CHAPTER - 4

HYDROGEOLOGY OF UPPER TUNGA PROJECT

V_^(««M5^ —T riuf4 /^ \M44n<Mti4J\<MU/U*y l^JM^S/l/ K^I^^UMI/ cT'JAJMX^

4. Tunga River

Tunga river is tributary of mighty river Krishna bom in Western ghats

on a hill known as Varaha Parvatha at a place called Gangamula. From here,

the river flows through two dustricts in Kamataka, Chikmagalur and Shimoga

district. The river has a length of 147 km from its origin and merges with

Bhadra river at Kudli, a small town near Shimoga city in Kamataka. The river

is given the compound name Tungabhadra from this point onwards. The

Tungabhadra flows eastwards and merges with Krishna River in Andhra

Pradesh. The river is famous for the sweetness of its water. It has a dam built

across it at Gajanur and a larger dam has been built across the compound

Tungabhadra river at Hospet, in Bellary district.

RIVER PROFILE AT UTP

25

^ 20 UJ

? 15

g 10

" 1 I I I 1 I " I 1 I M I I I I I I I r M I 1 I I 11 I I I I 11 I

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79

CHAINAGE

Fig. 5. Profile of Upper Tunga Project

42

^^Aapt&i/ -4 '^}ti^dm/}eoio^ ap'~lippe/t' %un^ ^lojecl

4.1 River and River Resources of Karnataka

Kamataka is blessed with water wealth in its numerous rivers and

streams and to a limited extent in its ground water. The development of water

resources forms the very backbone of economic prosperity of the State,

especially at rural areas. Protected water supply for drinking, irrigation and

generation of hydroelectric power are vital activities relating to such

development.

Table 10. Karnataka's river and their Length in Karnataka and its

neighbour States

SI. No.

Name of River/Tributaries Karnataka

Neighbour State

Total Length km

1 Aghinashini 121 - 121

2 Bedti 161 - 161

3 Bhima 290 83 373

4 Ghataprabha 216 8 24

5 Hemavathi 245 - 245

6 Kabini 230 - 230

7 Kali 184 - 184

8 Kaveri/Cauvery 320 64 384

9 Krishna 483 42 525

10 Malaprabha 304 - 304

11 Munjra 116 39 155

12 Netravathi 96 - 96

13 Palar 93 - 93

14 Pinakini-North 61 - 61

15 Pinakini-South 70 - 70

16 Sharavathi 128 - 128

17 Tungabhadra 381 58 439

18 Vedavathi 293 26 319

43

'"^/tapte^ -4 '^-Kijd/voi^e^iio^ of iXpfi&f ^unqa/ '^tofecl'

KARNATAKA: RIVER'S LENGTH IN STATE & NEIGHBOUR STATE

INDEX: SERIES -1-BLUE-FLOW IN K/V?NATAKA SERIES-2-RED-FLOW IN NEIGHBOUR STATE

SERIES-3-YELLOW-TOTAL FLOW LENGTH

RIVER{S)

VEDAVATHt

TUNGABHADRA

SHARAVATHI

PiNAKINI-SOUTH

PINAKINI-NORTH

PALAR

NETRAVATHI

MUNJRA

MALAPRABHA

WIISHNA

KALI

KABINI

HEMAVATHI

GHATAPRABHA

CAUVERY

BHIMA

BEDTHl

AGHINASHINI

DSeri9s3

•S«1es2

BSeriesI

100 2CX) 300 400 500

RIVER FLOW LEN6TH{KM)

600

Fig. 6. River length in state and neighouring states

44

'^^^Aapte/i/ -4 '^{ifd/iofealof^op^^Upfze^ %un^ ^lofecl

4.2. Krishna River Basins

The Upper Tunga Project has been constructed across Tunga River,

which is a major tributary to the mighty river Krishna. The details of Krishna

basin are given below.

SI. No

Name of Basin

Catchment area in sq.lim.

