one of the oldest systems in tamil nadu is the “kodaiyar

Kodaiyar River Basin

Introduction

One of the oldest systems in Tamil Nadu is the “Kodaiyar system” providing irrigation

facilities for two paddy crop seasons in Kanyakumari district. The Kodaiyar system comprises the

integrated operation of commands of two major rivers namely Pazhayar and Paralayar along with

Tambaraparani or Kuzhithuraiyur in which Kodaiyar is a major tributary. The whole system is

called as Kodaiyar system. Planning, development and management of natural resources in this

basin require time-effective and authentic data.The water demand for domestic, irrigation,

industries, livestock, power generation and public purpose is governed by socio – economic and

cultural factors such as present and future population size, income level, urbanization, markets,

prices, cropping patterns etc.

Water Resources Planning is people oriented and resources based. Data relating to

geology, geomorphology, hydrogeology, hydrology, climatology, water quality, environment,

socio – economic, agricultural, population, livestock, industries, etc. are collected for analysis. For

the sake of consistency, other types of data should be treated in the same way. Socio – economic,

agricultural and livestock statistics are collected and presented on the basis of administrative units

located within this basin area.

Location and extent of Kodaiyar Basin

The Kodaiyar river basin forms the southernmost end of Indian peninsula. The basin

covers an area of 1646.964 sq km. The flanks of the entire basin falls within the TamilnaduState

boundary. Tamiraparani basin lies on the north and Kodaiyar basin on the east and Neyyar basin

of Kerala State lies on the west. This is the only river basin which has its coastal border adjoining

the Arabian sea, the Indian Ocean in the south and the Gulf of Mannar in the east.

The basin is bifurcated into 6 sub basins on the basis of drainage pattern. The Kodaiyar

river basin covers in the following Survey of India topo sheets:58H/2, 58H/3, 58H/4, 58H/6,

58H/7,58/H8, 58H/11 and 58H/12 of scale1:50,000 within the co-ordinatesLatitude: 08º 04’ 34” -

08º 34’ 35” and Longitude: 77º 05’ 53” - 77º 35” 39”. The entire basin falls in the territory of

Kanyakumari district and a small portion falls in Radhapuram block of Tirunelveli district.

The Kodaiyar river basin is spreading over 4 taluks in Kanyakumari district and part of

one taluk of Tirunelveli district. Out of 10 blocks in this basin 6 full blocks comes under

Kanyakumari District and one part block from Tirunelveli District are also included. Four

Municipalities namely Kuzhithurai, Nagarcoil, Kolachal and Padmanabhapuram are located in

this basin.

Kanyakumari is the major tourist part of India which is famous for confluence of three

seas of Indian Ocean, Arabian sea and Bay of Bengal. Vivekananda rock, Thiruvalluvar statue and

Gandhimandabam are some of the important tourist places. Suchindram is famous for the holy

place of Hindus and Padmanabhapuram is having the famous Palace of an ancient king. This basin

are well connected with national highways, State highways and railway lines.

The administrative setup of the Kodaiyar river basin is given in Table-1.

Table-1: Administrative Setup Of Kodaiyar River Basin

Sl.No. District Taluk SubBasin Block

Block /Area

Falling Withinthe

Basin AreainSq

Km

1 Kanyakumari Kalkulam

Valliyar

Killiyur 10.399

Kalkulam Thiruvattar 0.887

Kalkulam Kuruthankode 91.277

Agastheeswaram Rajakkamangalam 10.896

Thovalai 12.354

Thakkalai 99.713

TOTAL 225.526

Kalkulam

Perunchani

Thiruvattar 85.670

Thovalai Thovalai 69.128

TOTAL 154.798

Kalkulam

Pechiparai

Thiruvattar 111.762


Vilavancode Melpuram 56.701

TOTAL 168.591

Kalkulam

Kuzhithuraiyar

Killiyur 77.453

Kalkulam Thiruvattar 78.818


Kalkulam Thakkalai 32.047

Vilavancode Munchirai 72.010



TOTAL 351.341

Kalkulam

Chittar

Thiruvattar 47.317


TOTAL 173.006

Kalkulam

Pazhayar

Thiruvattar 19.753


Kalkulam Thakkalai 5.042


Agastheeswaram Rajakkamangalam 133.541

Agastheeswaram Agastheeswaram 14.421

2 Tirunelveli Radhapuram Radhapuram 132.000

TOTAL 573.702

TOTAL AREA 1646.964

The administrative map of Kodaiyar river basin is shown in Fig.

Fig. Administrative map of Kodaiyar river basin

The river Tamiraparani (also called Kuzithuraiyar river) originates from the Western Ghats

and flows towards the west in the Kanyakumari district and drains into the Arabian sea near

Thengapattinam, The Kodaiyar river has three major tributaries namely Kodaiyar, Paralayar and

Chittar. After the confluence of Kodaiyar with Paralayar, the river Kuzhithuraiar flows south

towards the sea. Paralayar river has four tributaries namely Kalikesanar river, MasipatiAr, Chittar river and

Pambar river which originates from the southern slope of Western Ghats at about 1500m above

M.S.L.Perunchani Reservoir is located on the confluence point of tributaries across

Paralayar.After the confluence of Kodaiyar and Paralayar the Mulliar joins Thamiraparani river

near Thirukurichi village. The above tributaries join together and form a natural lake called

“Perunchani Lake”.

