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Home , Bodinayakkanur, Cumbum Valley, Kadamalaigundu, Kottampatti block, Melur, Ramanathapuram

Vaigai Basin

Introduction

There are 34 river basins in . For hydrological studies, they are grouped into 17 river basins. The basin is one of them. Vaigai river basin covers an area of about 7009.13 sq.km and hilly area extends to 2,101.68 sq.km and located in the , Dindugal, , , and Districts of Tamil Nadu. Vaigai, the main river originating from Varushanadu valley with its tributaries forms a well-defined, compact drainage basin. It has a varied climatic condition resulting often in unreliable rainfall, drought prone, sudden floods, etc. This gives rise to unpredictable water resources condition but for the reservoir water flowing through this basin due to the construction of the Periyar trans-basin scheme which made it possible to divert water from the Periyar basin in the State of to Tamil Nadu.The index map of Vaigai River Basin is shown in figure 1.

Figure 1 Index Map of Vaigai River Basin Location and Extent Vaigai river basin lies between the geographic co-ordinates Lat. 9o 15’ – 10o 20’ N and Long. 77o 10’ - 79o 15’ and falls within the Survey of toposheets, 58F, 58G, 58J and 58k. The total extent of the area is covered within the administrative boundaries of 20 taluks and 37 blocks. Figure 2 shows the Administrative boundaries.

Figure 2 Administrative Map of Vaigai River Basin The Vagai basin is surrounded by Cauvery and Pambar Kottakaraiyar basins, on the north, Gundar basin, on the south, west by Periyar basin and east by . The length of the basin is about 289.59 km and the width varies from 15 to 55 km. The important urban settlements like Madurai, Cumbum, , , Theni, , Nilakottai, , , and Ramanathapuram are located in the study area. The basin is an arcuate in shape, stretching from the mountain of Kerala in the west to the Bay of Bengal on the east, with a general gradient towards North east, up to Theni and then south eastern direction up to the sea. The river basin is flanked by Western ghats on the south and west, southern slope of hills ( hills), Sirumalai hills, Alagar hills etc. on the north, and Bay of Bengal on the east. The relief Map of the Vaigai Basin is shown in Figure 3.

Figure 3 Relief Map of Vaigai River Basin Physiographical study of vaigai basin reveals that the basin area can be broadly classified into three units namely 1. Western mountainous terrain with valley complexes, 2.Central elevated terrain and 3. Eastern coastal plain. Drainage The river Vaigai originates in the eastern slope of the Western ghat mountainous offshoot in the Varushanad area and flows northwards through Gandamanayakkanur. The Suriliyar and Theniar join Vaigai near Kottapatti. There after Vaigai flows east and south east directions till it confluences with Bay of Bengal. Varattar, Nagalar, Varahanadhi, Manjalar, Marudhanadhi, Sirumaliar, Sathaiyar originate in and Sirumalai hills which are the main tributaries, joining Vaigai along its course. Uppar river originates in the Alagar hills and joins Vaigai near Manamadurai. Then Vaigai enters into the Ramnad big tank and the surplus only reaches the sea. The length of the Vaigai river upto Ramnad big tank is 266.71 km and Ramnad big tank to sea is 28.40 Km. Vaigai river and its tributaries are semi perennial to ephemeral in nature, and the flow in the Suriliyar and Vaigai is mainly due to the Periyar lake water diverted through Viravanar and then to Suriliyar during the monsoonal periods. Figure 4 Shows the drainage details of Vaigai Basin.

Figure 4 Drainage Map of Vaigai River Basin Based on the natural drainage pattern, the vaigai basin is divided into ten sub basins they are Upper Vaigai, Suriliyar, Theniar, Varattar - Nagalar, Varahanadhi, Manjalar - Marudhanadhi, Sirumalaiar, Sathaiyar, Uppar and Lower Vaigai basin. The areal extent of each sub basin, hills, plains etc. are given in the Table 1.

Table 1 Area and Percentage of Sub Basins in Vaigai Basin

Sl. Total area Hilly area Plain area Name of the sub basin Percentage Percentage No. in Ha. in Ha. in Ha. 1 Upper vaigai 822.02 558.97 67.99 263.05 32.01 2 Suriliyar 640.10 217.95 34.05 422.15 65.95 3 Theniyar 651.65 310.84 47.69 340.81 52.31 4 VarattarNagalar 631.82 231.31 36.62 400.51 63.38 5 Varahanadhi 380.28 200.65 52.75 179.65 47.25 6 Manjalar 612.74 309.68 50.54 303.06 49.46 7 Surumalaiyar 541.59 131.66 24.30 409.91 75.70 8 Sathiyar 782.76 119.29 15.24 663.45 84.76 9 Uppar 882.29 21.35 2.42 860.94 97.58 10 Lower Vaigai 1063.88 - - 1063.88 100.00 TOTAL 7009.13 2101.68 - 4907.43 -

Geology Vaigai river basin is covered by hard crystalline rock masses of Archaean age on the western portion; nearly 74% are sedimentary rocks of Upper Gondwana, Tertiary and quaternary age are on the eastern portion (26%). Aerial photographs and satellite data were also utilized in the demarcation of the boundary conditions of various lithological units and to delineate structural features. Figure 5 shows the geologic formations in the Vaigai Basin.

