixed forest

Brahmapuri Reserved Forest Dense mixed forest

Gumgaon Palgaon Reserved Forest Fairly mixed forest


9-4

Left Bank

Armori Reserved Forest Fairly dense mixed forest

Charbatti Reserved Forest Fairly dense mixed forest

Amgaon Reserved Forest Fairly dense mixed forest

The vegetation in the area is categorised as southern dry mixed deciduous

forests. The density of forests is low. Human interferences in the area have

resulted in degradation of forests, especially areas in vicinity to settlements or

villages. The main tree species observed in the area are Arjun, Ain, Bija,

Mahua, Garadi, Ghoti, Mowai, Teak, Palas, Pipal, etc. In drier localities, with

lesser moisture content, Palas and Khair species are observed.

The understorey in these forests comprises of species such as Ghont,

Karonda, Kharata, Jilbili, Bamboo, etc.

The major floral species observed in project and study area is outlined in

Table-9.2.

Table-9.2 Major floral species observed in project and study areas

Local Name Botanical Name

Trees Mowai Lannea grandisa

Ain Terminalia tomentosa

Palas Butea monosperma

Ghoti Zizyphus xylophyra


9-5

Bija Pterocarpus marsupium

Khair Acacia catechu

Pipal Ficus religiosa

Mango Mangifera indica

Garadi Cleistanthus collinus

Mahua Madhuca indica

Semal Bombax ceiba

Shrubs Karonda Carissa sp.

Kharata Dadonaea viscosa

Bamboo Dendrocalamus strictus

Garshukri Grewia girsuta

Jilbili Woodfordia floribunda

b) Fauna

The density of forests in the project area is not very high, as a result of

interferences due to human population in the area. This is the main factor

resulting in low faunal population in the project as well as study areas. Based

on the field observations and interaction with the locals and Forest

Department, major faunal species reported in the area include tiger, leopard,

jungle cat, wolf, jackal, wild dog, deer, langur, etc. In plain area, Nilgai is fairly

common. Amongst the reptiles, snakes including the poisonous snakes e.g.

Cobra, Bungarus, Viper, etc. are reported in the project area and its

surroundings. Likewise, non-poisnous snakes e.g. Lycodon, Oligodon, etc.

are also reported from the area. Various types of lizards, e.g. common

monitor lizard, garden lizard are also reported in the area.


9-6

The commonly observed bird species in the area are heron, egret, stork,

coromorant, spoonbill, etc.

The list of major faunal species reported in the project area and its

surroundings is given in Table-9.3.

TABLE-9.3

Major faunal species observed in the study area

Local Name Zoological Name Schedule as per wildlife

protection act

Mammals

Tiger Panthera tigris

Spotted deer Axis axis

Leopard Panthera pardus Schedule-I

Sambar Cervus unicolor

Langur Presbytis entellus Schedule-I

Wild boar Sus scrofa

Sloth bear Melurus ursinus

Blue bull Boselaphus tragocamelus

Wild dog Cuon alpinus

Reptiles

Common Lizard Hemidactyles brooki

Monitor Lizard Veranus bengalensis Schedule-I

Python Python molurus

Cobra Naja naja

Viper Vipera russelli


9-7

Avi-fauna

Coromorant Phalacrocoran carbosinesis

Large Egret Ardea alba

Purple Heron Ardea purpurea-purpurea

Stork

Sponibill Platalea leucorodia

Little egret Egretta garzetta

Openbill stork Anastomus oscitans

Grey shirke Lanius excubitor

King crow Dicrurus adsimillis

It can be observed, that many of the faunal species belong to Schedule-I

category. As per Wildlife Protection Act (1972), such species are akin to rare

and endangered species and need to be conserved. Thus, it is essential to

ascertain adverse impacts on such species due to the proposed project, and

formulate management measures for amelioration of adverse impacts.

c) Fisheries

The major water body in the project area is river Wainganga, which is a

perennial river. During discussions with the Fisheries Department and local

villagers in the project area and its surroundings, presence of various fish

species including Catla, Rohu, Mrigal, Murrel, Wallagu, etc. was confirmed.

Pond and tank fishery is also practiced in this area. There are a large number

of fishing ponds/tanks within the study area. Major species cultured in ponds

and tanks are Rohu, Catla, Mrigal. Likewise, silver carp & grass carp are also

being cultured in few of the fishing ponds and tanks.


9-8

It is recommended that a detailed fisheries survey be conducted in the river as

a part of EIA study to ascertain the spatio-temporal occurrence of various

riverine fisheries. Presence of migratory fish species, if any, too needs to be

ascertained.

The list of major fish species observed in river Wainganga are given in Table-

9.4.

TABLE-9.4

Major fish species reported in river Wainganga

Local Name Scientific name

Catla Catla catla

Rohu Labeo rohita

Mrigal Cirhhinus mrigala

Prawn Macrobrachium malcamsoni

Murrels Puntius sarana

Cyprinus Labeo bata

Mystis Mystis sp.

Wallago Wallago attu

Clarius

Labeo Labeo fimbriatus

Calabasu Calbasu reba

Chella Chella bachella

Common carp Cyprinus carpio

Silver Carp Thirmethrix molitrix

Grass Carp Ctenopheringodon idella


9-9

9.2.3 Socio-economic Aspects

It is imperative to study socio-economic characteristics including demographic

profile of the project area and the study area. The proposed project site and

study area lie in Tehsil Chandrapur, district Chandrapur and Tehsil

Charchiroli of Gharchiroli district in Maharashtra. The demographic profile of

the study area villages is given in Table-9.5. Based on the Census data, total

population of the study area is 64,690. The average family size is about 5.

The female population is lower than the male population, which is reflected in

the sex ratio (i.e. number of females per 1000 males) of 957. The dominant

caste category in the study area villages is General Category as they account

for 79.4% of the total population. The Scheduled Castes and Scheduled

Tribes account for 9.8% and 10.8% respectively of the total population. The

literacy rate in the area is quite low (29.2%). The male and female literacy rate

in the study area is 44.6% and 12.9%. The low literacy rate in the area is one

of the indicators reflecting the socio-economic backwardness of the area.

Table-9.5 Demographic profile of the study area villages

Population Literates Name of village

House hold Male Female Total

SC ST Male Female

Wasa 405 1973 1020 953 357 349 505 19

Porla 1032 5084 2630 2454 503 343 1330 429

Mohazari Patch 42 204 109 95 - 59 20 2

Navargam 89 420 201 219 - 73 101 37

Wasa Chak

No.1

36 225 123 102 23 2 - -

Wasa chak

No. 2

Uninhabited

Churmusa 343 1763 877 886 122 16 303 94


9-10

Population Literates Name of village

House hold Male Female Total

SC ST Male Female

Surya Dongri 37 256 120 136 73 - 53 17

Kitali 229 1178 615 563 148 26 262 56

Akapur Chak 140 682 342 340 - 210 111 26

Dongar

Sawangi

276 1538 775 763 182 636 234 64

Deolgam 374 1747 897 850 118 488 384 92

Injewari 345 1902 939 963 327 81 501 161

Peth Tukum 122 618 336 282 90 281 112 47

Pevati 5 11 8 3 - 2 2 -

Saigaon 206 1137 591 546 25 55 282 96

Shivni Bk. 395 2160 1100 1060 81 3 552 196

Dongargaon 365 2184 1098 1086 109 25 490 179

Thanegaon 699 3586 1803 1783 276 471 739 181

Wasala 661 3405 1752 1653 429 148 873 223

Wanki 156 873 474 399 182 73 201 47

Total 5957 30946 15810 15136 3035 3341 7055 1966

Source : Census Data

9.3 PREDICTION OF IMPACTS

Based on the project details and the baseline environmental status, potential

impacts as a result of the construction and operation of the proposed project

have been identified. As a part of IEE study, impacts on various aspects listed

as below have been assessed:

- Land environment

- Water resources

- Water quality


9-11

- Terrestrial flora

- Terrestrial fauna

- Aquatic ecology

- Noise environment

- Ambient air quality

- Socio-economic environment

9.3.1 Impacts on Land Environment a) Construction phase Quarrying operations

A hydroelectric project requires significant amount of construction material,

which needs to be extracted from various quarry sites. The construction

material requirement includes abstraction of materials from quarries as well as

borrow pits. Normally quarrying is done along the hill face, and is generally left

untreated after extraction of the required construction material. These sites

can become permanent scar on the hill face and can become potential source

of landslides. This aspect needs to be covered as a part of the EIA study and

suitable measures for stabilization of quarry sites need to be recommended. It

is recommended that the existing quarry sites be tapped. To the extent

possible muck and waste generated during quarrying can also be used for

meeting the requirement of construction material. This will also depend on

their engineering properties. If new quarries have to be opened, then they

need be located over non-forest land so as to minimize adverse impacts on

flora & fauna are to the extent possible. Another recommendation is that

quarry sites be located away from human settlements, if possible, so that

human population in the area is not adversely affected.


