District Survey Report for Sand Mining Namakkal District 2019

Home , Kallanai Dam, Mallasamudram, Mandalam, Mayanur (Tamil Nadu), Namakkal, Namakkal district

DISTRICT SURVEY REPORT FOR SAND MINING NAMAKKAL DISTRICT 2019

SALEM DISTRICT

COtlCHirTIPALAYANERODE DISTRICT DIVISION

^KU I^TR A PAL^Vlf^ffALUW.

SC-KOUI MflCA'l^TAttlK' ^ x vc ERODE DISTRICT ERODE DIVISION yt NAMAKK PAMAUOAtAMmKUK

r PARAMATHI VELUR TAiOKl

KARURuiuioiywoii DISTRICT

INDEX

DISTRICT SURVEY REPORT-NAMAKKAL

S. No. Particulars Page no 1. Preface 1 2. Introduction 3 2.a Demographics 5 2.b Transport and Communication 5 3. General profile of the District 6 3.a Administrative structure 6 3.b Physiography 8 3.c Geology 9 4. River system- Cauvery 13 4.a Cauvery River 13 4.b Tirumanimuthar 15 4.c Sweta Nadhi 17 4.d Karaipottanar 18 5. Climate Characteristics, humidity and wind 19 5.a Climograph of Namakkal District 20 5.b Temperature graph of Namakkal 20 5.c Rainfall 21 5.d Humidity 21 5.e Wind 23 6. Land Utilisation pattern 25 6.a Soil 26 7. Processes of deposition of Sediments in the rivers of the District 27 8. Methodology and Guiding principles 29 8.a Method for calculation of reserves 32 9. Overview of mining activities in the District 33 10. Sand mining in the District - Details of production of sand, Revenue from the sand quarry wise of the District for the last 3 years Quarry wise sand sale and revenue details of Namakkal District for the year 2017-18 34 11. Quarry wise sand sale and revenue details of Namakkal District for the 38 year 2016-2017 12. Quarry wise sand sale and revenue details of Namakkal District for the 42 year 2015-2016 13. Process of Aggradation or Deposition of sediments in the River Cauvery 46 and Coleroon of Trichy District. 13.a Cauvery River Line diagram 48 13.b Cauvery in Tamil Nadu 49 13.c Location Map of Important Anicuts 50 13.d Delta Map of Cauvery 50 13.e Rainfall Pattern along Cauvery basin 51 13.f Geology along Cauvery basin map 52 13.g Shoaling in River bed 53 13.h Reduction of River carrying capacity by shoal formation 53 13.i Siltation problems U/S of anicut 54 13.j Delta of Cauvery Picture 54 14. Details of Field Data 56 14.a Location of CWC gauging site map 56 14.b Calibration study result using HECRAS diagram 57 14.c Location of Mayanur site map 57 14.d Field observations at M.puthur diagram 58 14.e Flow details 1973-2013 diagram 58 14.f Flow details 2013-2014 diagram 59 15. Estimation of sediments 59 15.a Flow regimes pictures 60 15.b Typical HECRAS results with cross section diagram 63 15.c Monthly flow over a decade diagram 65 15.d Sediment depth formation in Cauvery diagram 70 16. Drainage system with description of main rivers 72 17. Salient features of important rivers and streams 72 18. Mineral potential of the District 73 19. Economic impact of mining 74 20. Conclusion/ Recommendation 74

DISTRICT SURVEY REPORT FOR SAND MINING

NAMAKKAL DISTRICT

1. PREFACE

In compliance to the Notification issued by the Ministry of Environment and Forest and Climate Change dated 15-01-2016, the District Survey Report of river sand mining for Namakkal District is prepared. Every effort have been made to cover sand mining locations, areas and overview of mining activity in the District with all its relevant features pertaining to geology and mineral wealth in replenishable and non-replenishable areas of rivers, stream and other sand sources. This report will be a model and guiding document which is a compendium of available mineral resources, geographical setup, environmental and ecological setup of the District and is based on data of various departments, study conducted by renowned institutions, published reports and websites.