Percentage of Total area of the State

Estimated average flow in Mcum

1 Krishna 1,13,271 59.06 27,500

Table 11. Percentage area of Districts Lying in Different River Basins

SI. No. District Krish

na Cauve

ry West

flowing South

Pennar North

Pennar Palar Goda vari Total

1 Bagalkot 2 Bangalore - 67.3 - 25.1 6.6 1.0 - 100 3 Bangalore

Rural 4 Belgaum 90.8 - 9.2 - - - • 100 5 Bellary 100 - - - - - - 100 6 Bidar 17.9 - - - ~ 82.1 100 7 Bijapur 100 - - - - - - 100 8 Chamaraja-

nagar 9 Chikmagalur 86.0 8.4 5.6 • - - . 100 10 Chitradurga 100 - - - ~ - 100 11 Dakshina

Kannada - - 100 - - - - 100

12 Davangere 13 Dharwad 86.5 - 13.5 - - - - 100 14 Gadag 15 Gulbarga 100 - • - ~ - 100 16 Hassan 19.3 73.5 7.2 - - - - 100 17 Haven 18 Kodagu - 63.4 36.6 - - - - 100 19 Kolar - - - 21.2 47.4 31.4 - 100 20 Koppal 21 Mandya - 100 - - - - - 100 22 Mysore - 100 - - - - - 100 23 Raichur 100 - - - - - - 100 24 Shimoga 74.4 - 25.6 - - - - 100 25 Tumkur 37.1 35.4 - - 27.5 - - 100 26 Udupi 27 Uttara

Kannada 6.2 - 93.8 - - - - 100

45

''^^Aapt&i' -^ '^{t^<kofeolo^op^^Upfze^ %Mt^ ^lofecl

Table 12. Percentage of Krishna river basin in each district s of Karnataka

SI.

No. District

Percentage of Krishna River

basin distribution

SI.

No. District

Percentage of Krishna River

basin distribution

1 Bagalkote - 15 Gulberga 100

2 Bangalore - 16 Hassan 19.3

3 Bangalore

Rural

17 Haveri

4 Belgaum 90.8 18 Kodagu -

5 Bellary 100 19 Kolar -

6 Bidar 17.9 20 Koppal

7 Bijapur 100 21 Mandya -

8 Chamaraja

Nagar

22 Mysore "

9 Chikmagalur 86.0 23 Raichur 100

10 Chitradurga 100 24 Shimoga 74.4

11 Dakshina

Kannada

- 25 Tumkur 37.1

12 Davangere 26 Udupi

13 Dharwad 86.5 27 Uttara

Kannada

6.2

14 Gadag -

46

'~Ehafit&i' -4 ''^O^dto^eolofi^ op'~llpfie4/ %iutfa/ '^tofecl

Table 13. List of Rivers and Streams in Tungabhadra Sub Basin in

Karnataka

Tungabhadra Sub-basin

Tunga Malatihole Sitamma

Hyhole Kushinala Kalahatti hole

Tolehalla Somavahini hole Hebbe

Jambadahalla Haridra Satyagali halla

Vadagattihalla Harihalla Ramappavanka

Garachivanka Maskinala Tungabhadra

Hadagana halla Kanakanala Sindhoor nadi

Hirenala Hirehalla Doddahalla

Dandavati Bhadra Munduwad nala

Varada Dharma Mavinahole

Kumudwati Salurhalla Kallu oddu halla

Naimuttadhalla Chikkahagari

Vedavati Sub-basin

Vedavati (Hagari) Doddavagu Kodihalla

Gundihalla Suvamamukhi Keretore

Chicktore Gamihalla Doddahalla

Jinigehalla Peddavanka Chiimagari

Hagari

47

Tunga Bhadra

The Tungabhadra is an important tributary of the Krishna. It is formed

north of Shimoga, at an elevation of about 610 m by the union of the twin

rivers, the Tunga and the Bhadra, which rise together in the Western Ghats at

Gangamula at an elevation of about 1,197.8 m.