Figure 5 Geology Map of Vaigai River Basin From Manamadurai to the Bay of Bengal, rocks of upper Gondwana, teritiary alluvium and coastal alluvium are spread over the Archaean formations unconformably. Aeolian sands are also found to occur in isolated pockets in the and coastal areas. Land Use Vaigai basin reappraisal study uses LISS IV Mx of IRS P6 satellite imagery of March 2009 for analysis of land use changes over a decade in Vaigai river basin. In the present study high resolution satellite imagery was used to classify the land use at micro level. Finally the interpreted land use themes were digitized using Geo media professional GIS software V5.2 and all the spatial data have been converted into vector format for GIS analysis. Figure 6 Shows the Land use Classification of the Vaigai Basin.

Figure 6 Land use Map of Vaigai River Basin The Land use category of Vaigai basin is shown in Table 2 Table 2 Vaigai Basin-Land Use Category Sl. Land use category Percentage Area in Sq.Km No I Level II Level % 1 Built up land Settlement 124.00 1.77 Wet crop land- Paddy, Sugar cane 1574.20 22.45 2 Crop land and banana. Dry crop land- Groundnut, ragi, 670.10 9.56 cholam, cumbu, maize, cereals, cotton, chilies, black gram, vegetables, floriculture etc. Grooves 115.00 1.63 3 Forest land Medium Dense forest 217.00 3.09 Dense forest and plantation 1324.50 18.89 Hills covered by shrubs/ scrubs 532.80 7.60 Reserved Forest 11.00 0.16 4 Waste land Barren land, Rocky out crop, stony 1636.00 23.33 waste Area affected by alkalinity/salinity 242.30 3.50 Land covered by shrub/ scrub 356.10 5.07 5 Water bodies Back swamp 25.10 0.36 Tanks 148.40 2.12 Reservoir 32.43 0.47 Total area 7009.13 100

Land use change detection The land use change detection study is analysed for the period of 2001 to 2009. The land use study reflects that the following category have increased in its extent i.e built-up land 82.76 Sq.km i.e. 1.18%, dry crop land 202.50 Sq.km i.e. 2.86%, waste land 188.36 Sq.Km i.e. 2.60% and decreasing trend have also been observed especially in the category of crop land area 270 Sq.Km i.e. 3.86% which is mainly due to the depletion of water level found to occur in many parts of the basin area. A comparative statement is shown in the table 3.

Table 3 Comparison of Change in Land Use

Area in Land use category Area in Percenta Sl. Sq.Km Percenta Sq.Km ge No. As on ge % I Level II Level As on 2001 % 2009 1 Built up Settlement 41.24 0.59 124.00 1.77 land 2 Crop land Wet crop land- Paddy, Sugar cane and banana. Dry crop land- Groundnut, ragi, cholam, cumbu, maize, cereals, cotton, 2629.5 38.03 2359.30 33.64 chilies, black gram, red gram, vegetables, floriculture etc. Grooves

3 Forest Medium Dense forest land Dense forest and plantation Hills covered by shrubs/ scrubs Reserved Forest 2075.55 29.68 2085.30 29.74

4 Waste Barren land, Rocky out crop, land stony waste Area affected by 2049.04 29.30 2234.40 30.9 alkalinity/salinity Land covered by shrub/ scrub 5 Water Back swamp bodies Tanks 198.47 2.83 205.90 2.95 Reservoir Total area 7009.13 100

Geomorphology The different land forms of Vaigai Basin are shown in the figure 7.

Figure 7 Geomorphology Map of Vaigai River Basin Soils The Soils of Vaigai Basin is classified as Deep Red Soil, Red Soil, Red Sandy Soil, Black Clayey Soil, Laterite Soil and Alluvial Soil. Deep red soil is prevalent in cumbum valley near , Uttamapalayam and Cumbum areas. Between and Peranai red soil is prevalent. The soil is red to yellowish red and sometimes brownish in colour and has a thickness varying from 0.25m to 3m in this area. The Red Sandy soil is the soil mixed with sand or quartz fragments. These are found in the area in vicinity of quartzite outcrops. Black coloured, black to brownish soil is found in some part of this area near , Meenakshipuram in this basin area. Lateritic soil is distributed in Kodaikanal hills and slopes and North West of Manamadurai. Alluvial Soil occurs predominantly in lower Vaigai basin and along Vaigai river and its tributaries. The figure 8 shows the Soil Classification of Vaigai Basin.

Figure 8 Soil Map of Vaigai River Basin

Groundwater Potential Zonation

The ground water potential is very good in Cumbum valley area including Chinnamanur, Uthamapalayam and upto Theni. It is also observed near , , Achampatti, Melakkal, and Virattipathu. In coastal area, east of Ramnad and west of Mandapam the ground water potential is very good, but the quality of ground water is poor due to semi marine deposits and very near to coast. The ground water potential in south of Bodinaickanur, west of Melur, east of Viraganur regulator and up to Ramnad is good. In general majority of areas in Vaigai basin the ground water occurrence is moderate to poor.