9-12

Likewise, significant amount of material will be excavated from borrow areas

which need to be properly managed after excavation of construction material.

If these sites are left without reclamation, they can disrupt natural drainage

pattern, and can serve as breeding habitats for mosquitoes, leading to

increased incidence of vector-borne diseases.

Operation of construction equipment

During construction phase, various equipment will be brought to the site.

These include crushers, batching plant, drillers, earth movers, rock bolters,

etc. The siting of these construction equipment would require significant

amount of space. Similarly, space will be required for workshop, storing of

other construction equipment and materials, etc. In addition, land will also be

temporarily acquired, for storage of the quarried material before crushing,

rubble, sand, crushed material, cement, spare parts yard, fuel storage, guard

room, parking of light and heavy vehicles, petrol and diesel pumps,

temporary and permanent residential colonies for government and

contractor’s labour, water supply and switch yard for construction purposes,

etc. Various storage sites need to be earmarked for this purpose. It is

recommended that to the extent possible, such sites are located over non-

forest land. Based on the discussions with the Forest Department, such sites

can be located in areas where faunal density is less, and are away from

habitats of various faunal species observed in the area.

Construction of roads

Significant vehicular movement for transportation of large construction

material, heavy construction equipment is anticipated during construction

phase. Many roads in the project area would require widening. Many new

roads also would have to be constructed. Construction of new roads may lead


9-13

to removal of trees on slopes and re-working of the slopes in the immediate

vicinity of road, which may lead to landslides, soil erosion, gully formation, etc.

Adequate management measures need to be implemented to ameliorate such

adverse impacts. The length of various roads to be constructed and their

alignment can be finalized as a part of DPR preparation. Based on the

alignment, severity of impacts can be assessed and suitable management

measures can be formulated. The other impacts due to construction of roads

could be land acquisition, air pollution during construction. Specific

management measures need to be implemented for mitigation of these

adverse impacts as well.

b) Operation Phase

The area coming under reservoir submergence is 87,500 ha. The

submergence area entails acquisition of forest area and private land in

various settlements, both on the left and right bank sides. Additional area will

be required for siting of various project appurtenances, infrastructure, etc. The

density in the forests of the project area is generally low. However, it is

recommended that ownership status of land to be acquired for various project

appurtenances be ascertained and to the extent possible non-forest land be

acquired. Another criteria for selecting such sites could be that they are

located at some distance from the human settlements.

As a part of next phase of Environmental study, it is recommended that

detailed studies be conducted to ascertain the ownership status of these

lands, i.e. whether the land belongs Forest Department or is it a non-forest

government land. Even barren or scrub land, could be categorized as forest

land, if it is under the jurisdiction of forest department. In such a scenario,

compensatory afforestation as per the norms of Forest Conservation Act


9-14

(1980) will have to be done in lieu of entire forest land as per ownership,

irrespective of its vegetal status to be acquired for the project.

Based on the type of land being acquired for the project, suitable

compensatory measures can be suggested as a part of EIA study.

9.3.2 Impacts on Water Resources

The diversion of discharge for hydropower generation generally leads to

reduction in flow downstream of the dam site up to the confluence point of tail

race discharge. However, in the proposed project, dam toe power house is

envisaged. Thus, no significant impact on this account is anticipated. The dam

would reduce the peak flood as a result of reservoir routing. The dam would

moderate the variations in flow extremes as a result of reservoir routing in the

dam.

9.3.3 Impacts on Water Quality a) Construction phase

Effluents from labour camps

The project construction is likely to last for a period of 4-5 years, apart from

investigation stage. About 4,000 workers and 1,000 technical staff are likely to

work during project construction phase. The construction phase, also leads to

mushrooming of various allied activities to meet the demands of the immigrant

labour population in the project area. Thus, the total increase in labour

population during construction phase is expected to be around 10000-12,000.

The total quantum of sewage generated is expected to be of the order of 0.8

mld. The BOD load contributed by domestic sources will be about 540 kg/day.


9-15

The sewage generally shall be disposed in nearby streams or channels

through open drains, which can lead to deterioration of water quality of

receiving water bodies, if the same is disposed without treatment. This can

lead to increased incidence of water-borne diseases especially, if the water

from such water bodies is consumed without treatment. Thus, it is

recommended to commission adequate sewage treatment facilities in the

labour camps.

Normally, during construction phase, elaborate sewage treatment facilities

including primary and secondary treatment units are not commissioned, as

they remain unutilized, once the construction phase is over. At various

construction sites, septic tanks and or other low cost sanitation units are

developed. Similar sewage treatment measures are envisaged in the labour

camps of the proposed project as well.

Effluent from crushers

During construction phase, at least one crusher each will be commissioned at

the dam and power house sites. Water is required to wash the boulders and

to lower the temperature of the crushing edge. About 0.1 m3 of water is

required per tonne of material crushed. The effluent from the crusher would

contain high suspended solids. The effluent, if disposed without treatment can

lead to marginal increase in the turbidity levels in the receiving water bodies.

However, no major adverse impacts are anticipated due to small quantity of

effluent and availability of sufficient water for dilution. The severity of impacts

would vary from season to season with variations in water availability of

dilution. It is recommended to provide a settling tank to treat the effluent from

crushers before disposal. The settling tank can also be used to treat runoff

carrying high turbidity levels from the construction sites.


9-16

b) Operation phase Effluent from project colony

In the operation phase, about 200 families will be residing in the area which

would generate about 0.15 mld of sewage. The quantum of sewage

generated is not expected to cause any significant adverse impact on riverine

water quality. Adequate sewage treatment facilities including secondary

treatment facilities in the form of oxidation ditch or aerated lagoon needs to be

commissioned for this purpose to ameliorate the marginal impacts. The type

of treatment units that need to be installed can be finalized, based on

topography, population served, etc. It is recommended that the project colony

could be located over non-forest land. This is necessary to minimize the

diversion of forest land for various project appurtenances.

Impacts on reservoir water quality

The flooding of forest and agricultural land in the submergence area increases

the availability of nutrients resulting from decomposition of vegetative matter.

Enrichment of impounded water with organic and inorganic nutrients at times

become a major water quality problem immediately on commencement of the

operation and is likely to continue in the initial years of operation. Since, in the

proposed dam, significant quantity of forest area and private land including

agriculture land, is coming under reservoir submergence, it is recommended

that a detailed modelling study be conducted to estimate the D.O. level in the

reservoir during its initial years of operation.


9-17

Eutrophication risks

The fertilizer use in the catchment area intercepted at the dam site is low.

Since, the present proposal envisages only hydropower generation and does

not entail any command area development, problems of eutrophication, which

are primarily caused by enrichment of nutrients in water are not anticipated.

9.3.4 Impacts on Terrestrial Flora

a) Construction phase Increased human interferences

As mentioned earlier, about 5,000 technical staff, workers and other group of

people are likely to congregate in the area during the project construction

phase. The total increase in population is expected to be about 10,000-

12,000. Workers and other population groups residing in the area may use

fuel wood, if no alternate fuel is provided. On an average, the fuel wood

requirements will be of the order of 5,000-5,400 m3. Thus, every year, fuel

wood equivalent to about 1600-1800 trees will be cut, if no alternate sources

of fuel are provided. Since, tree density is not very high in the area, adverse

impacts due to cutting of trees to meet fuel wood requirements shall be quite

high. It should be made mandatory for the contractor involved in project

construction to provide alternate source of fuel to the labour population.

Alternatively, community kitchen using LPG or kerosene as a fuel can also be

run at various labour camps. Such community kitchens are now quite

common and have been successfully run during construction phase of various

projects. It is recommended that labour camps/colonies are located over non-

forest land.


9-18

b) Operation Phase Acquisition of forest land

About 87,500 ha of area is coming under reservoir submergence leading to

acquisition of forest land in various forest blocks. A part of the forest land to

be acquired is reserve forest land, for which conservation plan in addition to

compensatory afforestation measures need to be implemented. In addition to

reservoir submergence, additional land will also be required for siting of

construction equipment, storage of construction material, muck disposal,

widening of existing roads, construction of new project roads, infrastructure

development.