SURVEY REPORT OF NAMAKKAL DISTRICT

As per Gazette Notification of 15th January 2016 of Ministry of Environment, Forest and Climate Change, a survey shall be carried out by the District Environment Impact Assessment Authority (DEIAA) with assistance of Water Resources Department, Forest Department, Geology and Mining Department and Revenue Department in the District for preparation for District Survey Report as per sustainable sand mining guidelines to ensure identification of areas of aggradation or deposition where mining can be allowed and identification of areas of erosion and proximity to infrastructural structures and installations where mining should be prohibited and calculation of annual rate of replenishment and allowing time for replenishment after mining in that area.

The detailed study has been made through IIT, Madras to cover sand mining locations, area and overview of mining activity in the District with all its relevant features pertaining to geology and mineral wealth, replenishable and non-replenishable areas of rivers, stream and other sand sources. The mineral potential is calculated based on field investigation and geology of the catchment area of the river (or) streams. The area for removal of the mineral in a river or stream is decided depending on geomorphology and other factors. The District Survey Report shall form the basis for application for Environmental Clearance, preparation of reports and appraisal of projects. The report shall be updated once in five years.

2. INTRODUCTION:

Namakkal District is an inland District bounded by Salem District on the north, Karur District on the south, Trichirappalli District on the east and Erode District on the west. It has a total area of 3,49,671 hectares. It lies in between 11° 0’ and 12° 0’ north latitude and 77° 40’ and 78° 5’ east longitude.

W-^-E

MODE DISTRICT KUMAR APAM

WODE.

ERODE DISTRICT

Namakkal District holds Nature's beauty, historical temples, famous rock fort and hill station i.e. Kolli Hill . The Namakkal town is the District Headquarters and known as the "Egg City" as it contains a number of poultry farms. It finds a place in the map of India for its lorry building industry hence called as “Transport City”.

Agriculture, micro to mesoscale industry and Trade play vital role for its economic growth. Principal crops like tapioca, paddy, sugarcane, cotton, coconut, groundnut and various kinds of fruits and vegetables viz. horse gram, turmeric, mango, banana, and gingili are being cultivated in this District. Sago and Starch production in Rasipuram Taluk are exported to other countries.

Cotton Spinning Mills and Paper Mills are the major industries in Tiruchengode Taluk. Handloom weaving and power looms are found in Rasipuram, Kumarapalayam and Tiruchengode taluk. Few sugar mills are located in Mohanur and Kumarapalayam Taluk.

The District is well known as an abode of several reputed educational institutions. It provides a platform for schooling as well as higher education. As per 2011 census the average literacy rate in the District is 74.63% whereas 82.64% for males and 66.57% for females.

The District has several centres of attraction which allures many travellers from local areas and also different parts of the country. Namakkal is also called as “Namagiri”, the name of the rock formation at the center of the town. The Rock Fort in Namakkal is a special feature of the Town. The Fort covers an area of one and half acres of flat surface and is accessible from South-West by a flight of narrow steps. Namakkal is famous because of Sri Namagiri Thayar’s merciness, the greatness of Lakshmi Narasimha cave temple and the greatness of Lord Hanuman. The name Namakkal immediately brings to mind “Namakkal Anjaneya” – the temple of Hanuman at Namakkal. Namakkal is famous for a life-size Hanuman (Anjaneyar) Statue carved out of a single stone in the Anjeneyar Temple. The idol of Hanuman is approx. 18 feet in height, and stands under open sky. It is believed that the Hanuman statue keeps growing and to stop the growth a priest put a magic needle at the top of the statue’s head. The Narasimma Samy Temple along with Amman Temple is situated behind the Rock Fort in the heart of the town. The famous Tamil Poet “Namakkal Kavingnar Ramalingam Pillai” was born in this District. In the memory of the poet, State government has established an arts and science college for women in this District.