Population Size: Urban and Rural The sub basin wise urban population of Vaigai Basin is 2.009 million and rural population is 2.781 million and total population of Vaigai Basin is 4.790 million as per projected population in 2011. The basin is divided into ten sub basins. Subbasin wise rural and urban population of male and female is given in Table 4

Table 4 Sub Basin Wise Male and Female Population in Vaigai Basin

Male Population in Female Population Sl. Name of the 2011 in 2011 Total No. Sub Basin Rural Urban Rural Urban

1 Lower Vaigai 196890 126555 206839 127097 657381 2 Manjalar 36495 24388 35708 24158 120749

3 Sathaiyar 168478 766567 165062 749810 1849917

4 Sirumalaiyar 142501 24860 137357 24309 329027

5 Suriliyar 68733 150658 67121 148836 435348

6 Theniyar 52268 95639 51314 95064 294285

7 Uppar 117696 64861 114326 62193 359076

8 Upper Vaigai 91049 21601 88399 21175 222224

9 Varahanadhi 42814 63886 40665 62338 209703

10 Varattar Nagalar 94450 63920 91343 62677 312391

TOTAL 1011375 1402936 998135 1377658 4790103

Population Density In Vagai basin, the population density is the highest in Sathaiyar sub basin (2364.71 persons per sq.km) and the lowest is at Manjalar sub basin (197.47 Persons per sq.km). The sub basin wise population density in the Vaigai River basin is given in the Table 5.

Table 5 Sub basin wise Population Density in Vaigai River Basin

Sl. Name of the Sub Area Total population in Density in No. basin (Sq.km) Million in 2011 Persons / Sq.Km

1 Lower Vaigai 1063.88 0.657 617.55 2 Manjalar 612.74 0.121 197.47 3 Sathaiyar 782.76 1.851 2364.71 4 Sirumalaiyar 541.59 0.329 607.47 5 Suriliyar 640.10 0.435 679.58 6 Theniyar 651.65 0.294 451.16 7 Uppar 882.29 0.359 406.90 8 Upper Vaigai 822.02 0.222 270.07 9 Varahanadhi 380.28 0.210 552.22 10 VarattarNagalar 631.82 0.312 493.81 Total 7009.13 4.790 683.39

Hydrometeorology Raingauge Stations Vaigai basin lies in Theni, , Madurai, Sivaganga and Ramanathapuram districts. There are 27 non-recording rain gauge stations in this basin. Based on the distribution of rainguage stations and the availability of data (min 30 years), 25 rain gauge stations having long-term records in the basin are considered for detailed analysis. The details of the rain gauge stations such as, their location, geographical coordinates and the study period are shown in Table 6. For the purpose of rainfall analysis, month is taken as a time step. Table 6 Geographical coordinates of rain gauge stations

Name of Raingauge S.No Taluk District Source Latitutde Longitude Station

Andipatti Dindigul Dindigul PWD 10°03'45" 77°59'00" 1

Bodinayakkanur Uttamapalayam Theni PWD 10°01'11" 77°19'40" 2

Chittampatti Melur Madurai PWD 09°59'50" 78°16'36" 3

Cholavandhan Vadippatti Madurai PWD 10°01'20" 77°57'49" 4

Gudalur Uttamapalayam Theni PWD 09°40'48" 77°14'07" 5

Idayapatti Madurai North Madurai PWD 09°46'30" 78°16'15" 6

Kallandiri Madurai North Madurai PWD 10°02'10" 78°12'10" 7

Madurai Madurai North Madurai PWD 09°56'26" 78°07'58" 8

Manamadurai Sivagangai Sivagangai PWD 09°41'44" 78°27'30" 9

Manjalar Dam Theni Theni PWD 10°11'23" 77°37'56" 10

Melur Melur Madurai PWD 10°01'44" 78°20'04" 11

Mettupatti Vadippatti Madurai PWD 10°02'48" 78°06'56" 12

Nilakaottai Nilakottai Dindigul PWD 10°09'45" 77°51'15" 13 Ramanathapu Paramakudi Ramanathapuram PWD 09°32'51" 78°35'21" 14 ram

Peranai Nilakottai Dindigul PWD 10°05'20" 77°51'30" 15

Periyakulam Periakulam Theni PWD 10°07'31" 77°32'03" 16 Periyar Kerala State PWD 09°34'50" 77°10'44" 17

Pulipatti Melur Madurai PWD 10°05'10" 78°17'30" 18 Ramanathapu Ramanadhapuram Ramanathapuram PWD 09°22'15" 78°49'50" 19 ram

Sivagangai Sivagangai Sivagangai PWD 09°51'20" 78°29'14" 20

Thekkady Kerala State PWD 09°35'54" 77°10'23" 21

Uthamapalayam Uttamapalayam Theni PWD 09°48'05" 77°19'42" 22

Vaigai Dam Andipatti Theni PWD 10°03'05" 77°35'45" 23

Veerapandi Periakulam Theni PWD 09°57'45" 77°26'09" 24

Viralipatti Nilakottai Dindigul PWD 10°06'25" 77°43'35" 25

Monsoon and non-monsoon periods Vaigai river basin lies within the tropical monsoon zone. Based on the hydro-meteorological features of the basin, year is divided into two periods (i.e.) 1) Monsoon period spanning from June to December and 2) Non-monsoon period spanning from January to May. The monsoon period is further sub-divided into Southwest monsoon period spanning from June to September (4 months) and Northeast monsoon period spanning from October to December (3 months). Similarly, the non- monsoon period is further sub-divided into Winter period spanning from January & February (2 months) and Summer period spanning from March to May (3 months). The sum of all the seasonal rainfall gives the annual rainfall. As the monsoon period brings heavy rainfall, it improves the recharging of groundwater as well as storage of surface water. Hence, the monsoon period is hydrologically significant for water resources analysis. But in the case of non-monsoon period, the rainfall is insignificant. The details of Annual dependable rainfall of each sub basin are given in the table 7. The average annual rainfall is worked out to be 775.19 mm Table 7 Annual dependable rainfall (in mm) Name of the Sl.No 25% 50% 75% 90% Sub-basin