The united river Tungabhadra flows for nearly 531 km in a general

north-easterly direction, through Kamataka and Andhra Pradesh and joins the

Krishna, beyond Kumool, at an elevation of about 264 m. Among the

tributaries of the Tungabhadra may be mentioned the Varada river which

drains a large area of the Western Ghats and falls into the Tungabhadra, at an

elevation of about 509 m, nearly 160 km below the junction of the Tunga and

the Bhadra.

Another important tributary is the Hagari, called the Vedavati in its

upper reach joining the Tungabhadra about 168km above its junction with the

Krishna. The Tungabhadra has a drainage area of 71,417 sq km out of which

the catchment area in the State is 57,671 sq km and like the Bhima, drains

about 206 km length of the Western Ghats. The rainfall in the Tungabhadra

basin drops from 400 cm in the Ghats to 50 cm in the plains.

Vedavati

The river Vedavati known as the Hagari in lower reaches rises near

MuUayyanagiri in the Western Ghats. It flows in the districts of Chickmagalur,

Chitradurga and Bellary of Kamataka and Anantapur district of Andhra

Pradesh covering a total catchement area of 23,498 sq km. It has a total length

48

'^^&iaple/t/ -^ ^Xifd/uM^eolo^ op u,f2fze4/ ^un^ Wtofed/

of 391 km and of which the length in the State is 293 km and forms the

common boundary between Kamataka and Andhra Pradesh for 26 km. It lies

in a low rainfall zone varying from 70 cm to 50 cm.

Utilizable Surface Water

Considering the utilizability of water resources both for consumptive

(chiefly irrigation) and non-consumptive (chiefly hydropower development)

the river flows that can be put to use on a dependable basis in the Krishna river

systems in the State are shown in the table below:

(M.cum) (Figures are approximate)

System Utilisable Water resources

Utilisation in the existing

projects

Utilisation from projects under construction

The Krishna

system

26,800 11,950 6,000

4.4. Significance of Lineaments in Reservoirs

Area in and around Upper Tunga Project to have witnessed neo

tectonism responsible for the geomorphic rejuvenation. Lineament studies

indicate two dominant trends of lineaments in NNW-SSE and NNS-SSE

directions. The graben originate due to tensile stresses in the directions of

35°-215°. Experimental work based on probability distribution of the lineament

intersection points indicated that lineaments are related to geomorphology.

High intensity of lineament intersection points have been observed over

geomorphologically high terrain and low intensity over low areas. The majority

of landforms as such appear to be dominated by endogenic process. The

geophysical approaches have helped extend the basement configuration below

the sedimentary fill.

49

Lineaments and their Importance

A Lineament is mappable simple or composite linear feature of a surface

whose parts align in a straight or slightly curving relationship and that differs

distinctly from the patterns of adjacent features. Presumably a lineament

expresses a subsurface phenomenon.

A lineament is a regional scale linear or curvilinear feature, pattern or

change that can be identified in a data set and attributed to a geologic formation

or structure.

Classification of Lineaments

Based on the length, the lineaments have been classified into 4 groups.

1. Short / minor 1.6 to 10 km

2. Intermediate 10 km to 100 km

3. Long / major 100 km to 500 km

4. Mega > 500 km

However, no uniform classification system has been evolved yet.

Lineaments are well expressed on satellite images because of the low sun

angle, the suppression of distracting spatial details and the regional coverage.

Mapping and analysis of Lineaments

Lineaments are mapped better using aerial photographs, satellite

imageries and other remote sensing data. Large scale data is useful for mapping

minor and micro lineaments whereas small scale data is needed to map major

lineaments and to map mega lineaments normally mosaics of images are

needed. Aerial photographs are the remotely sensed data extensively used for

mapping of lineaments earlier to the launch of Remote Sensing Satellite.