It is recommended that a detailed ecological survey be conducted as a part of

EIA study to assess the density and diversity of flora in the area to be

acquired for the project. It is also recommended that as a part of EIA study,

ownership status of land being acquired. For forest land, irrespective of the

density of vegetal cover, appropriate management measures, e.g.

compensatory afforestation need to be implemented.

9.3.5 Impacts on Terrestrial Fauna a) Construction phase The forests in the project area and its surroundings provides habitat to various

faunal species, quite a few which are categorized as Schedule-I, as per the

Wildlife Protection Act (1972), which have to be protected and conserved. As

a part of the EIA study, detailed data collection from various sources needs to

be done to assess the severity of impacts due to various activities in the

construction and operation phases on Schedule-I species and other faunal


9-19

species as well. During interaction with the Forest Department, it was

confirmed that no major wildlife in the project area and its surroundings. As a

part of the EIA study, it is recommended that presence of various faunal

species be ascertained, based on the available data with the Forest

Department. Various labour camps and other project appurtenances should

be located away from areas providing habitats to wildlife population. Impacts

on migratory route, if any during project operation phase also need to be

assessed. Based on the findings of the EIA study, suitable measures as a part

of Environmental Management Plan can be formulated.

b) Operation phase

During project operation phase, accessibility to the area will improve due to

construction of roads, which in turn may increase human interference leading

to marginal adverse impacts on the terrestrial ecosystem. The increase in

human population is not expected to be large, hence, significant impacts on

this account are not anticipated.

9.3.6 Impacts on Aquatic Ecology a) Construction phase

During construction of a river valley project, huge quantity of waste is

generated at various construction sites, which if not properly disposed,

invariably would flow down the river during heavy precipitation. Such condition

can lead to adverse impacts on the development of aquatic life, which needs

to be avoided by implementing appropriate techniques for their disposal.

The increased labour population during construction phase, could lead to

increased pressure on fish fauna, as a result of indiscriminate fishing by them.


9-20

Adequate protection measures at sensitive locations, identified on the basis of

fisheries survey in the EIA study need to be implemented.

b) Operation phase

Impacts on riverine fisheries

Amongst the aquatic animals, it is the fish life which would be most affected.

The diversion of water for hydropower generation could lead to adverse

impacts on riverine fisheries. However, in the proposed project, dam toe

power house is envisaged. Hence, adverse impacts on riverine ecology due to

reduction in flow downstream of the dam site are not anticipated. Based on

data collection as a part of the present study, migratory fish species are not

reported from the project area. As a part of EIA study, it is necessary to

conduct survey in the study area ascertain the presence and occurrence of

various fish species in river Wainganga. Based on the findings of the study,

adverse impacts can be assessed, and if required, suitable management

measures, need to be formulated.

Increased potential of reservoir fisheries

With the construction of dam, and creation of reservoir area of 87,500 ha,

there will be an increased potential of reservoir fisheries. The total fish

production from reservoir could be of the order of 26,000 tonnes/annum. The

reservoir can be stocked by Fisheries Department. The various fish species

which can be cultured include Catla, Rohu, Mrigal, grass carp, common carp,

etc. For development of fisheries it would be desirable to encourage such

activities through cooperative societies. Some of the Project Affected Families

could be rehabilitated as fishermen, and can be given fishing rights for

catching fish from the reservoir.


9-21

9.3.7 Impacts on Noise Environment

Increased noise levels are anticipated only during construction phase due to

operation of various equipment, increased vehicular traffic and blasting etc.

Quite a few human settlements are located close to the project site. Increased

noise level, especially blasting could scare away wildlife from the area. It has

been observed during construction phase of similar projects, that wildlife

migrates from such areas and returns after the cessation of construction

activities. Similar phenomenon is expected in the proposed project site as

well. However, presence of Schedule-I species in the project area, location of

various settlements around construction sites, makes its imperative to conduct

detailed noise modelling studies as a part of EIA study. Based on the

increased noise levels, as estimated through modelling studies, impacts on

human and faunal population in the area adjacent to various project sites

needs to be assessed.

9.3.8 Air Pollution Pollution due to fuel combustion in various equipment

Normally, diesel is used in construction equipment. The major pollutant which

gets emitted as a result of diesel combustion is SO2. The SPM emissions are

minimal due to low ash content in diesel. Model studies conducted for various

projects with similar level of fuel consumption indicate that the short-term

increase in SO2, even assuming that all the equipment are operating at a

common point, is quite low, i.e. of the order of less than 1µg/m3. Hence, no

major impact is anticipated on this account.


9-22

Emissions from various crushers

The operation of the crusher during the construction phase is likely to

generate fugitive emissions, which can move even up to 1 km along the

predominant wind direction. During construction phase, one crusher each is

likely to be commissioned at the dam and the power house sites. During

crushing operations, fugitive emissions comprising of the suspended

particulate will be generated. Based on past experience in similar projects,

significant adverse impacts on this account are not anticipated. However, it is

recommended that the labour camp be situated at least 1 km away from the

construction sites and that too on the leeward side of the pre-dominant wind

direction in the area.

9.3.9 Impacts on Socio-Economic Environment

a) Project construction phase

The construction phase will last for about 4-5 years. Those who would migrate

to this area are likely to come from various parts of the country mainly having

different cultural, ethnic and social background. Due to longer residence of

this population in one place, a new culture, having a distinct socio-economic

similarity would develop which will have its own entity. It is recommended that

labour camps/colonies be located over non-forest area.

Normally during construction phase of a project, there is significant impact on

the employment potential of the area. Many people migrate in the area in

search of jobs. The present population in the study area villages is of the

31,000. About 4,000 workers and 1,000 technical staff are likely to work

during project construction phase. The total increase in labour population

during construction phase is expected to be around 10,000-12,000.Thus,

population is going to increase by about 35% to 40% in the area during


9-23

construction phase. This can lead to significant impacts on the existing

infrastructure facilities in the area. Thus, adequate infrastructure needs to be

developed to cater to the requirements of the migrating labour population in

the area.

b) Project operation phase Acquisition of private land and homesteads

The area coming under reservoir submergence is 87,500 ha. The

submergence area entails acquisition of unclassified forests and reserve

forest blocks. Private land including homesteads in various settlements, both

on the left and right bank sides too shall also be acquired. Various settlements

likely to be fully or partially affected are listed in Table-9.6.

Table-9.6

List of settlements losing land under reservoir submergence

___________________________________________________________________

Right bank Left Bank

Halda Soi

Avalgaon Virsi

Wandra Bangaheti

Dorli Pulgaon

Chichgaon Rawi

Baradkinni Kandhala

Gangalwari Athili

Talodhi Asola


9-24

Sargaon Khaira Chapral

Vilam Saungi

Kolari Parsari

Belgaon Phungaon

Bondegaon Dakasarandi

Khandola Opara Ka Tola

Kahargaon Opara

Nandgaon Bhagri

Bhaleshwar Cicholi

Chikkalgaon Mandhar

Hardoli Lachandur

Surbari Arun nagar

Chichoti Ekalpur

Sawalgaon Kosi

Sonegaon Wadhona

Bodigaon Gangoli

Nilaj Kharkhada

Panchgaon Ghati

Rui Churmura

Belpatri Khari

Mangali Akapur

Chakgawarla Dongar saunghi

Jugnala Devalgaon

Bothdichak Kitari

Ranbothli Thanagaon

Sawardandkhak Sitabandi

Dhanolpohachak

Maldongri

Beldati


9-25

Bramhapuri

Parsori

Jhilbori

Nawargaon Makta

Kathorla Makta

Kurjha

Vidyanagar

_________________________________________________________________

Some of the villages listed in Table-9.6 could be part of a revenue village.

Hence, the actual number of affected revenue villages would be lesser than

the number of villages listed in Table-9.6. A detailed socio-economic survey

needs to be conducted to ascertain the actual number of families losing land

and homestead, as a result of acquisition of land for various projects features

including reservoir submergence as a part of the EIA study, based on which

suitable Resettlement & Rehabilitation Plan can be formulated.

Urbanization and industrialization

The commissioning of a hydro-electric project provides significant impetus to

economic development in the area being supplied with power. Likewise, in the

project area, commissioning of a hydro-electric project would lead to

mushrooming of various allied activities, providing employment to locals in the

area. There is a demand for improvement in infrastructure, which

subsequently leads to formation of urban centres. Thus, commissioning of the

project is expected to usher in industrialization and urbanization in the area.


9-26

9.4 SUMMARY OF IMPACTS AND EMP A summary of impacts and recommended management measures are

summarized in Table-9.7.

Table-9.7

Summary of Impacts and suggested management measures

S. No.

Parameters Impact Management Measures

1. Land Environment

Construction phase Operation phase

• Soil erosion due to the

extraction of

construction material

from various quarry

sites.