1 Lower Vaigai 229.38 180.47 137.19 106.87

2 Manjalar 111.29 77.59 48.45 15.28

3 Sathaiyar 139.13 106.92 76.18 43.69

4 Sirumaliyar 105.95 86.70 65.25 41.37

5 Suriliyar 112.34 85.36 64.87 47.07 6 Theniyar 96.02 77.34 50.22 32.32

7 Uppar 160.61 119.38 93.01 70.38

8 Upper Vaigai 137.99 102.61 70.12 42.32

9 Varahanadhi 83.88 70.59 45.25 29.57

Varattar 10 107.25 87.24 56.59 40.75 Nagalar

Meteorological details of the Vaigai Basin is given in the Table 8 & 9 Table 8 Climatological Parameters

S. Climatological Parameter Viralipatti Parthibanur No

1 Average monthly temperature 33.47 34.44 Maximum. in. 0 Celsius 2 Average monthly temperature 24.99 25.09 Minimum. in. 0 Celsius 3 Average mean temperature in 0 Celsius 29.23 29.77

4 Average relative humidity in % 60.89 67.78

5 Average wind velocity in km/hour 7.45 4.16 6 Average Sunshine hours / day 6.58 5.87

7 Pan Evaporation in mm/month 218.78 153.25

Table 9 Maximum and Minimum of Mean temperature

Name of the Minimum in Maximum in Mean Climatological Station Mean Temperature Temperature 24.280 Celsius 36.460 Celsius Viralipatti (1973-2017) (January 1974) (Apr 2016) 24.570 Celsius 34.750 Celsius Parthibanur (1976-2017) (December 2013) (May 2017)

The monthly average maximum temperature of the Viralipatti station varies from 27.690 Celsius (December 1978) to 40.100 Celsius (April 2017). The monthly average maximum temperature of the Parthibanur station varies from 25.730 Celsius (November 2006) to 40.630 Celsius (April 2017). The monthly average minimum temperature of the Viralipatti stations varies from 17.410 Celsius (February 1976) to 7.310 Celsius (April 1975). The monthly average minimum temperature of the Parthibanur station varies from 18.150 Celsius (December 2013) to 30.340 Celsius (April 1998).

Eto values (mm/month) of FCS for Vaigai basin Name of the basin

& FCS

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Average Vaigai basin - 100 108 134 132 134 117 115 120 122 107 93. 90. 114 Parthiba .8 .6 .5 .0 .2 .6 .3 .3 .1 .9 9 2 .8 nur FCS

Vaigai basin - 104 110 137 139 139 116 113 120 120 112 97. 96. 117 Viralipa .2 .6 .6 .5 .5 .7 .2 .3 .9 .5 5 7 .4 tti FCS

Surface Water Potential

The Vaigai river has its origin in the eastern slopes of western ghats in Gandhamanayakkanur Zamin at an altitude of 1524 m. The river course follows the Cumbum valley and joins with Suruliyar before it reaches Vaigai dam. Periyar, Palar and Koraliar are its tributaries. Beyond Vaigai dam, it is more or less a plain deltaic region until it falls into the sea. The length of the Vaigai river from origin to Ramnad big tank is 266.71 km. and below Ramnad big tank upto sea is 28.40 km. Thus, the total length of the Vaigai river from its origin to sea is 295.11 Km. Figure shows the flow diagram of Periya Vaigai river system.

Suriliyar River Varushanadu Valley Periyar Reservoir

Power Cumbum Anicut 18th Channel House New Vairavan Anicut Vairavan Anicut Chinnamanur Anicut Payathevan Anicut Shanmuganadhi Reservoir Anicut Uthamuthu Anicut Vaigai River Uppukottai Anicut Markayan Kottai Anicut Seelayampatti Chattarapatti Anicut Kothur Anicut Palanichettipattipatti Anicut Upparpatti Anicut Veerapandi Anicut

Theniyar River

Amachiapuram Anicut

Vaigai Reserv oir

58 villages canal Sothuparai Reservoir Varahanadhi River Pickup Anicut

Varattar Nagalar or Direct Canal

Manjalar River

Link Canal Manjalar Reservoir

9 Anicuts

Marudhanadhi Reservoir Syphon

5 Anicuts Marudhanadhi River Peranai Regulator Sirumalaiyar Odai

Thirumangalam Sathaiyar Reservoir Main Canal (TMC) Sathaiyar River

5 Anic uts

Periyar Main Canal

Virahanur Regulator Uppar Riv er

Parthibanur Regulator Legend Ramnad Big Tank Reservoir Anicut Regulator Not to Scale