2.a DEMOGRAPHICS

According to 2011 census, Namakkal District had a population of 1,726,601 with a sex-ratio of 986 females for every 1,000 males, much above the national average of 929. A total of 150,699 were under the age of six, constituting 78,754 males and 71,945 females. Scheduled Castes and Scheduled Tribes accounted for 20% and 3.3% of the population respectively. The average literacy of the District was 68.12%, compared to the national average of 72.99%. The District had a total of 475,511 households. There were a total of 898,245 workers, comprising 152,497 cultivators, 228,614 main agricultural labourers, 35,156 in house hold industries, 422,885 other workers, 59,093 marginal workers, 5,976 marginal cultivators, 25,112 marginal agricultural labourers, 3,641 marginal workers in household industries and 24,364 other marginal workers.

2.b Transport and Communication

The District is well connected by both rail and road transports. The broad gauge line of southern railway can be approached from Salem, Mangalore, Thiruvananthapuram, Bangalore, Chennai, Mumbai and Delhi. Namakkal is connected to the rest of India through National Highway 44 (Asian Highway 43). Other towns and most of the villages are connected by road including State Highways and major District Roads.

NAMAKKAL DISTRICT Salem ^ ^VenrUmdur^

:Xtellasamudf^n \\ \ # Namagiripettai ■ Rasipuram f--.: " -Belukurichl Elachipalalaye yam NH-44 | , I'allip Tiruchengodu # Kalapfjf'anaickenpalli

, a Senthamangalam v Velagoundanpatty # Kalangani • - •Nailur valavantrl Nadu NAMAKKAL allampally Erode I # Poll i redd i patty LEGEND Erjmaippati® Varagu^ National Highway . Jedarpalaiyam pAvjtram Major Road Pottanui Padamudipaliyan #Valaiyapatti - - - Railway ' Tiruchchirapalll Distncl Boundary Stale Boundary River v ® Distncl HQ > Map not to Scale • Other Town Karur ■ Major Town yright © 2017 www.mapsofindia.com

3. GENERAL PROFILE OF THE DISTRICT

Namakkal District is a newly formed District from Salem District. It is functioning from 01-01-1997. It consists of 8 Taluks namely Namakkal, Rasipuram, Tiruchengode , Paramathi Velur, KolliHills, Sendamangalam, Komarapalayam and Mohanur. The District is bounded by Salem on the north, Karur on the south, Trichy and Salem on the east and Erode on the West. The Geographical area of the District is 3368.21 Sq.Kms. Which lies between 11.00 and 11.360 North Latitute and 77.280 and 78.300 East Longitude.

After the struggle between the Cheras, Cholas and Pandiyas, the Hoysalas rose to power and had control till the 14th Century followed by Vijayanagar Kings till 1565 A.D. Then the Madurai Nayakas came to power in 1623 A.D. Two of the Poligars of Thirumalai Nayak namely, Ramachandra Nayaka and Gatti Mudaliars ruled the Salem area. The Namakkal Fort is reported to have been built by Ramachandra Nayakas. After about 1625 A.D., the area came successively under the rule of Muslim Sultans of Bijapur and Golkonda, Mysore kings and then the Marattas. During 1750 A.D., Hyder Ali came to power. During this period, it was a history of power struggle between Hyder Ali and Tippu, with the British in1768.

Namakkal was under the rule of Atikula King called Gunasila who married to a Pallava King. Later on, it was overrun by the Cholas in the Kongu Mandalam which was again over run by the Cholas in the 9th Century and passed on to Vijayanagar under the Viuroyultry of Madura. Namakkal was held by Killdhar (Caption) of Hyder Ali until it was captured by British in Namakkal. Namakkal Distict was a part of Salem District until 1997. Namakkal is nearby Kolli hills and part of the Eastern Ghats. Kolli Hills is the most attractive destination in Namakkal District. Cauvery River flows through the Namakkal District.

3.a ADMINISTRATIVE STRUCTURE

Namakkal District includes 2 Revenue Divisions, 8 Taluks, 15 Community Division Blocks, 5 Municipalities and 19 Town Panchayats. The total number of Revenue Villages in the District is 391. There is one Parliamentary Constituency. There are 6 Assembly

Constituencies. One Assembly Constituency is reserved for Scheduled Castes and one for Scheduled Tribes.