50

Normally, it is difficult to decide whether the mapped lineament is a

fault or not, but if there is a clear displacement/offset then the lineaments can

be identified as a fault. Integration of the lineament map with the available

structural and geological information of the terrain plus field work helps to

decide the nature of the lineaments.

The lineaments are linear features of geological significance extending

in length over a kilometer or more. These linear features usually represent

faults of fi"actures, faults, joint sets, shear zones etc. Remote sensing technique

is found very useful for mapping lineaments. Lineament mapping and analysis

helps in understanding in the following aspects of geology;

• Structural and tectonic aspects of an area under study

• Engineering geological application.

• Ground water exploration

K. Ganesh Raju of MNRMS, ISRO opined that these lineaments might

have formed due to tectonic activities, plate movement, etc. Some of the major

lineaments correspond to faults.

Deep seismic studies carried out have shown very good correlation

between some lineaments and deep faults. The River Tunga is one among the

major Rivers of Kamataka, which are controlled by major lineaments.

Integration with the seismic data has shown that seismic activities have been

found to occur in the vicinity of NNW-SSE to NW-SE trending major

lineaments.

51

Lineaments are useful in detecting ground water potential zones.

Presence of linear dykes may act as barrier for the jfree flow of ground water,

thus pooling ground water preferentially of one side of this body. Hence

identification of dykes is critical in ground water exploration, wherever they

exist.

Advantages of Lineament Studies

Mapping and analysis of lineaments which indicates faults, fractures etc

is a crucial before talking up any engineering geological projects like dam/

reservoir site selection, road/tunnel alignment, harbour, major industries, major

bridge site selection etc. It will be always advisable to avoid weaker zones.

Generally, it is observed that seismicity is also associated with major

lineaments; hence analysis of lineaments is useful for understanding the

seismic status of the terrain.

4.5. Major lineaments of Karnataka and their significance

Several studies have been carried out by many geologists to map, and

analyze the lineaments of Karnataka using remote sensing data . Lineaments

/linear features of almost entire Karnataka were mapped by

(1) Srinvasan and Srinivas (1977),

(2) Under project Vasundhara ( 1991)

(3) Under National Drinking Water Mission (DOS, 1990).

(4) A number of other studies carried out have covered different parts of

Karnataka.

52

Analysis

Correlation of the major lineaments map of Kamataka with the

geological map of Kamataka (GSI, 1981) has brought out the fact that the

density of intersection of major lineaments is high over Dharawar Super Group

and more particularly over Chitradurga Group. The frequency of occurrence of

major lineaments is also high over this group, whereas Deccan Trap is having a

few major lineaments only. Most parts of the Deccan Trap area dies not have

major lineaments.

Peninsular Gneissic Group also has a number of major lineaments.

Many of the major lineaments cut across various rock groups. The presence of

large number of lineaments and high rate of intersection over Chitradurga

Group indicates that this group is structurally more disturbed than other rock

groups.

Origin

Though the origin of number of major lineaments mapped in Kamataka

has not been discussed in depth by many of the scientists, there is a general

agreement that these might have formed due to tectonic activities, plate

movements.

Lineaments studies at dam site

The lineament based on Land SAT imageries. They reported that the

presence of N 10°E trending lineament found towards the east of the dam.

Several state and central govemment agencies are involved in the

hydrogeological investigations of this area. A few technical (unpublished)

reports are available for a preliminary understanding of the hydrogeological

conditions. Some reports from ground water department are also available.

53

The hydrogeology of Tunga River has been studied with the help of

Indian Remote Sensing imageries. The study of subsurface conditions are

development of regional flow modes and fore cast of future ground water

potential were done by Indira (1988).

Interpretation of Landsat Imagery

• The interpretation of LANDSAT Imagery on 1 : 250,000 scale on Red

and Injfrared wave length were used to provide synoptic view which

helps in picking up faults and lineaments.

• The investigation of imageries indicated the presence of N 10° E

trending lineament found towards the west of the dam site.