Ulakkaruvuar is also a tributary of Pazhayar river. Another tributary originates in the

southern slope of Western Ghats from Nallakaimottai and Attumottai at an altitude of about 800m

above M.S.L. near Black Rock estate and lower Victoria estate. Yet another tributary called

Alathuraiyar originates in the southern slope of Western Ghats form Mahendragiri hills and finally

joins Pazhayar river near Dharisanamcope. The Pazhayar finally enters the Arabian sea near

Manakudy after traversing a distance of 35 km.

Another tributary originating in the Western Ghats from Vallimalai and MaruvattarKundru

at an altitude of about 900m above M.S.L. These tributaries join together at Karavilai village.

One more tributary originates near Kotanallur area and joins Valliar river near Muttalakurunchi

village.

The Kodaiyar river basin in general is slopping towards southeastern direction with a

rugged topographical relief and an undulating terrain.The Kodaiyar reservoir is located in

between Virapuli reserved forest on the east at an elevation of 544m above M.S.L and Kalamalai

reserved forest on the west at 529m above M.S.L. adjacent to Kodaiyar and Paralayar, there are

two distinct and separate small basins namely Pazhayar and Valliar basins.On the eastern part of

the basin the Mahendragiri reserved forest at an altitude 530m above M.S.L is located.

Drainage The river Kodaiyar is the main river in this basin. The overall drainage of this basin is

dendritic in nature. The Perunchani dam is constructed on Paralayar upstream and the Pechiparai

reservoir situated on the northern territorial part of the basin. The Kodaiyar I and Kodaiyar II dam

are situated west of Pechiparai reservoir. Kuttiar is another major tributary of Kodaiyar.

The Chittar I and Chittar II lies west of the basin.Radhapuram canal runs south of

Terkumalai (247m above M.S.L). Below Pechiparai reservoir, two main tributaries join the

Kodaiyar river. One, called as Chittar I which originates at 500m above MSL in the reserved

forest of western Ghats and join the Kodaiyar river on the leftern flanks. The other tributary,

Chittar II originates at 600m above MSL. On contrast the upper catchment of Kodaiyar above

Pechiparai (part of western Ghats) is covered with thick jungle. The river Valliyar runs south of

Takkalai through Eraniel and down to Manavalakurichi.

One of the tributaries of Pazhayar is called Thadaviar or Taruvannar river which originates

in the south-western slope of Western Ghats from Karumpara near Mahendragiri estate at an

altitude of about 1090m above M.S.L. and joins Pazhayar river at Viravanallu. The drainage map

of Kodaiyarriver basin is shown in Fig.

Fig. Drainage map of Kodaiyar river basin

Geology

For the geological study, the district resource map from Geological Survey of India is

used.Major part of the Kodaiyar river basin area is underlain by gneissic terrain of hard crystalline

rocks which includes Charnockites and Khondalites.Migmatite gneiss and Granites overlain the

hard rocks and are identified as Warkalai sand stones which is equivalent to Cuddalore sandstone.

Also, the sands of recent origin are noticed along the coast. Khondalite and Charnockite Groups of

Archaean age occur in the western hilly area and in the plains migmatite-gneiss of Archaean age

is found to occur. The coastal plain hosts rocks of Miocene, Quaternary and Recent ages.

In the southern part of the basin along the west coast, placers deposits of heavy minerals

(including illmanite, rutile, garnet and monazite) occur as localized pockets between Kolachel and

Kanniyakumari. Beach Sands are exposed west of Kanyakumari, Rajakkamengalam,

Manavalakurichi, Marthandam and Kuzithurai along the west coast in Kanyakumari district. Of

these, the area near Manavalakurichi is well known for the occurrence of illmanite

ores.Significant concentration of placer deposits occur between Vattakottai and Lipuram, the

famous Manavalakurichi deposits, which extends over a length of 5 to 6 km. with a width of 3 to 5

m. The geology map of Kodaiyar basin is shown in Fig.

Fig. Geology map of Kodaiyar river basin

The geomorphological landforms identified in Kodaiyar river basinis shown in Fig.

Fig. Geomorphology map of Kodaiyar river basin

Land use

The detailed landuse categories are given in Table-2.

Table-2: Areal Extent of Various Landuse Categories

Sl. No. Level I Level II Area in Sq.km.

I Built Up Land Town & Villages 63.397

II Agricultural Land

CropLand 163.201

Fallow land 101.755

Plantation 186.215

Total 451.171

III Forest

Dense forest 79.636

Plantation 43.928

Reserved forest 653.193

Total 776.757

IV Waste land

Beach sand 16.387

Land with Scrub 89.742

Scrub/Shrub land 107.273

In the command area the three main soils namely lateritic, red soil and brown soil are

occur in the blocks of Thiruvattar, Munichirai, Kurunthencode, Rajakkamangalam, Killiyoor,

Thuckalay and Melpuram. Mixed types of red and alluvial soil occur in Agastheeswaram and

Thovalai blocks. Soils are mostly red loam and lateritic in nature with coastal alluvium in the

western side. Lime status is Nil due to occurrence of more area under acid condition. The soil pH

generally ranges from 4.5 to 8. The soil map of Kodaiyar river basin is shown in Fig.

Fig. Soil map of Kodaiyar river basin

From the study, it is noticed that the groundwater potential is very good in alluvial plain,

good in valleyfill sediments and deep pediment zones, moderate in coastal plains. Very good

groundwater potential zones are found to occur in and around Neyyur, Tikkanamkad, Karupaai,

Vembanur, Kurusadi villages. The good groundwater potential zones are identified in and around

Villukkiri, Kuzhithurai, Thiruvankad, Nagarcoil, Tazhakudi, Tittuvilai, Kadukkarai, Triparappu

and Maniyankuzhi villages. The moderate groundwater potential zones occurred in

Land without Scrub 65.671

Total 279.073

V Water Bodies

Reservoir 37.324

Tank 15.602

River/Canal 19.95

Total 72.876

VI Others Salt pan 3.69

Grand Total 1646.964

Srilakshmipuram, Unnamalakadi, Kaviyanallur, Mulakumudu, Eraniel, Suchhindram, Pudur and

Kanagappapuram villages and surroundings. Poor groundwater potential zones are noticed in and

around Nelvettti, Toduvetti, Tottavaram, Neduvilai village and area wherever rocky out crops and

Pediment zones are occurring.