NAMAKKAL DISTRICT REVENUE DIVISIONS

The District is divided into 2 Revenue divisions

1. Namakkal 2. Tiruchengode

NAMAKKAL DISTRICT SUB DIVISIONS (TALUKS)

1. Namakkal 4. Paramathivelur 7. Kumarapalayam

2. Rasipuram 5. Kolli hills 8. Mohanur

3. Tiruchengode 6. Sendamangalam

NAMAKKAL DISTRICT BLOCKS

1. Elachipalayam 6. Mohanur 11. Puduchatram

2. Erumapatty 7. Namagiripettai 12. Rasipuram

3. Kabilarmalai 8. Namakkal 13. Sendamangalam

4. KolliHills 9. Pallipalayam 14. Tiruchengode

5. Mallasamudram 10. Paramathy 15. Vennandur

MUNICIPALITY 1. Namakkal 3. Tiruchengode 5. Pallipalayam

2. Rasipuram 4. Kumarapalayam

TOWN PANCHAYATS

1. Aalampalayam 4. Namagiripettai 7. Pandamangalam

2. Mallasamudram 5. Padaveedu 8. Pothanur

3. Mohanur 6. Paramathy 9. Sendamangalam

10. Velur 14. Pattanam 18. Vengarai

11. Athanur 15. Pillanallur 19. R.Pudupatty

12. Erumapatty 16. Seerapalli

13. Kalappanaickenpatty 17. Vennandur

LOK SHABHA CONSTITUENCIES

Namakkal District Comes under 1 Lok Shabha Constituencies

1. Namakkal

ASSEMBLY CONSTITUENCIES

1. Rasipuram (SC) 3. Namakkal 5. Tiruchengode

2. Senthamangalam (ST) 4. Paramathi Velur 6. Komarapalayam 3.b PHYSIOGRAPHY

The District is generally a plain area with slightly undulating plains

PHYSIOGRAPHY NAMAKKAL DISTRICT SALEM ■■— fU) \ rmk

ERODE

TIRUCHIRAPPALLI

KARUR LEGEND District boundary 0-150 Metres Taluk boundary 150-300 Metres Rivers & Gully □ 300 - 600 Metres r~i 600 - Above

Bodomalai hills occupy the northern portion in 3 sets of hills namely Jeruga Thenmalai, Siddhamalai and Palamalai.

The plain area of the District can be divided into 3 elevating stages. The lower elevating below 150m has Namakkal, Patamathi Velur, Mohanur Taluk which are being benifited by Cauvery river. The mid elevation of 150-300m above M.S.L. occupies the major area in all taluks. The high elevated plain area lying between 300-600m is spread over minely in Rasipuram and Namakkal taluks.

The cauvery river flows along the western and southern boundaries of the District at an elevation of 150m. its tributaries are Sarabanga and Thirumanimuthar. Thus, Cauvery benefits Kabilarmalai and Mohanur blocks.

3.c GEOLOGY

The Geological formations of the District with predominant minerals found are tabulated below

GEOLOGY NAMAKKAL DISTRICT

SALEM •"l' ' i bc:./

S A G-? •>2f\ jr^~y /♦ S

ERODE

^ TIRUCHIRAPPALLI U5 KARUR REFERENCE LEGEND ALLUVIUM iO I BERYL District boundary (♦VXi CHARNOCK1TE iCsll CHROMITE |$t* | GRANITE AND SYENITE 1 I CORUNDUM Taluk boundary UNCLASSIFIED GNEISSES I dl'i FELSPAR Rivers & Gully pMs] MAGNETITE-QUARTZ1TE 1 % j IRON ORE 1=71 DOLARITE LS LIMESTONE [=71 DUNITE, PERIDOTITE \ 9 I MAGNES1TE [ (& | BAUXITE