• Temporary acquisition

of land for siting of

construction equipment

& material, waste

material, etc.

• Acquisition of forest

land, reserve forest and

private land.

• Proper treatment of

quarry site, and such

sites be located over

non-forest land.

• Such sites be located

over non-forest land

away from human

settlements.

• Formulation of

Compensatory

afforestation &

Conservation Plan and

R&R plan, based on

the type of land being

acquired.


9-27

S. No.


2. Water quality


• Water pollution due to

disposal of sewage

from labour colonies.

• Disposal of sewage

from project colony.

• Provision of community

toilets and septic tanks

• Provision of adequate

sewage treatment

facilities

3. Terrestrial flora


• Cutting of trees for

meeting fuel wood

requirements by labour.

• Acquisition of forest

land.

• Provision of community

kitchen by the

contractors engaged in

project construction.

• Compensatory

afforestation as per the

Indian Forest

Conservation Act

(1980) and formulation

of Conservation Plan.

4. Terrestrial fauna

Construction phase

• Disturbance to wildlife

due to operation of

various construction

equipment.

• Increased surveillance,

in the form of check

posts at major

construction sites and

labour camps.


9-28

S. No.


Operation phase

• Disturbance to wildlife

due to increased

accessibility in the area.

• Location of various

project appurtenances,

including labour

camps, away from

areas serving habitats

to wildlife in the area.

• Increased surveillance

by developing check

posts at sensitive

locations.

5. Aquatic Ecology


• Marginal decrease in

aquatic productivity due

to increased turbidity

and lesser light

penetration.

• Adverse impacts due to

disposal of construction

waste.

• Increased potential for

pisci-culture in the

reservoir formed due to

the project.

• Marginal impact, hence

no specific

management

measures are

suggested.

• Disposal of

construction waste at

appropriate sites.

• Stocking of reservoirs

by Fisheries

Department.


9-29

S. No.


6. Noise Environment

Construction phase

• Increase in noise levels

due to operation of


equipment.

• Construction

equipment to be

provided with noise

control measures.

7. Air Environment

Construction phase

• Increase in air pollution

due to operation of


equipment including

crushers.

• Cyclones to be

provided in various

crushers.

8. Socio-economic Environment


• Increase in employment

potential.

• Acquisition of private

land and homestead

• Increased power

generation

• Greater employment

opportunities.

-

• Compensation as per

Resettlement &

Rehabilitation plan and

Area Development

Activities


9-30

9.5 CONCLUSIONS AND RECOMMENDATIONS

The project entails acquisition of forest and private land in various

settlements, both on the left and right bank sides. Detailed studies as a part

of EIA need to be conducted to ascertain the adverse impacts on terrestrial

flora & fauna, riverine fisheries, and other aspects of environment. The project

envisages acquisition of land and homestead from significant number of

families., which will be a key issue in environmental clearance.

The following aspects need to be studied in detail as a part of next phase of

environmental studies:

- Impacts due to acquisition of forest land.

- Impacts on wildlife, especially species categorized as Schedule-I

species as per Wildlife Protection Act (1972).

- Increased potential for fisheries in the reservoir as a result of

construction of dam.

- Proper stabilization of quarry sites

- Management of pollution from various sources from labour camps

- Resettlement and Rehabilitation plan for families losing private land

and homesteads in project affected villages.


10-1

CHAPTER -X INFRASTRUCTURE FACILITIES

10.1 GENERAL

The Wainganga H.E. Project is a Dam-toe power house development. The

dam is proposed to be located near the village Daungar Saungi at bed level of

El 196.0 m immediately downstream of the confluence of the Khobragarhi

Nadi flowing from the east and joining on the left bank. A gross storage of

5995.24 M cum is proposed to be created with the help of concrete gravity

dam with crest gates in the main river reach flanked by earthen dams in the

flanks. The dam is proposed to be constructed on the border of Gadchiroli and

Chandrapur districts where the Wainganga river forms the border between the

two districts. It is proposed to divert the water through intakes in the power

dam blocks on the right flank. A rated discharge of 595.82 cumec shall pass

through 5 nos. penstock of 5.0 m dia embedded in the body of the dam to

lead the discharges to the dam-toe power station immediately downstream.

The tailrace channel, 300 m long shall discharge the water back to the river.

The major infrastructure facilities needed for construction of this project are

described in the following paragraphs.

10.2 COMMUNICATIONS

10.1.1 The nearest rail head to the project area is located at Bramhapuri about 25

km upstream of project site. Bramhapuri is connected to Nagpur (about 130

km) via Umred-Nagbhir section. The project is also approachable by road by

the same route i.e. Nagpur-Umred-Nagbhir-Bramhapuri. Another approach

can be from Chandrapur (District headquarter) located about 150 km from

Nagpur and connected by National Highway/State Highway. The Wainganga


10-2

dam site is located at a village Daungar Saungi which is about 95 km from

Chandrapur via Kelzar-Mul-Gadchiroli-Purla by state highway and further 10

km by single lane ordinary road going upstream along the Wainganga river.

This ordinary single lane road shall have to be widened & strengthened above

HFL level as a new approach road to the project site as the present road

caters only to the villages located near the river bank.

10.2.2 Roads in the Project Area

Apart from constructing of a new ordinary road passing nearby the proposed

project site, a new access road is required to be built from the approach road

to the dam site (1 km) of the Wainganga H.E. project.

Other permanent roads of about 50 km which would be required to be

constructed include road from the approach road to the proposed Dam site,

project colony, and other Power House Complex requirements like road to

Power House Colony, Stores, Quarry sites, dumping yard, plant machinery,

ferrule workshop for penstock rolling, godown, spares yard, site offices, etc.

Construction of roads are also required from dam / power house site to the

quarry sites, plant and machinery workshops etc.

10.2.3 Railways

The nearest railway station is at Chandrapur on the broad gauge line.

Railway siding for unloading heavy machineries and equipment has to be

provided at Chandrapur.


10-3

10.3 CONSTRUCTION POWER

The demand for power for construction activities is estimated to be about 5

MW taking into account capacity of electric driven equipment and lighting

which have to work within the target time for consideration. The initial

requirement in the first two years could be about 2 MW and this subsequently

can be increased to 5 MW.

The power requirement can be met with by procuring the supply from

Maharashtra State Electricity Board or equivalent authority. For making the

power available at project site it is proposed to extend new transmission line

for about 10 km from Gadchiroli town with 33/11 kV sub-station.

In addition to tapping grid supply, it is also proposed to provide supplemental

power aggregating to 2 MW as a standby in cases of interruptions in grid

supply.

10.4 TELECOMMUNICATION

To ensure efficient execution at various sites, adequate and reliable

telecommunication network is necessary. An electronic private Automatic

Exchange with a capacity of about 50 lines is proposed.

A VHF system is also proposed to link project Head Quarters with clients

head-quarters. Suitable number of mobile phones / walky talkies are also

proposed.


10-4

10.5 PROJECT COLONIES / BUILDINGS

10.5.1 The main project colony is proposed near Gadchiroli town which is the

District headquarters also and which is connected with National Highway.

Facilities such as school, post office, police station, market, primary health

centre, fire fighting arrangement etc. exist at Gadchiroli District Headquarter

but canteen, recreation facilities have to be developed near the dam site.

Administrative building and 30 family quarters and a hostel are also proposed

to be built at the proposed site.

Two more small colonies for staff of dam site and for Power House are

proposed to be built alongwith other infrastructure facilities.

10.5.2 Contractor’s Colony and Labour Colony

Contractor’s colony and labour colony located at Dam site along with all

amenities are proposed to be located near the construction works of the

project.

10.6 WORKSHOPS STORES, FABRICATION YARDS AND MAGAZINES

Workshops for maintaining the plant and equipment used for construction,

stores for construction materials, hydro-mechanical and electro-mechanical

equipments etc. will be built and maintained by the contractor. However, a

small workshop is planned for repair and maintenance facilities of project

transport vehicles and minimum essential equipment will be built by the

client.


10-5

Areas for fabrication and storage yards for the hydro – mechanical equipment,

viz the various gates and hoists, penstocks etc. will have to be identified near

the work sites.

Explosive magazines for the works at dam site and rock quarries are to be

built.

10.7 WATER SUPPLY AND SANITATION

For drinking purposes in the colony areas, suitable water treatment plants for

treating water drawn from the Wainganga river will be installed. For

construction purposes, water directly pumped from the river and stored will be

used.

Suitable sanitation and sewerage treatment facilities under environmental

protection measures shall be made at all the project and labour colony areas.