Sea water intrusion

Sea water intrusion study in Kanyakumari district is restricted to 10km width to the entire

coastal length of 83km covering a total area of 830 sq. Km. Water level near the coast varies from

0.3 to 14m and in elevated terrain it is lowered down to 28m from ground level observed during

the year 2008.15 numbers of control wells, 8 numbers of sea water intrusion study wells and 6

numbers of piezometers have been selected in this area and are used for water level monitoring

every months and water quality studies during pre monsoon period and post monsoon period

every year.

The ground water level observed from the monitoring wells on the eastern part of the

coastal area in Kodaiyar basin has down below the MSL particularly in Suchindram, Mylady,

Bagavathipuram, Ammanakkavilai and Agastheswaram. Similarly the Chloride bi- carbonate ratio

of water samples for the above mentioned wells also more than 2.0 and a maximum of 3.5. Also in

the western part of the coastal area covering part of Munchirai, Kiliyur and Takkalai blocks, the

Chloride-bi-carbonate ratio value of 6.5 has been observed at the observation wells located at

(93044) in Munchirai blocks. The ground water level south of Munchirai at Pallithottam (SWA1)

has gone down below MSL(-2.16m). From all these factors, it is clear that the coastal area of

Kodaiyar basin are under the thrust of seawater intrusion. In the rest of the area both the ground

water level and quality of water is within permissible limit. The sea water intrusion study map of

Kodaiyar river basin is shown in Fig.

Fig. Sea water intrusion study map of Kodaiyar river basin

Demographic details

The sub basin wise population of Kodaiyar river basin is given in Table- 3.

Table-3: The Urban and Rural Population as per census 2010 (in Million)

Sl.

No. Name of the Sub

basin

Urban Population

in Million in 2010

Rural Population

in Million in 2010

Total Population

in Million in 2010

1 Valliyar 0.258 0.112 0.370

2 Perunchani 0.000 0.007 0.007

3 Pechiparai 0.000 0.002 0.002

4 Palayar 0.473 0.222 0.695

5 Kuzhithuraiyar 0.457 0.315 0.772

6 Chittar 0.109 0.013 0.122

TOTAL 1.297 0.671 1.968

Kanyakumari district has a high population density of 995.7 persons per sq.km

(2001). In Kodaiyar basin, the population density is the highest in Kuzthithuraiyar sub basin (2230

Persons per sq.km) and the lowest is at Pechiparai sub basin (11.86 Persons per sq.km). The sub

basin wise population density of Kodaiyar basin is given in Table-4

Table-4: Sub basin wise population density of Kodaiyar river basin

Sl.No Name of the sub

basin Area

(Sq.km)

Total Population

in Million in 2010

Density

Persons/sq.km

1 Valliyar 225.526 0.370 1730.00

2 Perunchani 154.798 0.007 45.22

3 Pechiparai 168.591 0.002 11.86

4 Pazhayar 573.702 0.695 1265.00

5 Kuzhithuraiyar 351.341 0.772 2230.00

6 Chittar 173.006 0.122 705.00

Industrial Employment

In this state, Kanyakumari is the only district with soil, rainfall and topography for the

growth of natural rubber trees. Although there are many private processors of natural rubber,

Arasu Rubber Corporation, Nagercoil which come into existence with effect from 1-10-84 is a

major processor in this field. The corporation has an extent of 4279.78 hectares of rubber

plantations. The process is being monitored by six rubber division are Keeripparai, Keeripparai

factory, Manaloda, Chittar, Mylar, Kodayar.There are 3 rubber factories at Keeripparai,

Perunchani and Mylar. There are 6,89,054 tappable rubber trees under the corporation. There are

2143 workers are employed in the corporation, out of which 478 workers are Srilankans

Repatriates. Good welfare facilities to the labours are being maintained.

The Y.N.C.A rural re-constuctioncentre at Marthandam is one of the oldest institutions in

India which is a boon for those engaged in bee-keeping and its products are much in demand

throughout the nation.There are 23 rural industries and 10 Khadi sub centres in the district. The

statistics on the Khadi village industries are 9 Khadi stores, 2 Soap units and a Footwear unit.

As per Handloom census 1995-96, there are 15,853 handlooms. The major Co-operative

societies providing employment to weavers in Kanyakumari district are64 Primary Handloom

Weavers Co-operative Societies,16 Industrial Weavers Co-operative Society, 1Powerloom

Weavers Co-operative Society and 1 Weavers Co-operative Societies Federation.Average annual

production of handloom varieties is Rs.1800 lakhs and annual average sales value is Rs.2100

lakhs.As a foreign exchange earnet, this industry has a distinct place in the industrial map of

Kanyakumari district.

There are 183 cashew industries which provide employment for about 2800 women.There

are 9959 permanent small scale industrial units and 20,136 provisional small scale industrial units.