• In general, it is believed that these lineaments might have formed due to

tectonic activities, plate movement, etc. Some of the major lineaments

correspond to faults.

• Deep seismic studies carried out have shown very good correlation

between some lineaments and deep faults. The River Tunga is one

among the major Rivers of Kamataka which are controlled by major

lineaments.

Integration with the seismic data has shown that seismic activities have

been found to occur in the vicinity of NNW-SSE to NW-SE trending major

lineaments.

Fault Lineaments

Some of the major lineaments of Kamataka represent faults. Parts of the

river courses of Tunga , Hemavathi, Yagachi, Vedavathi, Krishna, Netravathi,

Malaprabha etc follow major lineaments. Some of these are faults (for

example Krishna River) and others may be deep fractures, shear zones etc.

54

''€Aaptm' -4 '^^tud/io^eolo^ op Ufifie^ ^unqa^ ^tafect/

Lineaments and the Seismicity

For long the Southern Peninsular was considered as seismically stable

area. But earthquake which occurred since 1993 having magnitude of 4 and

above of Mercalli scale have throw a light that most of the earthquake have

occurred in the vicinity NNW-SSE to NW-SE trending major lineaments.

This indicates that a moderate to high seismic activity is wide spread in the

area. The proximity of this activity to major lineaments again indicates that

some time or the other they have been reactivated (NRSA) 1981).

270

180

Fig. 7. Lineaments Rose Diagram

55

'^€Aafd&i/ -4 '~^{ijA'uuj,e,oiot^ op Ufifie^' ^un^ ^tafeci/

n

A

INDEX

Lineament

20 Kilometers

Fig. 8. Lineament Map of Tunga River Basin

56

'~<iAafiet' -4 '~^{ifdAo^ealaq4^ of i/ppe^ '%un^ ^tofect'

SKETCH SHDliJING LINEAMENTS IN AND AROUND

U.T.P. DAM AND TUNNEL SITES H

Scale 1 cm = 1 km

S> SHIMOGA

U.T.P. DAM SITE

LINEAMENTS

Fig. 9. Lineaments in and around dam site

57

4.6. Ground Water Potential

It has been well established by many studies that lineaments and their

intersections are high prospective zones of ground water explorations. Some of

the major lineaments of Kamataka are known to have good ground water

potential.

Yield of bore wells located over the lineaments are found to be high .

Naganna (1979) opined that the E_W running lineaments in Kamataka are

transporting ground water from the surplus Western Ghta region to the eastern

part of the state. Naganna and Lingaraju (1990). It is reported that yield of bore

well is high in the lineaments area than on the other areas.

Water Table

"Ordinarily the soils and rocks are saturated with water below a certain

depth. The top of this saturated zone is known as the water table. "The gradient

of the water table at any place is a function of the size and number of the

interstices or openings in the ground and the quantity of water. A steep water

table thus indicates tight ground with small interstices, or very large quantities

of water;, conversely, a flat water table indicates large openings in the rocks or

very small quantities of water.

Estimates of the conditions which might affect the amount of leakage

must be based on observations of rock lithology, structure and degree of

weathering combined with those on the existing groundwater regiment of the

immediate region. The configuration of the water table will not only indicate

the magnitude of the unsaturated area through which leakage may take place

58

but also the steepness of slope of the water at different seasons; and taken into

account with the size of the confluent recharge area, is a valuable though

complicated index of the average permeability of the rocks.

As the leakage must be resisted by the characteristics of the ground,

study of a site for a reservoir is a geologic and more particularly a groundwater

problem. To solve this problem completely the position and movements of the

ground water under natural conditions must be determined.

Relation to abutments

The lower end of a reservoir is usually the most critical end. Here the

water is impounded to the greatest height above the original stream level and is

unavoidably raises above the water table. Moreover, the natural walls of the

reservoir generally have the least thickness at the lower end. With great

difference, within a short distance, between the water table and water level in

the reservoir, a steep hydraulic gradient away from the reservoir will result,

with corresponding danger of excessive leakage.