11-1

CHAPTER – XI CONSTRUCTION PLANNING & SCHEDULE

11.1 INTRODUCTION

The Wainganga H.E. Project is located at an altitude of about EL 200.0 m in

Wainganga sub-basin of Godavari Basin. The climatic parameters vary

considerably within the basin. The climate of the sub-basin is characterized

by hot summers from March to May months. The rainy season is from June to

September and some post monsoon season rains are also experienced.

However, for construction purposes the working season could be considered

from October to June months. The river has floods during July to September

with peaks mostly occurring in August and September. A period of 24 months

has been provided for preparation of Detailed Project Report and statutory

clearances approvals. Thereafter 24 months’ have been provided for pre-

construction activities of field investigations, sub-surface exploration and

creating infrastructure facilities, construction power, land acquisition,

engineering design and drawings, tender engineering etc. The construction

phase includes all the pre construction activities. A construction period of 5

years has been considered for completion of the project. This is based on

location of the project and remoteness of the area. This could be further

optimised in the event of other proposed projects also being taken up

simultaneously on Wainganga river in the Maharashtra State.

11.2 PROJECT IN BRIEF

Wainganga H.E. Project is envisaged as storage scheme across the

Wainganga river. Gross Storage of about 5995.24 Mcum with live storage of

5155.0 M cum is proposed to be created by construction of a storage dam


11-2

with crest gates arrangements. The dam comprises of 1366 m long and 3648

m long Earthen dams on the left and right flanks respectively. A concrete

spillway 796 m long is proposed in the river reach. Besides 6 Nos. NOF

concrete Blocks and 5 Nos. Power Dam Blocks, each 20 m long, are

proposed in the flanks adjoining the Spillway blocks. A discharge of 595.82

cumec is proposed to be diverted through 5 Nos. penstock of 5.0 m dia to the

surface power house proposed immediately downstream of the dam on the

right bank. A tail race channel, 300 m long, discharges the water back to the

river.

11.3 MATERIAL SOURCES

The site visit to the project area was made by a Team including Engineers

and Geologist for identification of the site for the Storage Dam and

appurtenant works. The reconnaissance visit reveal that material required for

undertaking construction of various components of the project viz. earth dam,

concrete spillway, power house etc. are available in the vicinity of the area.

The sand is available in the nearby areas as well as in the river bed. The

coarse aggregate requirements can be met by crushing the rocks from the

nearby quarry sites.

11.4 CONTRACT PACKAGES

The contracts packages shall mainly consist of the following:

a) Spillway dam concrete works and earthen dams including diversion

works, coffer dams / dykes approaches, flood protection works, river

training works, etc.

b) Power dam blocks including Power house and tail race works

c) Hydro mechanical equipment

d) Hydro Electrical equipment


11-3

The eligibility of the contractors shall have to be suitably fixed based on

working experience under similar conditions. The auxiliary works of river

diversion, coffer dams, penstock fabrication and switchyard shall be part of

the civil works package. However, the work of providing basic site facilities

like storage sites for material, approach roads, minimal construction

equipment, testing laboratory, staff colony, water supply, field offices at power

house etc. could be taken up departmentally to enhance the pace of work of

the contractor and cost recovered from the contractor. The packages could

be contracted earlier so that by the time civil contractors mobilize, the site

facilities are made available.

11.5 SCHEDULE OF WORK

As envisaged the work shall be limited to 300 days in a year with 25 working

days in a month and 8 working hours per shift in a day. Two shift working is

proposed in the working season for expeditious completion of the project, third

shift could also be planned based on progress of work and constraints due to

remoteness of the site.

11.6 CONSTRUCTION ACTIVITIES

After the financial arrangements for construction of the project are decided,

Notice Inviting Tender for fixing the civil contractor can be invited within 6

months on ICB basis.

a) Diversion of river

As the river section at the dam storage site is fairly wide, coffer dams and ring

bunds completion is proposed in parts in different seasons before the actual

construction of the dam is taken up immediately after the execution of river


11-4

diversion works, during non-monsoon season and completed in first quarter

of following year before the river water starts rising. After the flood water in

the river recede, work on excavation of foundation and curtain grouting for

the embankment dam and foundation works in the river bed level completed

upto the planned level before the start of next flood season. The river bed

excavation shall be handled by 3.0 cum Hydraulic Excavator and Rear

Dumpers (25t).

b) The construction of the embankment dam and appurtenant works are

proposed to be completed by the end of 3rd year of the construction

programme. The spillway dam and power house civil works are proposed for

completion by the end of 4th year. The concreting shall be handled by 3 tower

cranes of 3 ton capacity of 50 m radius, 250 cum/hr batching and mixing plant

and 500 TPH aggregate processing plant.

c) Power House

The surface power house accommodates 5 units of 21 MW each (105 MW).

The excavation of the power house foundation is proposed to be undertaken

by the conventional method, jack hammers and mucking operations shall be

accomplished through trucks. Approach to the power house shall be from the

highway on the left bank..

A period of 27 months has been kept for power house excavation and

concreting. For concreting two batching and mixing plant of 300 cum/hr

capacity shall be installed at Dam and Power House site.

Transportation of concrete shall be carried by 5.0 cum transit mixer trollys.

The construction schedule at PFR stage studies is given in the enclosed Plate

11-1.


12-1

CHAPTER-XII

COST ESTIMATE

12.1 INTRODUCTION

Wainganga H.E. Project is envisaged as storage scheme across the

Wainganga river. Gross Storage of about 5995.24 M cum with live storage of

5155.0 M cum is proposed to be created by construction of a storage dam

with crest gates arrangements. The dam comprises of 1366 m long and 3648

m long Earthen dams on the left and right flanks respectively. A concrete

spillway 796 m long is proposed in the river reach. Besides 6 Nos. NOF

concrete Blocks and 5 Nos. Power Dam Blocks, each 20 m long, are

proposed in the flanks adjoining the Spillway blocks. A discharge of 595.82

cumec is proposed to be diverted through 5 Nos. penstock of 5.0 m dia to the

surface power house proposed immediately downstream of the dam on the

right bank. A tail race channel, 300 m long, discharges the water back to the

river.

12.2 The Project is estimated to cost Rs.1115.61 crore at June 2003 price level

the break down of cost is given below :

Item Estimated Cost ( Rs.Crore )

Civil Works 936.91

Electrical Works 178.70

Sub Total (Generation) 1115.61


12-2

The project estimate has been prepared on the basis of “Guidelines for

preparation of cost estimates for River Valley projects” published by Central

Water Commission, New Delhi. The abstract of cost is enclosed as

Annexure 12.1. The cost of various Electro-Mechanical works are placed at

Annexure 12.2. The above cost does not include the cost of transmission

line from the project to Chandrapur sub-station which is estimated as Rs.

29.75 crores.

The estimate for civil & Hydro mechanical works have been prepared based

on the as average rates for major items of works made available by CWC in

the “guidelines for estimating the civil cost for the preparation of PFR”.

The electro mechanical rates have been adopted on the basis of enquiry

floated to various reputed manufactures / supplier. The rates are inclusive of

excise duty & taxes.

The phased programme of construction has been given in the relevant

chapter with this report.

Cost provisions for the various items mentioned below has been made on

lump sum percentage basis of C-Works & J – Power Plant Civil Works for

working out the total cost of project at pre - feasibility stage.


12-3

S. No.

Items Provisions of % of C- Works & J - Power Plant Civil Works

1 A. Preliminary 2%

2 K. Buildings 4%

3 O. Miscellaneous 4%

4 P. Maintenance 1% of C+J+K+R

5 R. Communication 4%

6 X. Environment & Ecology 2%

7 Y. Losses on Stock 0.25% of C – Works, J - Power

Plant - Civil Works, K - Building & R -

Communication

Sl.NO. ITEM Qty. Unit Rate Unit Amount (In Rs. Lakhs)

Total Amount (In Rs. Lakhs)

Rate Amount (In Rs. Lakhs)

1 2 3 4 5 6 7 8 9 10

1 Generating Unit and Bus Duct 40 MW, 93.75 RPM, 21.03 M Head

4 Nos. 0.089 Rs./kW 14240 16% 2278.4 16518.40

2 Step up transformer 11/220 kV,46 MVA, Three Phase 4 Nos. 200 Rs./kVA 368 16% 58.88 426.883 Auxiliaries Electrical Equipment for power Stations (

5% of item 1)712 16% 113.92 825.92

4 Auxiliary Equipment and services for power stations (5% ofitem 1)

712 16% 113.92 825.92

5 Conventional Switchyard -220 kV 8 bays 120 Rs. Lakhs/bay 960 16% 153.6 1113.606 Spares( 5% of 1 and 3% of 2-5) 794.56 794.567 Sub- total(1) 17786.56 2718.72 20505.288 Central Sales Tax @ 4% of item 7 820.219 Transportation & Insurance @ 6% of item 7 1230.32

10 Erection and Commissioning @ 8% of item 7 Except Spares

1576.86

11 Sub- total(2) 24132.6712 Establishment, Contingency, other Charges @ 11% of item

7 excluding duties1956.52

GRAND TOTAL 26089.19

Excise Duty

SCHEME NAME - WAINGANGACOST ESTIMATE OF ELECTRO-MECHANICAL WORKS FOR PRE - FEASIBILTY REPORT

Annexure-12.2


13-1

CHAPTER – XIII ECONOMIC EVALUATION

13.1 GENERAL

The economic and financial evaluation of the WAINGANGA H.E project have

been considered as per the standard guidelines issued by Central Electricity

Authority and the norms laid down by the Central Electricity Regulatory

Commission (CERC) for Hydro projects have been kept in view in this regard.