RubberIndustriesPark to provide infrastructure / utilities arrangements for Rubber goods

manufacturing units with export thrust, is under implementation, in the

Chenbagaramanputhurvillage of Kanyakumari District through TamilNaduIndustrial Park

(Rubber) Ltd, a joint venture company. Govt. of India granted “in-principle” approval for

establishing this project as an SEZ in November 2005. The total cost of development has been

estimated @ Rs. 14.52 Crores. The company has completed financial closure and land

procurement is under progress. This project is expected to generate exports of about Rs.300 crores

and provide direct employment of about 1,000 persons.

Hydrometeorological characteristics

Considering the distribution of rain gauge stations and the availability of data, 14 rain

gauge stations having long-term records in the basin are considered for the detailed analysis.The

sub basin wise annual dependable rainfall of Kodaiyar river basin is given in Table- 5.

Table 5 - Annual Dependable Rainfall (in mm)

Sl. No. Name of the

SubBasin 25% 50% 75% 90%

1 Valliyar 359.91 313.83 251.63 178.04

2 Perunchani 322.93 289.11 248.01 193.85

3 Pechiparai 378.08 325.24 273.71 232.79

4 Pazhayar 694.08 595.72 507.26 388.64

5 Kuzhithuraiyar 565.38 486.02 403.05 280.79

6 Chittar 336.47 258.06 207.58 154.84

The annual average rainfall of the basin is 1526.96 mm.

Climate

The weather station considered for analysis is Aralvoimozhi maintained by PWD (GW).

The climatological values of this river basin are given in Table-6.

Table-6: Climatological Parameters

S.

No Climatological Parameter Aralvoimozhi

1 Average monthly temperature

Maximum. in. 0 Celsius 32.06

2 Average monthly temperature

Minimum. in. 0 Celsius 26.02

3 Average mean temperature in 0 Celsius 29.04

4 Average relative humidity in % 68.65

5 Average wind velocity in km/hour 7.94

6 Average Sunshine hours / day 6.95

7 Pan Evaporation in mm 231.64

Surface Water Data

There are 2092 system tanks and 55 non system tanks situated in the basin.

The influential rainfall stations having long-term records considered for analysis is given in Table-

7.

Table-7: Raingauge stations considered for analysis

S.

No.

Name of

subbasins

Subbasin

area

(Sq.Km.)

Raingauge stations

1 Valliyar 225.53 Eraniel, Mulagumoodu, Thukalay

2 Perunchani 154.8 Keeriparai

3 Pechiparai 168.59 Palamore, Pechiparai

4 Pazhayar 573.7 Aralvoimozhi, Boothapandi, Kottaram,

Nagercoil

5 Kuzhithuraiyar 351.34 Kuzhithurai, Meekodu, Puthan Dam

6 Chittar 173.01 Kalial

Total 1646.96

Monthly Runoff Simulation (MRS) Model assesses the Surface Water Potential for 75%

Dependable yield for southwest, northeast and non-monsoon periods and are given in Table-8.

Table-8: 75% Dependable Surface Water Potential for Kodaiyar River Basin

Sl.

No.

Name of Sub

basin

75% Dependable Surface Water

Potential in MCM

SW NE NM Annual

1 Valliyar 67.88 160.34 23.41 251.63

2 Perunchani 89.73 99.44 58.84 248.01

3 Pechiparai 136.27 68.73 68.7 273.71

4 Pazhayar 247.73 88.86 170.67 507.26

5 Kuzhithuraiyar 192.37 108.28 102.41 403.05

6 Chittar 87.87 92.86 77.33 258.06

Total 821.85 618.51 501.36 1941.72

Surface Water Potential of Kodaiyar River Basin is 1941.72 Mcum.

THE EXISTING SURFACE WATER SUPPLY SYSTEMS

RESERVOIRS UNDER PWD

Pechiparai Dam

This was built across Kodaiyar river about 1.6 km below the confluence of the three

tributaries Kallar, Suttar and Kuttiar at Pechiparai. The site is about 11 kms. North of

Kulasekaram and 45 kms from Nagarcoil. It is at a latitude of 08°30'00" N and longitude of

77°08'30" E.

The gross and net capacity of the reservoir is 152.36 MCM and 126.02 MCM respectively.

The length of dam is 555.35 m and maximum height is 46.32 m There is no inspection gallery.

This is a solid gravity dam with a surplus regulator of 6 vents (12.19 m x 4.57 m). The dead

storage of this dam is 26.34 MCM which is 17.3 percent of the total storage.Based on the DSRP

suggestion the upstream face treatment of Pechipparai dam was completed on 30.06.1998. The

Dam was grouted with non shrink cementations material by grout injection and the joints were

finished by epoxy sealant to an extent of 938.86 m2 at an estimate amount of Rs. 82 lakhs under

dam safety.Now the seepage at the areas grouted are considerably reduced and whereas the

seepage increased in the non-grouted areas. Hence it is a must and necessary to treat the balance

area immediately which is 7395 m2.

Perunchani Dam

This was built across the river Paralayar at Perunchani, a place about 10 kms. East of

Kulasekaram and about 42 kms. Northwest of Nagarcoil. It is at a Latitude of 08°25' N-and

Longitude of 77029' E. The dam is across a picturesque valley between two hillocks forming an

ideal site. The capacity of the reservoir is 81.84 MCM (2890 Mcft). The dead storage is negligible

in this dam .

The dam is a straight gravity masonry dam of 308.46 m long with a surplus regulator of 4

vents (12.19 m x 4.57 m). A drainage gallery of 1.52 m x 2.29 m has been provided in the middle

river section for a length of 45.70 m which serves as longitudinal inspection chamber as well as

outlet for the seepages from the foundation. For the remaining length of dam 0.60 x 0.60 m

drainage duct connecting the vertical drainage shaft has been provided.