Bay of Bengal

Figure 9 Flow diagram of Periyar Vaigai system

There are eight Reservoirs in this basin. They are (1) Periyar Dam (2) Vaigai Dam (3) Manjalar Dam (4) Marudhanadhi Dam (5) Sathaiyar Dam (6) Sothupparai Dam (7) Shanmughanadhi Dam and (8) Sirumalaiyar Odai. There are about 1,411 tanks in Vaigai basin out of which 1049 are system tanks and 362 are non-system tanks. The total storage capacity of tanks in Vaigai basin is 507.78 Mcm and the registered ayacut is 75622.06 Ha. In addition to this there are 994 tanks located in Gundar and Pambar & Kottakaraiyar basin benefited by Vaigai system. The total storage capacity of tanks outside the Vaigai basin but receives supply thro’ Vaigai system is 224.30 Mcm and the ayacut benefited is 39817.07 Ha. There are 10 gauging stations in Vaigai river basin and all the ten gauging stations are maintained by PWD. They are given in Table 10 along with their sub-basins. Table 10 Anicut / Dams and Sub basins

Sl.N Anicut / Dam Sub-basin o.

1. Suruliyar upper anicut Suruliyar

Palanichettipattianicut 2. (the last anicut of Cumbum valley) Suruliyar

3. Vaigai dam VarattarNagalar

4. Manjalar dam Manjalar

5. Marudhanadhi dam Manjalar

6. Peranai regulator Sirumalaiyar

7. Virahanur regulator Sathaiyar

8. Parthibanur regulator Lower Vaigai

9. Sathaiyar dam and Sathaiyar

10. Ramnad big tank Lower Vaigai

Reservoirs There are eight reservoirs in this basin. Their names, storage capacity, ayacut and catchment area is given in Table 11.

Table 11 Reservoirs in Vaigai Basin

Water Year of Registered Catchment Sl.N Name of the Capacity spread constru- Ayacut in area in o. reservoir in Mcm area in ction Ha Sq.Km Sq.Km 1 Periyar 1895 443.56 84268.82 26.44 602.95

2 Vaigai 1959 194.78 55104.85 25.90 2253

3 Manjalar 1967 13.48 2128.45 1.969 119.10

4 Marudhanadhi 1979 5.34 2668.00 0.725 53.35 5 Sathaiyar 1965 1.59 606.97 9.35 91.71 6 Sothuparai 2001 2.83 1159.91 0.144 87.04

7 Shanmughanadhi 2004 2.25 663.96 0.346 25.86

8 SirumalaiyarOdai 2009 0.44 127.83 0.122 17.80

Total 664.27 146728.79 64.996 3250.81

Tanks There are about 1,411 tanks in Vaigai basin out of which 1049 are system tanks and 362 are non-system tanks. The total storage capacity of tanks in Vaigai basin is 514.37Mcum and the registered ayacut is 75622.64 Ha. In addition to this there are 994 tanks located in Gundar and Pambar & Kottakaraiyar basin benefited by Vaigai system. The total storage capacity of tanks outside the Vaigai basin but receives supply thro’ Vaigai system is 224.30Mcm and the ayacut benefited is 39817.07 Ha. Sub basin wise System and Non-system tanks, their total storage capacity and ayacut benefited are given in Table 12. Outflow to Sea The Vaigai basin receives maximum rainfall during Northeast Monsoon and therefore there is appreciable surplus to sea during Northeast Monsoon season. The surplus flow from Ramnad big tank is measured as the surplus outflow to sea. Year wise surplus flow to sea is given in Table. 4.4. 75% & 50% dependable flow is “0” Mcm whereas 25 % dependable flow has been worked as 143.74 Mcm. The 33 years average surplus flow to sea measured in this basin as 88.38 Mcm.

Table 12 Tanks in Vaigai River Basin

System tanks Non System tanks Total Registered Sl. No. Name of Sub basin Capacity Registered Capacity Capacity Registered No. No. ayacut in No. in Mm3 ayacut in Ha in Mm3 in Mm3 ayacut in Ha Ha 1 Suruliyar 36 8.86 1889.16 4 0.74 180.57 40 9.60 2069.73 2 Theniyar 0 0.00 0.00 32 6.59 1703.61 32 6.59 1703.61 3 Varahanadhi 3 2.42 558.19 30 8.13 2089.80 33 10.55 2647.99 4 Varattar Nagalar 43 16.27 1985.01 17 4.68 606.04 60 20.94 2591.05 5 Upper Vaigai 0 0.00 0.00 13 2.40 531.74 13 2.40 531.74 6 Sirumalaiyar 23 19.99 3817.37 29 10.04 2253.97 52 30.03 6071.34 7 Manajalar 15 6.57 1176.15 11 1.78 886.18 26 8.35 2062.33 8 Sathaiyar 126 76.48 12744.10 62 6.10 1083.80 188 82.58 13827.90 9 Uppar 653 141.63 14466.70 129 44.18 7139.44 782 185.81 21606.14 10 Lower Vaigai 150 127.07 18662.04 35 30.45 3848.78 185 157.52 22510.82 I Total No. of tanks in 1049 399.29 55298.71 362 115.08 20323.92 1411 514.37 75622.64 Vaigai basin a Vaigai system tanks in 125 81.94 10811.62 0 0.00 0.00 125 81.94 10811.62 Gundar basin b Vaigai system tanks in 869 142.36 29005.45 0 0.00 0.00 869 142.36 29005.45 Pambar & Kottakaraiyar basin II Total No. of Vaigai 994 224.30 39817.07 0 0 0 994 224.30 39817.07 (a+b) system tanks outside Vaigai basin I+II Grand Total 2043 623.59 95115.78 362 115.08 20323.92 2405 738.67 115439.70 Surface Water Potential Assessment The Surface Water Potential is assessed by using Monthly Runoff Simulation Model. The Surface Water Potential is worked out for the 75% Dependable yield for South West, North East and Non Monsoon periods. The influencing stations in the subbasin are given in Table 13. Table 13 Rainfall Stations used in MRS Model Sl. Area Rainfall Station and Share in the basin Name of Sub-basins No. (Km2) area.