13.2 PROJECT BENEFITS

The scheme would afford on annual average energy generation of 246.146

GWh . The project would provide 105 MW of peaking capacity benefits.

13.3 TOTAL COST

The project cost (Civil and E& M ) has been estimated at Rs.1115.61 crores

without IDC based on the criteria for “Adoption of Rates and Cost for

preparation of PFRs of hydro-electric projects” issued by CEA and is as given

below :

1. Cost of civil works = Rs. 936.91 Crores

2. Cost of Electrical/Mechanical works = Rs. 178.7 Crores

Total = Rs.1115.61 Crores


13-2

13.4 MODE OF FINANCING

The project is proposed to be financed with a debt equity ratio of 70:30. An

interest rate of 10% on the loan component has been considered for the

financial analysis of the project. The interest on the working capital is taken

as 9.75%.

13.5 Phasing of Expenditure The project is proposed to be completed in 5 years period in all respect with

full benefit available after 5 years. The detailed year wise phasing of

expenditure based upon the above construction programme for Civil &

Electrical works is given in Annexure 13.1.

13.6 FINANCIAL ANALYSIS 13.6.1 Basic And Normative Parameters

The following basic parameters have been adopted for working out the

financial analysis of the project.

i) Estimated capital cost of Rs. 1292.02 Crores considering the Interest

during construction.

ii) Average annual energy generation of 246.146 GWh. has been

estimated.

iii) Operation & maintenance expenses (including insurance) @ 1.5% of

the project cost in the first year with 5% escalation every year.

iv) Depreciation @ 3.5 % has been considered on an average basis.

v) Auxiliary consumption @ 0.5 % of the energy generated.

vi) Transformation loss @ 0.5% of the energy generated.


13-3

vii) Interest on working capital @ 9.75%.

viii) Interest during construction has been worked out based upon the

interest rates as mentioned above. The computations are given in

Annexure 13.2 for present day capital cost.

ix) Corporate tax @ 30%.

x) Return on equity @ 14%.

13.6.2 Assessment of Tariff

Based upon the parameters given above, the sale rate of energy at bus bar

has been computed in Annexure 13.3. The sale rate applicable in the first

year and levellised tariff is indicated below.

TABLE – 13.2

Tariff Period

Tariff (Rs./KWh)

First Year

Levellised Tariff

3.86

3.32

13.7 CONCLUSION

The sale rate of energy indicated above shows that the energy generated

from the project is on the higher side . The levelised cost can be further

reduced on the bsis of further optimization of the FRL and period of

construction.

Parameters Values

Project Cost (Rs in crores)

Civil 936.91Electrical 178.70Total Cost 1115.61Construction Period ( in years) 5

Debt 70.00%Equity 30.00%Phasing of Expenditure

1st year 10.00%2nd year 30.00%3rd year 30.00%4th year 20.00%5th year 10.00%

Interest on Working capital 9.75%Life of Hydro electric Project 35

Depreciation (as per ES Act ) 3.50%

Interest on loan 10%Aux. ConsumptionSurface Hydro Station 0.50%(Static Excitation) (% of energy generated)Transformation Losses 0.50%

O& M 1.50%O& M escalation 5.00%Depreciation (IT ACT) 25.00%Income Tax 30.00%Capacity ( MW) 160Annual Energy ( GWh) 557.07Design Energy (GWh) 545.36Discount Rate (%) 12Levellised Tarrif 3.32Annual Tarriff 3.86

WAINGANGA HYDEL SCHEME ( Surface Power House )

Annexure 13.2

Debt : Equity 70 : 30Interest rate @ 10 %

(INR crores)

Year Project Equity Loancost component component Cummulative IDC Equity for Loan for TOTAL Capitalised

(30%) (70%) loan 10.0% IDC IDC IDC IDC cost(6) x 0.30 (6) x 0.70 10.0%

1 2 3 4 5 6 7 8 9 10 11

1 111.56 111.56 0.00 0.00 0.00 0.00 0.00 0.00 0.00 111.562 334.68 223.12 111.56 111.56 5.58 1.67 3.90 0.20 5.77 340.463 334.68 0.00 334.68 446.24 27.89 8.37 19.52 1.37 29.26 363.944 223.12 0.00 223.12 669.37 55.78 16.73 39.05 4.30 60.08 283.205 111.56 0.00 111.56 780.93 72.51 21.75 50.76 8.79 81.30 192.86

Total 1115.61 334.68 780.93 161.76 48.53 113.23 14.64 176.41 1292.02

ITERATION - I GRAND TOTAL

(Civil & E&M)


Calculation of Interest During Construction

INR crores

Year Civil cost E & M cost Total cost

1 93.69 17.87 111.562 281.07 53.61 334.683 281.07 53.61 334.684 187.38 35.74 223.125 93.69 17.87 111.56

Total 936.91 178.70 1115.61

Annexure -13.1


Phasing of Expenditure

Annexure - 13.3WAINGANGA HYDEL SCHEME ( Surface Power House )

Debt:Equity Ratio 7.0 : 3.0

Yr 1 Yr 2 Yr 3 Yr 4 Yr 5 Yr 6 Yr 7 Yr 8 Yr 9 Yr 10 Yr 11 Yr 12

BASIC PARAMETERS Capacity (MW) 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00Capital Cost (INR crores) 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61Capital Cost with IDC . 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02Equity Portion (%) 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00Debt Portion (%) 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00Capital Cost/MW (INR crores) 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08Interest rate for WC (%) 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75Tax rate (%) 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00Interest rate on loan from Financial Institutions (%) 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00Total annual energy (GWh) 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07Design energy with 90% dependibility (GWh) 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36Saleable Energy after aux. (GWh) 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92consumption & transformation losses

FINANCIAL PACKAGE (INR crores)

LOAN % of % of Intt. AMOUNT EQUITY % of % of AMOUNTLoan Component 904.4 total project Rate (INR total project (INR

loan cost (%) crores) equity cost crores) Fin. Institutions 904.41

Equity component 387.60 Fin. Institutions 100.00 70.00 10.00 904.41 Equity 100.00 30.00 387.60

387.60 1292.0

Total 100.00 70.00 904.41 Total 100.00 30.00 387.60Period Repayment Moratorium Installment/yr.

Financial Inst. 10 0 1

Repayment Amount/year Financial Institutions 90.44

Construction Period (Yrs.) 5

TARIFF CALCULATIONS WITH PROJECTED COMPLETION COST

1/12





NORMATIVE PARAMETERS Year 1 2 3 4 5 6 7 8 9 10 11 12O & M Charges incl. Insurance (%) 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50O & M Inflation rate (%) 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00Rate of return on equity (%) 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00Rate of Depreciation (ES Act) (%) 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50Rate of Depreciation (IT Act) (%) 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00Spares for 1 yr -1/5th C.S 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58Auxiliary consumption (%) 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50Transformation Losses (%) 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50

SCHEDULE OF LOAN REPAYMENTAGENCY Year 1 2 3 4 5 6 7 8 9 10 11 12

FINANCIAL INSTITUTIONSOutstanding Term loan 904.41 813.97 723.53 633.09 542.65 452.21 361.76 271.32 180.88 90.44 0.00 0.00Term loan installment 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 0.00 0.00Cum. Loan Repaid 90.44 180.88 271.32 361.76 452.21 542.65 633.09 723.53 813.97 904.41 904.41 904.41Interest on Term loan 85.92 76.87 67.83 58.79 49.74 40.70 31.65 22.61 13.57 4.52 0.00 0.00Total Yearly installment 176.36 167.32 158.27 149.23 140.18 131.14 122.10 113.05 104.01 94.96 0.00 0.00