Construction joints has been provided at 7.5 m intervals in the body of the dam.The F.R.L.

of this reservoir has been raised by 1.83 m from 91.44 m (300.00 ft) M.S.L. to 93.27 m (306.00 ft)

M.S.L. keeping the M.W.L. and F.R.L. at the same level so as to increase the existing capacity.

The increased capacity is 16.71 MCM (590 Mcft). Electrical crane arrangements made for

operating emergency shutter for river sluice.

Chittar Dam I

The Chittar Dam I was constructed during the period 1964-70 across the river Chittar-I at a

latitude of 08°28'00" N and longitude of 77°15' E. The river has its source in the mountains in

Kalamalai Reserve Forest, near Ettukani and Vandiplavukani at an elevation of about 422 m

above M.S.L. and is at about 2 kms. upstream of the confluence of the river with Kodaiyar. The

gross and net storage of this dam is 17.28 MCM (610 Mcft.) and 11.13 MCM (393 Mcft.)

respectively, leaving a dead storage of 6.14 MCM (217 Mcft). Here also, the dead storage is very

high and it's percentage to the gross storage is 35.5.

Chittar Dam II

The Chittar Dam II was also constructed during the period 1964-70 across the river Chittar

at a latitude of 08°26'55" N and longitude of 77°15' E the river has its source in Kalamalai

Reserve Forest at an elevation of about 687 m above MSL and is at about 2 kms upstream on the

Southern and Eastern slopes of Kurinchimalai. After running a distance of about 10 kms, it

merges at Sivalogam Estate to form Chittar II and then flows for 4.8 kms. and joins with

Kodaiyar. The gross and net storage of this dam is 28.55 MCM (1,009 Mcft.) and 16.99 MCM

(600 Mcft) respectively. Here also the dead storage is 11.58 MCM (409 Mcft) which is very high

and it is 40.5 percent to the gross storage.

The purpose of construction of the two reservoirs are only to supplement the ayacut under

Kodaiyar Left Bank Canal. So, these two reservoirs have no independent channels and command,

but they have been connected to Kodaiyar Left Bank Canal. Chittar Dam I and II are connected by

an interconnecting channel (open cut) in the foreshore of the two reservoirs. Hence the full

reservoir levels of the two reservoirs are same. For the calculation of yield, storage position in the

reservoir, etc. they may be taken as one single unit. The water from Chittar Dam I is taken to

Kodaiyar Left Bank Canal (K.L.B. Canal) through a canal which joins K.L.B. Canal at L.S. 10.46

kms.

Poigaiyar Reservoir

Poigaiyar reservoir was constructed across Poigaiyar river (a small jungle stream) at

77°31'45" E longitude and 08°16'00" N latitude near Aralvolmozhy of ThovalaiTaluk) in

Kanniyakumari District. The gross and net capacity of the reservoir is 2.70 and 2.51MCM (68.70

and 61.97 Mcft) respectively.This reservoir is a composite dam with earth dam from L.S. 0.0 m to

1174 m and masonry dam from L.G. 1174 to 1230 m (uncontrolled weir). Total command area

benefitted works out to 249.7 ha. which includes stabilization, bridging the gap, conversion of

single crop to double crop and new dry crop ayacut.

As Government is giving top priority for drinking water, the sole purpose of constructing

this reservoir for irrigation is now modified and 0.57 MCM (20 Moft.) is earmarked for domestic

water supply to the villages in ThovalaiPanchayat Union. Due to this, the proposed new dry crop

area has been reduced from 202.4 ha. to 121.4 ha.

Mambazhathuraiyar Reservoir

The Mambazhathuraiyar reservoir scheme is located at about 3 Km from Villukuri village

which is on the Nagercoil Trivandrum main road and is situated at East Longitude 77023’0” and at

North latitude 8014’0” near Anaikidangu in Villukuri village which contemplates the formation of

reservoir with an effective capacity of 44.54 M.cft (1.26M.cum ) across Mambazhathuraiyar river

in KalkulamTaluk of Kanniyakumari District.

The river Mambazhathuraiyar originates from MaruthathoorMalai at an altitude of

838m(2750ft) MSL and reaches the plains at an elevation of 76m(250ft) MSL and flows for about

4Kms (2½ mile) in the same name, after which it is known as Thuvalar. Thuvalar flows for about

2.4 Kms (1½ mile) and then joins with Valliyar river near Thuckalay, which originates from

Vellimalai hills and then flows towards south and falls into Arabian Sea near Kadiyapattanam

with total length of 19.20 Kms (12.00 miles ) from its origin. The free catchment area up to the

proposed reservoir site works out to 7.25sq.km (Hilly ). Necessary canal system is also proposed

for giving assured supply to the existing ayacut of 184.44haunder this river and 6 rain fed tanks

and also to divert the excess yield into Erattakarai branch channel of P.P. channel under Kodayar

system. This diverted quantity can be conserved in Kodayar to utilize in some other areas to bring

dry lands of 182.11ha under plough.The hilly catchment area spread over to an extent of

7.25sq.km at an Altitude ranging from 76m (250ft) to 833m (2750ft) MSL. The catchment areas

are influenced by both Southwest and Northeast monsoon.

Reservoirs under TNEB

Kodaiyar (Upper) Dam I

Kodaiyar Dam I, also called as Upper Dam was constructed by Tamilnadu State Electricity

Board during the period 1963-72 to generate electricity. In the upper reach, that is, at the starting

point, Kodaiyar has two arms. This dam has been constructed across the left arm of Kodaiyar

which has its source in Virapuli reserved forest area and the highest peak from where it originates

is about 1800 m above MSL. The capacity of the Upper Dam is 118.50 MCM (4185 Mcft) and the

installed power production capacity is 60 MW.