1. 822.02 Uthamapalayam, Veerapandi Upper Vaigai , Gudalur, Periyar, 2. Suruliyar 640.10 Uthamapalayam, Veerapandi

3. Theniyar 651.65 Bodinaikkanur

4. Varattar Nagalar 631.82 Vaigai Dam, Viralipatti

5. Varahanadhi 380.28 Periyakulam

6. Manjalar 612.74 Manjalar Dam

Nilakottai, Cholavandan, 7. Sirumalaiyar 541.59 Peranai, Andipatti

8. Sathaiyar 782.76 Mettupatti, Kallandiri, Madurai, Idayapatti

9. Uppar 882.29 Pulipatti, Melur, Chittampatti, Sivagangai

Manamadurai, Paramakudi, 10. Lower Vaigai 1063.88 Ramanathapuram

7009.13 Total

75% Dependable Surface Water Potential for each Subbasin of the Vaigai Basin shown in the Table 14. Table 14 75% Dependable Surface Water Potential for the Vaigai River Basin 75% Dependable Surface Water Potential Sl. in Mcm No. Name of Sub basin SW NE NM Annual

1. Upper Vaigai 16.02 35.16 18.94 70.12

2. Suruliyar 8.82 39.35 16.70 64.87

3. Theniar 13.78 27.59 8.85 50.22

4. Varattar Nagalar 12.07 32.91 11.61 56.59

5. Varahanadhi 7.00 26.43 11.83 45.25

6. Manjalar 14.06 17.75 16.64 48.45

7. Sirumalaiar 17.39 32.59 15.26 65.25

8. Sathaiyar 25.83 30.16 20.19 76.18

9. Uppar 25.83 50.63 16.54 93.01

10. Lower Vaigai 22.84 83.75 30.61 137.19

Vaigai Basin as a Whole 163.64 376.32 167.17 707.13

South West Monsoon 163.64 (or) 164 Mcm Potential 376.32 (or) 376 Mcm North East Monsoon 167.17 (or) 167 Mcm Potential 707.13 (or) 707 Mcm Non Monsoon Potential

Annual Potential

Total Surface Water Potential in Vaigai Basin:

1. Vaigai basin - Surface Water Potential from its own catchment = 707 Mcm

2. Periyar release to Vaigai basin (75% Dependability) (1970-2010)= 529 Mcm

Total Surface Water Potential at 75% Dependability = 1236 Mcm Total Surface Water Potential available including Periyar Release contribution is 1236 Mcm. Comparison of the present results with the earlier study results: The surface water potential assessment made by this Institute in the earlier Micro Level Study in the Vaigai basin during 2003 is given below in Table 15 for comparing the values with the present assessment. It is seen that the surface water potential derived from its own catchments has been reduced due to decline in annual rainfall pattern. Table 15 Comparison of Surface Water Potential in the years 2003 & 2011

Sl. 75% Dependable Surface Water Potential in Mcm Name of Sub basin No. 2003 2011 2017

1. Upper Vaigai 149.12 112.83 70.12

2. Suruliyar 80.85 94.91 64.87

3. Theniar 43.42 74.72 50.22

4. VarattarNagalar 74.16 81.46 56.59 5. Varaghanadhi 72.48 74.48 45.25

6. Manjalar 63.89 61.26 48.45

7. Sirumalaiar 47.15 48.59 65.25

8. Sathaiyar 94.66 66.26 76.18

9. Uppar 114.44 104.13 93.01

10. Lower Vaigai 161.13 123.05 137.19 Total Surface Water 11. 901.30 841.68 Potential Periyar Release to Tamil 12. 580 529 Nadu in Mcm

Inter basin transfer 1. Trasnsfer of water from Periyar Basin to Vaigai basin through a masonry gravity dam and a tunnel of 1740 m long with a discharging capacity of 40.75 cumecs to irrigate 84268.82 Ha. There is also a power station of 140 MW capacity. 2. Transfer of water from Vaigai to Guntar Basin to irrigate 4015.60 Hectares located in Madurai, districts. 3. Diversion of Surplus flood flow from Vaigair river Basin to virudhanagar and Upper Guntarsubbasin. 4. From Vaigai basin to Pamabar and Kottakarayar Basin