LOAN SERVICINGOutstanding Term loan 904.41 813.97 723.53 633.09 542.65 452.21 361.76 271.32 180.88 90.44 0.00 0.00Loan Repayment Installment 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 0.00 0.00Sources of Funds for Repayment - Depreciation (ES Act) 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 0.00 0.00 - Advance Depreciation 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 - Additional sources (ROE ) 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 0.00 0.00

COMPUTATION OF TARIFF COMPONENTS

INTEREST ON CAPITALInterest on Term loan 85.92 76.87 67.83 58.79 49.74 40.70 31.65 22.61 13.57 4.52 0.00 0.00Total Yearly Installment 176.36 167.32 158.27 149.23 140.18 131.14 122.10 113.05 104.01 94.96 0.00 0.00

2/12





RATE OF RETURNEquity amount 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60Return on Equity 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26

O & M EXPENSES 19.38 20.35 21.37 22.44 23.56 24.73 25.97 27.27 28.63 30.07 31.57 33.15

INTEREST ON WORKING CAPITAL

WORKING CAPITALO & M Expenses - 1 month 1.62 1.70 1.78 1.87 1.96 2.06 2.16 2.27 2.39 2.51 2.63 2.76Spares 1 year - 1/5th cap spares 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58Receivables for 2 months

DEP(ES Act) 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 Interest 14.32 12.81 11.31 9.80 8.29 6.78 5.28 3.77 2.26 0.75 0.00 0.00 Return on Equity 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 O&M 3.23 3.39 3.56 3.74 3.93 4.12 4.33 4.54 4.77 5.01 5.26 5.52 I.Tax 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.33 Interest on W.C. 0.47 0.45 0.44 0.42 0.41 0.39 0.38 0.36 0.35 0.33 0.33 0.36

Total Working capital 38.80 37.52 36.25 34.99 33.75 32.52 31.31 30.11 28.93 27.77 27.39 30.14Interest on Working Capital 3.78 3.66 3.53 3.41 3.29 3.17 3.05 2.94 2.82 2.71 2.67 2.94

DEPRECIATION (ES ACT) (INR crores)Total Depreciable Amount 1162.81 1117.59 1072.37 1027.15 981.93 936.71 891.49 846.27 801.05 755.83 710.61 665.39Opening Depreciation Fund 0.00 -45.22 -90.44 -135.66 -180.88 -226.10 -226.10 -226.10 -226.10 -226.10 -226.10 -180.88Yearly Depreciation (ES Act) 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22Cumulative Depreciation Fund 45.22 0.00 -45.22 -90.44 -135.66 -180.88 -180.88 -180.88 -180.88 -180.88 -180.88 -135.66Loan Repayment Installment 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 90.44 0.00 0.00Advance Dep. for loan Repayment 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Return on Eq. for loan Repayment 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 0.00 0.00Closing Cummulative Dep. Fund -45.22 -90.44 -135.66 -180.88 -226.10 -226.10 -226.10 -226.10 -226.10 -226.10 -180.88 -135.66Total Depreciation 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22Net Depreciable Amount 1162.81 1117.59 1072.37 1027.15 981.93 936.71 891.49 846.27 801.05 755.83 710.61 665.39

DEPRECIATION (IT ACT) (INR crores)Sum at charge 1292.02 969.01 726.76 545.07 408.80 306.60 229.95 172.46 129.35 97.01 72.76 54.57Depreciation (IT Act) 323.00 242.25 181.69 136.27 102.20 76.65 57.49 43.12 32.34 24.25 18.19 13.64Dep.limited to 90% of capital cost 323.00 242.25 181.69 136.27 102.20 76.65 57.49 43.12 0.15 0.00 0.00 0.00

3/12





TAX LIABILITY (INR crores) Yearly Profit/loss -223.52 -142.77 -82.20 -36.78 -2.72 22.83 42.00 56.37 99.34 99.49 99.49 99.49Cummulative Profit/loss (+/-) -223.52 -366.29 -448.49 -485.27 -487.99 -465.15 -423.16 -366.79 -267.45 -167.96 -68.48 31.01Tax liability 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 13.95

CAPACITY AND ENERGY CHARGES Annual Capacity Charge (INR crores) 131.14 122.10 113.05 104.01 94.96 85.92 76.87 67.83 58.79 49.74 45.22 45.22

Annual Energy Charge (INR crores) 77.43 78.27 79.17 80.11 81.11 82.17 83.29 84.47 85.72 87.04 88.50 104.30

Total Annual Charge (INR crores) 208.57 200.37 192.22 184.12 176.08 168.09 160.16 152.30 144.51 136.78 133.72 149.52Average Tariff (INR/kWh) 3.86 3.71 3.56 3.41 3.26 3.11 2.97 2.82 2.68 2.53 2.48 2.77Average Tariff for 5 years (INR/kWh) 3.56 2.82 3.10

Discount rate (%) 12.00 / Year 1 2 3 4 5 6 7 8 9 10 11 12Discounted Average Tariff (INR/kWh) 3.86 3.31 2.84 2.43 2.07 1.77 1.50 1.28 1.08 0.91 0.80 0.80Levellised Eq.Avg. Tariff (INR/kWh) 3.32

4/12

BASIC PARAMETERS Capacity (MW) Capital Cost (INR crores) Capital Cost with IDC .Equity Portion (%)Debt Portion (%)Capital Cost/MW (INR crores)Interest rate for WC (%)Tax rate (%)Interest rate on loan from Financial Institutions (%)Total annual energy (GWh)Design energy with 90% dependibility (GWh)Saleable Energy after aux. (GWh)consumption & transformation losses


Loan Component 904.4

Fin. Institutions 904.41

Equity component 387.60387.60 1292.0

Period Repayment Moratorium Installment/yr.


Repayment Amount/yearFinancial Institutions 90.44


Annexure - 13.3



160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.001115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.611292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02

30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.0070.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.008.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.089.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75

30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.0010.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00

557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92

WAINGANGA HYDEL SCHEME ( Surface Power House ) TARIFF CALCULATIONS WITH PROJECTED COMPLETION COST

5/12

NORMATIVE PARAMETERS YearO & M Charges incl. Insurance (%)O & M Inflation rate (%)Rate of return on equity (%)Rate of Depreciation (ES Act) (%)Rate of Depreciation (IT Act) (%)Spares for 1 yr -1/5th C.SAuxiliary consumption (%)Transformation Losses (%)

SCHEDULE OF LOAN REPAYMENTAGENCY Year

FINANCIAL INSTITUTIONSOutstanding Term loanTerm loan installmentCum. Loan RepaidInterest on Term loanTotal Yearly installment

LOAN SERVICINGOutstanding Term loanLoan Repayment InstallmentSources of Funds for Repayment - Depreciation (ES Act) - Advance Depreciation - Additional sources (ROE )


INTEREST ON CAPITALInterest on Term loanTotal Yearly Installment

Annexure - 13.3




13 14 15 16 17 18 19 20 21 22 23 241.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.505.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00

14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.003.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50

25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.002.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.580.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.500.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50

13 14 15 16 17 18 19 20 21 22 23 24

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.410.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6/12

RATE OF RETURNEquity amount Return on Equity

O & M EXPENSES


WORKING CAPITALO & M Expenses - 1 monthSpares 1 year - 1/5th cap sparesReceivables for 2 months

DEP(ES Act) Interest Return on Equity O&M I.Tax Interest on W.C.