In order to augment the water supply to Kodaiyar Dam I which also indirectly benefits

Kodaiyar Dam II for producing electric power, two dams have been constructed across Kuttiar

called Kuttiar Dam and Chinnakuttiar Dam during 1973-1976. The water from Kuttiar Dam is

taken by a flume to Chinnakuttiar Dam from where water is pumped to Kodaiyar Dam I.

Kodaiyar (Lower) Dam II

Kodaiyar Dam II, which is also called Kodaiyar Lower Dam was also, constructed by

Tamilnadu State Electricity Board during the same period of construction of Kodaiyar upper dam,

i.e., during the period 1963-1972. This dam also receives the tail waters of Kodaiyar Power House

I and acts as forebay for Kodaiyar Power House II, the tail waters of which are let into Pechiparai

Reservoir through a channel. The capacity of the reservoir is 0.883 MCM (31.20 Mcft) only and

the installed power production capacity is 40 MW.The State Electricity Board is releasing the

water from the above two reservoirs according to the rules framed by the Government of

Tamilnadu.

Kuttiar Dam

The Kuttiar Dam was constructed during the period 1973-1976 across the river Kuttiar at a

Latitude of 08°31 '30" N and Longitude of 77°20'22" E. The river has its source in

KachechapanMalai of Veerapuli Reserved Forest at an elevation of about 1500 m above MSL.

The capacity of the dam is 0.227 MCM (8 Mcft). The water collected in this Dam is diverted to

ChinnaKuttiar Dam (Weir) by means of a flume of length 710.18 in with a carrying capacity of

5.66 cumecs.

ChinnaKuttiar Dam

The ChinnaKuttiar Dam was constructed during the period 1973-1976 across the river

ChinnaKuttiar at a Latitude of 08°30'52" N and Longitude of 77°20'50" E. The river has its source

from Veerapuli Reserve Forest and KachechapanMalai at an elevation of about 1500 m above

MSL. The capacity of the dam is 2.776 MCM (98 Mcft). This dam also receives water from

Kuttiar Dam through a flume. The water thus collected from ChinnaKuttiar Dam and received

from its own catchment area is then pumped to a height of 33.53 m (110ft) with 2 numbers of 650

HP each, into Kodaiyar Dam I to augment the storage.

The ayacut details of channels in Kodaiyar system is given in Table-9.

Table-9: Ayacut Details of Channels in Kodaiyar system

Sl.No Name of Channel Reach Sluice

No.

Direct

Ayacut

Ha.

Indirect

Ayacut

Ha.

Total

Ayacut

Ha.

I.

1.

Anandanar Channel

L.S. 0 to 12000 m

Head 1 to 25 1155.49.0 159.25.5 1314.74.5

Total 1155.49.0 159.25.5 1314.74.5

2. L.S. 12000 to 24000 m Middle 26 to 71 2615.48.0 591.04.5 3206.52.5

Total 2615.48 591.04.5 3206.52.5

3 a.

b.

c.

d.

e.

f.

g.

h.

i.

j.

A.K.Kal - 400 m Tail 07 Nos. 134.96.0 57.58.0 192.54.0

West kal – 3400 m 18 Nos. 228.94.0 85.22.5 314.16.5

KrishnankoilKal – 2200 m 14 Nos. 103.53.0 97.67.5 201.20.5

AsaripallamKal – 7000 m 15 Nos. 232.38.0 60.50.0 292.88.0

East Main Channel – 5600 m 08 Nos. 145.10.5 - 145.10.5

Karavilai Channel – 8000 m 21 Nos. 334.39.0 - 334.39.0

Athikadai Channel – 10,600 m 26 Nos. 352.23.5 109.71.0 461.94.5

Thengamputhoor Channel –

3600 m 12 Nos. 253.41.5 83.83.0 337.24.5

Kottar Channel – 3620 m 03 Nos. 99.71.5 82.06.5 181.78.0

Chambakulam Channel 22 Nos. 217.60.5 182.20.0 399.80.5

Total 2102.28.0 758.78.5 2861.06.0

II.

1.

Thovalai Channel

L.S. 0 to 24000 m

Head 1 to 28 815.72.5 550.54.5 1366.27.0

Total 815.72.5 550.54.5 1366.27.0

2. L.S. 24000 to 48800 m Middle 29 to 67 2169.90.0 857.30.5 3027.20.5

Total 2169.90.0 857.30.5 3027.20.5

3.

a.

b.

c.

d.

e.

M.M. Channel and Branch

Channel Tail -

West branch channel - 152.22.5 11.74 153.96.5

East major channel - 252.63.0 10.93 263.56.0

East minor channel - 93.11.5 50.60.5 143.72.0

Nilapparai channel - 428.74.5 285.42.5 714.17.0

Radhapuram channel - 6469.63.5 409.77.5 6879.41

Total 7396.36.0 768.47.5 8164.83.0

III.

1.

N.P.Channel

L.S. 0 to 12000 m

Head - 542.24.0 664.05.0 1206.29.0

Total 542.24.0 664.05.0 1206.29.0

2. L.S. 12000 to 24563 m Middle - 669.72.0 1503.04.0 2172.76.0

Total 669.72.0 1503.04.0 2172.76.0

3.a MettuKal Tail - 149.39.0 486.23.5 635.62.5

b. Regulator Kal - - 344.13 344.13.0

Total 149.39.0 830.36.5

979.75.6

IV

1.