Relation to Reservoir

Where permeable rocks are present, the position and slopes of the

underground water surface, or water table, should be ascertained. In most

drainage basins, the water table practically coincides with the topographic

surface near the streams and rises toward the ridge creates, although at a more

gradual slope than the surface of the ground. Such a condition indicates that the

underground water of the basin is moving slowly toward the streams that drain

and basin, and consequently, that the proposed reservoir will be more likely to

receive than to lose water by underground flow.

59

•

'"SAapt&i/ -4 '^^C^dw^.ealoft^ of u^ip&i/ '%un^ ^lofecl

Factors affecting the Water table

In general, some of the features that may influence the elevation of the

water table in any large valley and cause irregularities and fluctuations of the

water table are:

• The water table usually slopes with, but less steeply than the land

surface. The slope is away from the sides and towards the center of the

valley.

The water table varies with its proximity the canyons controlling large

or small drainage areas. The water table will be higher in that portion of

valley close to canyons controlling large drainage areas.

The level of the water table changes with the season. This is due to the

difference in amounts of water taken into, and to the difference in rate at

which the water is discharged from the zone of saturation with different

seasons. The amount of change at different pomts will depend upon

number of factors. These factors should be investigated.

All rocks are somewhat permeable and some loss of water is inevitable

from any reservoir, which abuts on rock masses lying above the pre­

existing water table. If the level of impounding does not exceed that of a

pre-existing adjacent groundwater body, storage has been established i n

the previously unsaturated rocks. Conditions and rates of groundwater

flow on the opposite side of the groundwater divide will remain the

same since the hydraulic head is unchanged.

60

'~€AapteA/ -4 '^^tifd/Mfeolofi^ op upfze^ %u*ifa/ ^lafecl

Watertable Contours

The watertable in observation wells are monitored by the Department of

Mines and Geology (Groundwater Division) of Govt, of Kamataka. The data

available from 29 observation wells have been appended for the preparation of

maps and numerical assessments. The average water levels of a long term data

(lOYears) of observation wells can give a general and regional hydraulic

condition including the direction of groundwater flow (Brozoky et al, 1973).

The watertable contours can summarize the information about the state;

extend of the zone of saturation, gradient, direction of movement of

groundwater, the places or zones of outflow from and inflow into the

groundwater system. Representation of watertable by conventional contour

maps showing the elevation of water level above mean sea level is rather

generalized in nature, being not capable of bringing out the pertinent features

of the dynamics of groundwater flow and is often liable to subjective errors

(Biswas et al, 1967). This is true in the case of hard rock areas like Tunga

basin where groundwater occurs in the weathered, jointed, fractured and

fissured pockets with variable dimensions.

4 .̂1324 Effect of Geology on Regional Flow System

Subsurface stratigraphy and the resulting variations in hydrogeological

parameters can also make a large number of deviations in the flow regime. The

tertiary sediments as well as alluvium of the basin are the promising potential

zones where the flow conditions would be normal. The existence of quartzite

hills controls the geometric configuration of the aquifer media and also the

flow characteristics to be considered for stream-aquifer interaction.

. (^a)C< /j / Vijvempu University L'brarv V J o N i l 61 >'3na Sahyadr;, Gh.r.karavjhatta

''^AapleA/ -4 '^Xj^iofoolo^ op '^Upp-e/i/ '%un(^' 'tPtOfocl

' • 7 ' • • (•

A 10 10 Kilometers

Contours of 10 isoresistivity

Fig. 10. Tonga river system aquifer

62

'~^Aapie/i/ -4 '^ijAnxu^eoio^ op olpp&i/ ^un^^ ^f'loj.e^l

Ground water flow

Tunga river

10 0 10 20 KJIometers

Fig. 11. Groundwater flow direction of Tunga river system

63