Ground Water Potential In the Vaigai Basin, groundwater occurs under water table condition and also under leaky conditions with water from one aquifer flowing vertically into another. The appraisal of groundwater occurrence is based on geological evaluation and on observation wells . An inventory of about 52 observation wells spread over the entire Vaigai Basin has been scrutinised and the periodical water level fluctuations were examined sub-basin and land classification wise, to understand the hydrogeological nature and groundwater occurrence. The appraisal of Ground water occurrence is based on the analysis of lithological log data of the observation wells and other deep bore wells along with the water level fluctuation data of the shallow observation wells and of the deeper bore wells. In Hard Rocks In the hard rocks the ground water occurs under water table conditions in the top loose formations and weathered zones. It occurs under semi-confined conditions in the fractured and fissured zones at deeper depths. Water-bearing zones are present in the formations with a cumulative thickness ranging from 1 m to 21 m. In Valley fill The Valley fill sediments are distributed in the Valley portions of Cumbum, , and Palakombai areas in the western part of Vaigai river basin. Ground water occurs under water table condition in general but semi confined condition has been observed in clay and silt formations. In Alluvium In the alluvial patch, the ground water occurs under water table conditions as well as in the semi-confined conditions. The alluvium is highly porous and permeable, developing into potential zones. In Sedimentary rocks The sedimentary formations encountered in this basin area includes upper gondwana, shale, grit, tertiary formations of sandstone and shale with recent to sub recent laterite and alluvium as the top layer in general. Ground water occurs under pheratic conditions in the upper portions and under semi confined conditions in the lower strata. The subbasin wise ground water fluctuations are shown below in the Table 16. Table 16 Sub Basin-wise Fluctuations Highest fluctuation S. Name of Sub (Seasonal) No. Basin Minimum During Maximum During in m the year in m the year 1 Lower Vaigai 2.47 93-94 7.38 04-05 2 Manjalar 3.05 02-03 21.70 10-11 3 Sathaiyar 4.02 01-02 7.95 01-02 4 Sirumalaiyar 3.95 98-99 7.65 93-94 5 Suruliyar 3.40 84-85 9.50 89-90 6 Theniyar 6.58 03-04 7.53 75-76 7 Uppar 3.80 97-98 8.50 94-95 8 Upper Vaigai 6.49 87-88 16.23 06-07 9 Varahanadhi 6.30 94-95 9.20 73-74 10 VarattarNagalar 8.10 77-78 22.80 10-11

The sub basin-wise groundwater potential and draft were calculated on pro-rata basis i.e based on the percentage of block area falling in the sub basin. The total ground water extraction of the basin is given in Table 17. Classification of the Blocks based on the level of Ground Water Development as on 2009 is shown in the Table 18. The balance groundwater potential available for further development was arrived by deducting the total groundwater extraction from the net groundwater recharge. The categorization of block is also presented it is understood that further groundwater development is possible in many blocks in Lower Vaigai, Sathaiyar, Uppar sub basins since many of the blocks in these sub basins were categorized as safe. In this study report, it was concluded that groundwater is the major source of irrigation in Lower Vaigai, Sathaiyar, Uppar sub basins, which indicates that groundwater development is already taking place in these three sub basins.

Surface Water Quality The main factors responsible for increasing water pollution are exponential growth of population, urbanization, industrialization and agricultural revolution. Even though Vaigai Basin consists of seasonal rivers, dumping of solid wastes of domestic and industrial origin in the river path would adversely affect the eco system. In the rainy season the water flowing in the river is affected by the solid wastes dumping in the river and causes floods in adjacent areas. Also during the rainy season the chemicals present in the solid wastes are dissolved in the rain water and carried by drains and streams which affect both surface and ground water quality. The perennial domestic sewage disposal into the rivers causes bad smell and creates many diseases in and around the location. In Vaigai Basin, surface water pollution occurs only around Madurai city because of letting in untreated domestic sewage, agricultural wastes and industrial effluents. In Nilakottai and Periyakulam taluks domestic pollution is more. The quality of water in Vaigai reservoir is good both for human consumption and irrigation use.

Table 17 Ground Water Potential Calculation as on Mar 2013 Ground Area water Name of District Net water covered potential covered available in % District wise

35.9 38685.27 13888.01

21.18 58016.67 12287.93

22.08 63797.96 14086.59

9.85 90618.63 8925.94 Sivagangai

10.99 51962.52 5710.68 Ramanathapuram

Total 54899.15 Ha.m 548.9915 M.cum

Table 18 Classification of the Blocks based on the level of Ground Water Development as on 2009

Sl. No. Name of Block District Level of Exploitation 1 Aathoor Over-exploited 2 Dindigul Over-exploited 3 Kodaikanal Safe 4 Natham Semi-critical Dindigul 5 Nilakottai Over-exploited 6 Reddiyarchatram Over-exploited 7 Sanarpatti Over-exploited 8 Vathalakundu Over-exploited 9 Alanganallur Semi-critical 10 Chellampatti Over-exploited 11 Kottampatti Safe 12 Madurai East Safe 13 Madurai West Safe Madurai 14 Melur Safe 15 Over-exploited 16 Semi-critical 17 Over-exploited 18 Safe 19 Bogalur Safe 20 Mandapam Safe 21 Nainarkoil Safe 22 Paramakudi Ramanathapuram Safe 23 Ramanathapuram Safe Thirupulani Poor quality 24 (Salinity) 25 Ilayankudi Safe 26 Kalayarkoil Safe Sivagangai 27 Manamadurai Safe 28 Sivagangai Safe 30 Andipatti Over-exploited 31 Bodinayakanur Critical 32 Chinnamanur Critical 33 Cumbam Critical Theni 34 K.Myladumparai Critical 35 Periyakulam Critical 36 Theni Critical 37 Uthamapalayam Over-exploited

Sedimentation in Reservoirs Sedimentation in each reservoir is shown in the following table 19, 20, 21 & 22 and the details of the sand quarries are given in the Table 23.