Pazhayar

1stAnicut to 5thAnicut

(Verapukianicut, Kuttyanicut,

Pallikondananicut,

Chattuputhooranicut,

Chettithoppuanicut)

Head - 769.62.5 197.44.0 967.06.5

Total 769.62.5 197.44.0 967.06.5

2. 6th Anicut to 8thAnicut

(Veerarayanamangalam,

Sabarianicut, Kumarianicut)

Middle - 2754.40.0 1698.01.0 4452.41.0

Total 2754.40.0 1698.01.0 4452.41.0

3. 9thAnicut to 11thAnicut

(Chollanthittaianicut, Pillaiparthananicut, Mission

Anicut)

Tail - 927.10.0 - 927.10.0

Total 927.10.0 - 927.10.0

The command area map of Kodaiyar river basin is shown in Fig.

Fig. Command area map of Kodaiyar river basin

Even though Kodaiyar basin is a small basin when compared to other basins of Tamilnadu,

the number of rainfed tanks in this basin is large and it is 1460.Out of the 1460 rainfed tanks, 55

tanks are maintained by PWD and the remaining 1405 tanks are maintained by the Panchayat

unions. Some of the tanks are like tiny ponds having ayacut even below 1 ha.Apart from this there

are 301 tanks with no ayacut. The total ayacut under minor Irrigation tanks maintained by

Panchayat Unions is 5180 ha. The details of tank under each taluks are given in Table-10.

Table-10: Taluk wise tank details of Kodaiyar basin

Sl. No. Name of Taluk No. of tanks

1 Vilavancode 922

2 Agastheeswaram 11

3 Kalkulam 436

4 Thovalai 91

Total 1460

Interbasin transfer of water - from Kodaiyar basin

1. Transfer through Thovalai Channel to Radhapuram canal under Hanumanadhi basin (tail

reach), There is transfer of water from Thovalai channel of Kodaiyar basin from its tail reach to

feed tail reach ayacut of Hanumanadhi sub basin of Kodaiyar Basin (But its ayacut is considered

under Kodaiyar main basin).

2. Transfer through Alathuraiyar to Hanumanadhi basin (head reach). There is transfer of water

from Alathuraiyar (a tributary of Pazhayar) to feed the head reach ayacut of Hanumanadhi sub

basin in Tirunelveli District.

Interbasin transfer of water - to Kodaiyar basin

Transfer through Madras main canal or Kanniyakumari canal. There is transfer of water

from Neyyar basin of Kerala state to Kodaiyar basin through Madras main canal.

Occurrence of groundwater in six sub basins of Kodaiyar River Basin

1. Valliyar Sub Basin

There are seven observation wells in this sub basin. The average winter water level varies

from 4.55m to 16.08m and the summer water level ranges from 6.63m to 19.75m below ground

level.

2. Perunchani Sub Basin

No observation well is present in this area, and there is no water demand for irrigation.

3. Pechiparai Sub Basin

No observation well exist in this sub-basin also. No details of bore well are also available

for this Sub-basin.

4. Pazhayar Sub Basin

This is the largest Sub-basin of Kodaiyar Basin.There are ten observation wells in this sub

basin. More depletion of Water is observed in Well No. 93054 owing to its proximity to Nagercoil

town. This well has been closed in the year 2009. In all other areas, the average winter water level

varies from 1.87m to 7.32m and the summer water level varies from 2.26m to 7.95m.

Radhapuram block is an over-exploited zone in this sub-basin.

5. Kuzhithuraiyar Sub Basin

This is the second largest Sub-basin of Kodaiyar Basin. There are four observation wells in

this sub basin. The winter water level varies from 6.50m to 13.58m and the summer water level

ranges from 7.21m to 14.13m below ground level.

6. Chittar Sub Basin

Two observation wells exist in this Sub-basin namely Well No.93035 (Kochuthuparai

Village of Tiruvattar block) and Well No.93047 (Mulucode Village of Melpuram block). The

winter water level ranges from 2.65m to 2.74m in the well No 93035 and the summer water level

ranges from 3.79m to 3.92m. With respect to well No 93047 the winter water level ranges from

9.67 m to 10.49 m and the summer water level ranges from 11.14 to 11.33 m below ground level.

The sharp variation of water levels may be due to the difference in elevation between them, MSL

of well No 93035 is +70.99m, MSL of well No 93047 is +92.92m.

Groundwater Potential in the Study Area

The total available groundwater potential as on March 2013 is worked out as 239.59 Mcum

and the is shown in Table 11.

Table 11 – Ground Water Potential Calculation as

Mar 2013

Name of

District

covered

Area

covered

in %

Net water

available

Ground

water

potential

District

wise

Kanyakumari 100.00 23958.61 23958.61

Total 23958.61 Ha.m

239.5861 M.cum

PRESENT AND FUTURE WATER DEMANDS

Domestic water demand

Projected domestic water demand is given in Table-13.

Year

Population Demand

MLD MCM

2010

Municipality 306989.00

120.99 44.16 Town

panchayat 897352.00

Rural 763659.00

2017


137.33 50.12 Town

panchayat 1030775.38

Rural 835921.69

2020


145.01 52.93 Town


Rural 868948.28

2030


173.94 63.49 Town


Rural 988754.29

2040


208.83 76.22 Town


Rural 1125078.53

Livestock Water Demand

The livestock water demand for Kodaiyar basin is presented in Table-14.

Table-14 Livestock Water Demand

Sl.