Total Working capital Interest on Working Capital

DEPRECIATION (ES ACT) (INR crores)Total Depreciable AmountOpening Depreciation FundYearly Depreciation (ES Act)Cumulative Depreciation FundLoan Repayment InstallmentAdvance Dep. for loan RepaymentReturn on Eq. for loan RepaymentClosing Cummulative Dep. FundTotal Depreciation Net Depreciable Amount

DEPRECIATION (IT ACT) (INR crores)Sum at chargeDepreciation (IT Act)Dep.limited to 90% of capital cost

Annexure - 13.3




387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.6054.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26

34.80 36.54 38.37 40.29 42.30 44.42 46.64 48.97 51.42 53.99 56.69 59.53

2.90 3.05 3.20 3.36 3.53 3.70 3.89 4.08 4.29 4.50 4.72 4.962.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58

7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.54 7.540.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.009.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.045.80 6.09 6.40 6.72 7.05 7.40 7.77 8.16 8.57 9.00 9.45 9.927.46 7.46 7.46 7.46 7.46 7.46 7.46 7.46 7.46 7.46 7.46 7.460.43 0.44 0.44 0.45 0.45 0.46 0.47 0.47 0.48 0.49 0.50 0.51

35.76 36.20 36.66 37.15 37.66 38.19 38.75 39.34 39.96 40.61 41.30 42.013.49 3.53 3.57 3.62 3.67 3.72 3.78 3.84 3.90 3.96 4.03 4.10

620.17 574.95 529.73 484.51 439.29 394.06 348.84 303.62 258.40 213.18 167.96 122.74-135.66 -90.44 -45.22 0.00 45.22 90.44 135.66 180.88 226.10 271.32 316.54 361.76

45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22-90.44 -45.22 0.00 45.22 90.44 135.66 180.88 226.10 271.32 316.54 361.76 406.98

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

-90.44 -45.22 0.00 45.22 90.44 135.66 180.88 226.10 271.32 316.54 361.76 406.9845.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22

620.17 574.95 529.73 484.51 439.29 394.06 348.84 303.62 258.40 213.18 167.96 122.74

40.93 30.69 23.02 17.27 12.95 9.71 7.28 5.46 4.10 3.07 2.30 1.7310.23 7.67 5.76 4.32 3.24 2.43 1.82 1.37 1.02 0.77 0.58 0.430.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7/12

TAX LIABILITY (INR crores)Yearly Profit/lossCummulative Profit/loss (+/-)Tax liability

CAPACITY AND ENERGY CHARGES Annual Capacity Charge (INR crores)

Annual Energy Charge (INR crores)

Total Annual Charge (INR crores)Average Tariff (INR/kWh)Average Tariff for 5 years (INR/kWh)

Discount rate (%) 12.00 / YearDiscounted Average Tariff (INR/kWh)Levellised Eq.Avg. Tariff (INR/kWh)

Annexure - 13.3




99.49 99.49 99.49 99.49 99.49 99.49 99.49 99.49 99.49 99.49 99.49 99.49130.49 229.98 329.46 428.95 528.43 627.92 727.40 826.89 926.38 1025.86 1125.35 1224.8344.77 44.77 44.77 44.77 44.77 44.77 44.77 44.77 44.77 44.77 44.77 44.77

45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22 45.22

137.32 139.11 140.98 142.94 145.01 147.18 149.45 151.84 154.35 156.99 159.75 162.66

182.54 184.33 186.20 188.17 190.23 192.40 194.67 197.06 199.57 202.21 204.97 207.883.38 3.41 3.45 3.49 3.52 3.56 3.61 3.65 3.70 3.75 3.80 3.85

3.57 3.80

13 14 15 16 17 18 19 20 21 22 23 240.87 0.78 0.71 0.64 0.57 0.52 0.47 0.42 0.38 0.35 0.31 0.28

8/12

BASIC PARAMETERS Capacity (MW) Capital Cost (INR crores) Capital Cost with IDC .Equity Portion (%)Debt Portion (%)Capital Cost/MW (INR crores)Interest rate for WC (%)Tax rate (%)Interest rate on loan from Financial Institutions (%)Total annual energy (GWh)Design energy with 90% dependibility (GWh)Saleable Energy after aux. (GWh)consumption & transformation losses


Loan Component 904.4

Fin. Institutions 904.41

Equity component 387.60387.60 1292.0

Period Repayment Moratorium Installment/yr.


Repayment Amount/yearFinancial Institutions 90.44


Annexure - 13.3

7.0 : 3.0

Yr 25 Yr 26 Yr 27 Yr 28 Yr 29 Yr 30 Yr 31 Yr 32 Yr 33 Yr 34 Yr 35

160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.00 160.001115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.61 1115.611292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02 1292.02

30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.0070.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.00 70.008.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.08 8.089.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75 9.75

30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.00 30.0010.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00

557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07 557.07545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36 545.36539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92 539.92

9/12

NORMATIVE PARAMETERS YearO & M Charges incl. Insurance (%)O & M Inflation rate (%)Rate of return on equity (%)Rate of Depreciation (ES Act) (%)Rate of Depreciation (IT Act) (%)Spares for 1 yr -1/5th C.SAuxiliary consumption (%)Transformation Losses (%)

SCHEDULE OF LOAN REPAYMENTAGENCY Year

FINANCIAL INSTITUTIONSOutstanding Term loanTerm loan installmentCum. Loan RepaidInterest on Term loanTotal Yearly installment

LOAN SERVICINGOutstanding Term loanLoan Repayment InstallmentSources of Funds for Repayment - Depreciation (ES Act) - Advance Depreciation - Additional sources (ROE )


INTEREST ON CAPITALInterest on Term loanTotal Yearly Installment

Annexure - 13.3

7.0 : 3.0


25 26 27 28 29 30 31 32 33 34 351.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.50 1.505.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00

14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.00 14.003.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50 3.50

25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.00 25.002.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.580.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.500.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50 0.50

25 26 27 28 29 30 31 32 33 34 35

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.41 904.410.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

10/12

RATE OF RETURNEquity amount Return on Equity

O & M EXPENSES


WORKING CAPITALO & M Expenses - 1 monthSpares 1 year - 1/5th cap sparesReceivables for 2 months

DEP(ES Act) Interest Return on Equity O&M I.Tax Interest on W.C.

Total Working capital Interest on Working Capital

DEPRECIATION (ES ACT) (INR crores)Total Depreciable AmountOpening Depreciation FundYearly Depreciation (ES Act)Cumulative Depreciation FundLoan Repayment InstallmentAdvance Dep. for loan RepaymentReturn on Eq. for loan RepaymentClosing Cummulative Dep. FundTotal Depreciation Net Depreciable Amount

DEPRECIATION (IT ACT) (INR crores)Sum at chargeDepreciation (IT Act)Dep.limited to 90% of capital cost

Annexure - 13.3

7.0 : 3.0


387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.60 387.6054.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26

62.50 65.63 68.91 72.36 75.97 79.77 83.76 87.95 92.35 96.96 101.81

5.21 5.47 5.74 6.03 6.33 6.65 6.98 7.33 7.70 8.08 8.482.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58 2.58

7.54 5.38 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.009.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04 9.04

10.42 10.94 11.48 12.06 12.66 13.30 13.96 14.66 15.39 16.16 16.977.46 6.49 4.07 4.07 4.07 4.07 4.07 4.07 4.07 4.07 4.070.51 0.49 0.40 0.41 0.42 0.43 0.45 0.46 0.47 0.49 0.50

42.77 40.40 33.33 34.20 35.11 36.08 37.08 38.14 39.26 40.43 41.654.17 3.94 3.25 3.33 3.42 3.52 3.62 3.72 3.83 3.94 4.06

77.52 32.30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00406.98 452.21 484.51 484.51 484.51 484.51 484.51 484.51 484.51 484.51 484.5145.22 32.30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

452.21 484.51 484.51 484.51 484.51 484.51 484.51 484.51 484.51 484.51 484.510.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

452.21 484.51 484.51 484.51 484.51 484.51 484.51 484.51 484.51 484.51 484.5145.22 32.30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.0077.52 32.30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

1.30 0.97 0.73 0.55 0.41 0.31 0.23 0.17 0.13 0.10 0.070.32 0.24 0.18 0.14 0.10 0.08 0.06 0.04 0.03 0.02 0.020.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

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TAX LIABILITY (INR crores)Yearly Profit/lossCummulative Profit/loss (+/-)Tax liability

CAPACITY AND ENERGY CHARGES Annual Capacity Charge (INR crores)

Annual Energy Charge (INR crores)

Total Annual Charge (INR crores)Average Tariff (INR/kWh)Average Tariff for 5 years (INR/kWh)

Discount rate (%) 12.00 / YearDiscounted Average Tariff (INR/kWh)Levellised Eq.Avg. Tariff (INR/kWh)

Annexure - 13.3

7.0 : 3.0


99.49 86.57 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.26 54.261324.32 1410.88 1465.15 1519.41 1573.68 1627.94 1682.20 1736.47 1790.73 1845.00 1899.26

44.77 38.95 24.42 24.42 24.42 24.42 24.42 24.42 24.42 24.42 24.42

45.22 32.30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

165.71 162.79 150.84 154.37 158.08 161.97 166.06 170.35 174.86 179.59 184.56

210.93 195.09 150.84 154.37 158.08 161.97 166.06 170.35 174.86 179.59 184.563.91 3.61 2.79 2.86 2.93 3.00 3.08 3.16 3.24 3.33 3.42

3.04 3.24

25 26 27 28 29 30 31 32 33 34 350.26 0.21 0.15 0.13 0.12 0.11 0.10 0.09 0.09 0.08 0.07

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Wainganga Report (Previous Project)

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