Table 19 Sedimentation in Vaigai Reservoir

Year Original Capacity Present Capacity Capacity Rate of (Mm3) Capacity (Mm3) Loss Loss Siltation (Mm3) %

1976 194.785 178.191 16.594 8.52 0.473

1981 194.785 172.439 22.346 11.47 0.499

1983 194.785 172.380 22.405 11.50 0.460

2000 194.785 167.21 27.575 14.16 0.337 Source: I.H.H Reports and Watershed management Board Division,

Table 20 Sedimentation in Marudhanadhi Reservoir

Original Capacity Present Loss of Capacity Percentage Year (Mm3) Capacity (Mm3) Capacity Loss Loss in (Mm3) % Capacity

1998 5.3377 5.2197 0.118 2.21 0.116

Source: I.H.H Report No.14/99

Table 21 Sedimentation in Manjalar Reservoir

Year Original Capacity Present Loss of Capacity Percentage (Mm3) Capacity (Mm3) Capacity Loss Loss in (Mm3) % Capacity

1992 13.7594 10.6316 3.1278 22.73 0.9092

1996 13.7594 10.3042 3.4548 25.109 0.8658

Source: I.H.H Report No. 4/96 and 4/97

Table 22 Sedimentation in Berijam Reservoir

Year Original Capacity Present Loss of Capacity Percentage (Mm3) Capacity (Mm3) Capacity Loss Loss in (Mm3) % Capacity

1987 2.19455 1.80442 0.39013 17.78 0.234

Table 23 Details of Sand Quarries Sl.No Name of Sand River Survey No. Possible Quantity to be Quarry quarried (m3)/ year 1 Soodiyur Vaigai 255 102480 (18100 Loads)

2 Vaigai 1-Jan 43500 (7685 loads)

3 Urapuli Vaigai 349 24000 (4240 loads)

4 Gangaikondan Vaigai 318, 107/1 120000 (21200 loads) 5 Oriyur Pambar 219 44500 (7862 loads)

6 Marungur Pambar 1 63500 (11200 loads)

Domestic water demand

Year Population Demand

Urban 2780000 2011 MLD MCM Rural 2010000

2011 Urban 2316523 241.139 119.42 (as given by local bodies) Rural 2151022 86.0409

Urban 2608781 272.277 2017 133.32 Rural 2324350 92.974

Urban 2768459 288.676 2020 140.64 Rural 2416183 96.6473

Urban 3374737 351.89 2030 168.58 Rural 2749314 109.973

Urban 4113785 428.96 2040 202.24 Rural 3128375 125.135 2050 Urban 5014681 522.9 242.83 Rural 3559699 142.388

Industrial water demand WATER DEMAND CALCULATION FOR SMALL, MEDIUM AND LARGE INDUSTRIES BASED ON INDUSTRY CENSUS AS TAKEN FROM IWS

Average 2014 2017 2020 2030 2040 2050 Rate of Sl. Type of Water No. of No. industry consumption industry as given in as per Water No. of Water No. of Water No. of Water No. of Water No. of Water IWS m3/day IWS Demand industry Demand industry Demand industry Demand industry Demand industry Demand Small scale 1 industry 2.5 67711 61.79 85296 77.83 107449 98.05 231974 211.68 500814 456.99 1081221 986.61 Medium & large scale 2 industry 2500 195 177.94 246 224.48 309 281.96 668 609.55 1442 1315.83 3114 2841.53 Total Demand in M.Cum 239.73 302.31 380.01 821.23 1772.82 3828.14

Water Balance Water balance for Vaigai basin at 75% dependability is shown in Table 28. Table 28 Water balance for Vaigai basin Demand of water in various sectors (MCM) Water availabilty (MCM) Area Quantit of the Quantit Remark Name No. of Surface Ground y of Sl. basin y of s-sewage of the Sub Year Irrigatio Domestic Industr Live Other water water recycled GAP No (in Total water Total MCM basin basins n s ies stocks s potentia potentia water Sq.Km from l l from ) desilting Effluent

2273.2 1952.0 - 0.08 2017 1802.00 133.32 302.31 35.57 0.00 1371.00 548.99 0.00 32.01 0 0 321.20 2358.3 1952.0 - 0.08 2020 1802.00 140.64 380.01 35.67 0.00 1371.00 548.99 0.00 32.01 2 0 406.32 VAIGA 1 6823 10 I 2828.2 1952.0 - 0.08 2030 1802.00 168.58 821.23 36.40 0.00 1371.00 548.99 0.00 32.01 1 0 876.21 - 3814.7 1952.0 0.08 2040 1802.00 202.24 1772.82 37.66 0.00 1371.00 548.99 0.00 32.01 1862.7 2 0 2