No. Name

Standard

Norms in

lpcd Demand

2017

Demand

2020

Demand

2030

Demand

2040

Demand

2050

1 Cattle 225 7.41 7.51 7.83 8.16 8.51

2 Buffalo 225 0.5 0.44 0.28 0.18 0.12

3 Bovine 100 3.58 3.58 3.58 3.58 3.58

4 Sheep 5 0.01 0.01 0.01 0.01 0.01

5 Goats 5 0.15 0.16 0.2 0.26 0.32

6 Ovine 110 2.32 2.32 2.32 2.32 2.32

7

Horses &

Ponies 100 0 0 0 0 0

8 Donkeys 25 0.001 0.001 0.001 0.001 0.001

9 Pigs 206 0.14 0.13 0.08 0.05 0.03

10 Dogs 20 0.377 0.377 0.377 0.377 0.377

11 Rabbits 10 0.001 0.001 0.001 0.001 0.001

12 Poultry 0.05 0.05 0.07 0.15 0.35 0.8

13 Duck 10 0.031 0.031 0.031 0.031 0.031

14 other birds 10 0.002 0.002 0.002 0.002 0.002

Total 14.572 14.599 14.829 15.289 16.069

Industrial water demand

At present in the Kodaiyar basin there are 44 numbers of large and medium industries and 1179 numbers of small scale industries. The norms for

water requirement as per the recommendations of industries department is 2500 Mcum / day / unit for large and medium industries and 2.5 Mcum /

day / unit for small scale industries. Accordingly, the yearly requirement of water for small scale industries during the year 2017 is calculated as 1.84

Mcum and for the large and medium scale industries is calculated as 68.44 Mcum. Hence, the total annual water requirement for industries in the

basin is 70.28 Mcum.

For forecasting the water demand of Industries for future years, a simple arithmetic increase of 8% per annum over the present requirement has been

adopted. The annual water demand for the Industries during the planning periods for each sub basin is given in Table-16.

Table-16: WATER DEMAND CALCULATION FOR SMALL, MEDIUM AND LARGE INDUSTRIES BASED ON INDUSTRY CENSUS AS TAKEN

FROM IWS

Sl.

No. Type of industry

Average

Rate of

Water

consumption

as given in

IWS

m3/day

2010 2017 2020 2030 2040 2050

No. of

industry

as per

IWS

Water

Demand

No. of

industry

Water

Demand

No. of

industry

Water

Demand

No. of

industry

Water

Demand

No. of

industry

Water

Demand

No. of

industry

Water

Demand

1 Small scale industry 2.5 1179 1.08 2021 1.84 2545 2.32 5495 5.01 11864 10.83 25613 23.37

2

Medium & large

scale industry 2500 44 40.15 75 68.44 95 86.69 205 187.06 443 404.24 956 872.35

Total Demand in

M.Cum 41.23 70.28 89.01 192.07 415.07 895.72

Power Generation (Hydro-Electric)

At present there are 2 Hydro power plants in Pechiparai Sub basin. The Kodaiyar power

house I is located below the upper Kodaiyar reservoir generating 60 MW power and the Kodaiyar

Power House II is located below the lower Kodaiyar reservoir generating 40 MW Power.

The Hydro power schemes proposed are:

1. Below Pechiparai Dam - 1.30 MW

2. Below Perunchani Dam - 1.30 MW

3. Paralayar above Perunchani Dam - 25 MW

One Atomic Power plant at Koodankulam in Tirunelveli district outside of this basin is

proposed considering to draw 10 MCM water from Perunchani dam by pipe line. The water

demand for power plant is given in Table-17 and the non water consumptive power plants are

given in Table-18.

Table-17: Power Plant Water Demand

Location

Inside / Outside

Power Plant Year Annual Demand

in MCM

Outside Koodankulam (Atomic) 2020 10.00

Outside Koodankulam (Atomic) 2045 10.00

Table-18: Non Water Consumptive Power Plants (Hydro)

Sub Basin Name of Power Plant Capacity (MW)

Existing

Pechiparai Kodaiyar Power House I 60

Kodaiyar Power House II 40

Proposed

Pechiparai Pechiparai Dam 1.3

Perunchani Perunchani Dam 1.3

Chittar Paralayar 25

The Hydropower plants are non water consumptive. However the Water required for

power generation are estimated assuming 2 MCM of water required per MW of power generation

in hilly area and 20 MCM per MW in Plain area.

WATER BALANCING

Water balancing for Kodaiyar river basin at 75% dependability which includes water potential, demand and deficitfor the projected years are

given in Table-.

Table-: Water Balancing for Kodaiyar River Basin at 75% dependability

Sl.

No

Name of

the basin

Area of the

basin

(in Sq.Km)

No. of

Sub

basins

Year

Total demand of water in various sectors Mcm Water availabilty in Mcm

Gap

Irrigation Domestics Industries Live

Stock Others Total

Surface

water

potential

Ground

water

potential

Quantity

of

recycled

water

from

Sewage

Quantity

of water

from

desilting

Total

1 Kodaiyar 1646.964 6

2010 728.00 44.16 41.23 0 813.39 916.00 239.59 --- 62.27 1217.86 404.46

2017 728.00 50.12 70.28 14.57 0 862.98 916.00 239.59 --- --- 1155.59 292.61

2020 728.00 52.93 89.01 14.60 0 884.54 916.00 239.59 --- --- 1155.59 271.05

2030 728.00 63.49 192.07 14.83 0 998.39 916.00 239.59 --- --- 1155.59 157.20

2040 728.00 76.22 415.07 15.29 0 1234.58 916.00 239.59 --- --- 1155.59 -79.00

one of the oldest systems in tamil nadu is the “kodaiyar

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