S. No Name of Taluk Predominant Minerals

1 Namakkal, Charnokite, Iron ore, Magnesite, Magnetite, Limestone, Mohanur & Dolomite ParamathiVelur

2 Rasipuram Charnockite, Denterite, Iron ore.

3 Tiruchengode & Granite, Pyrite, Chromite, Feldspar, Limestone. Kumarapalayam

The Namakkal District is mostly underlain by the Archaean crystalline, metamorphic complex. The Geology of the District is complicated due to recurring tectonic and magmatic activities occurred during the pre-Cambrian period. The famous Sithampoondi complex known for its complex geology is situated in this District. There are four major groups of rocks in this District. They are 1. The older granulite group 2. The meta sedimentary group 3. The ultramafic and basic intrusives and 4.The younger pegmatoid granites. a) Gneisses: Gneisses are perhaps the oldest rocks in the District occurring widely in plains covering the four taluks. The general direction of foliation varies from EW to ENE-WSW with a high magnitude dip towards north or southeast. The gneisses are highly weathered upto 30m at some places, several ultramafic and basic rocks parallel to the foliation of the gneisses. b) Charnockites: The charnockites, coarse grained and bluish darkto grey in colour, have the second largest coverage in the District. They are exposed in the Kolli hills and Bodamalai hills. Some of them are garnetiferous and are massive and less weathered than the gneisses. They exhibit 2 to 3 distinct set of joints most of which are vertical, with steep dips.

These rocks occur in the Godumalai, Chitteri, Nainamalai and Valaiyapatti areas of the District. Iron ore deposits are associated with quartz felspathic gneiss, garnetiferous

quartz gneisses in Nainamalai area. These rocks are highly folded and jointed and less weathered. c) Calc-quatrzites and crystalline lime stones: These rocks are exposed in patches in Thiruchengode and namakkaltaluks. The thickness of the bands varies from a few metres to 10 m and the length extends to few kilometres. Their trend is in the NW-SE to NNW to SSE direction. d) Anorthosites and Pyroxenites: Massive and poorly jointed anorthosites bearing rocks are found near Sittampoondi complex. With a wide range of rocks associated with them are Chromite, pyroxenite, Anthophyllite, diopside, etc., e) Dolerite dykes and other intrusive: There are a number of basic intrusive dykes in Namakkaltaluk. They are massive running in NE-SW to NNE SSW direction, in general parallel to the foliation direction of the gneisses. They are few metres in thickness and a few kilometres in length. Their contact with country rock is sheared at many places. f) Granites and Syenites: These types of rocks are found in Thiruchengodetaluk. They are massive and jointed poorly. g) Laterites: The physical weathering and leaching in the flat topped hillocks of Kolli hills have given rise to laterites rich in alumina. There are also few pockets of bauxite in these hills. The weathering ranges from 10 to 15m. h) Alluvium and Talus: Thin Veneer of alluvium is found along the course of the Cauvery and Thirumanimuthar. However, alluvium of few metres thickness is found near the junction of the Thirumanimuthar with the river cauvery. The thickness of alluvium is 10-15 m in Paramathi – Velur area.

Talus consisting of cobbles and boulders is found at the foot hills of Kolli hills. Alluvium of 10 – 25 m thickness, which is important for groundwater development is found in the Nadukombai areas of Kolli hills. Several faults and shears occurring mostly with NE- SW trend, are expected to influence the course of groundwater movement, its storage and developmental potentials in the District

4.RIVER SYSTEM

4.a CAUVERY RIVER

7/, m f.' isZJ

ife''

.Jf

C, Emerald p> tauche^-..V P,PUlurT-* . ■ '

"1.1

The River Cauvery originates at Talakaveri in Coorg District of Karnataka in Brahmagiri Range of hills in the Western ghats at an elevation of 1341 m. (above MSL) and drains a total area of 81,155 Sq.Kms. of which 34,273 Sq.Kms lies in Karnataka, 43,856 Sq.Kms. in Tamil Nadu, 2,866 Sq.Kms. in Kerala and 160 Sq.Kms in Union Territory of Pondicherry. The Cauvery basin is bounded by Tungabhadra sub-basin of Krishna basin on the Northern side and Vaigai basin on the Southern side. The Western ghats form the Western boundary. The Nilgiris, an offshore of Western ghats, extend Eastwards to the Eastern ghats and divide the basin into two natural and political regions i.e., Karnataka plateau in the North and the Tamil Nadu plateau in the South. In Tamil Nadu, the Eastern part of the basin is in the elevation range of 0 to 150 m sloping gently up from the sea.

In the initial reaches of the Basin there are four important reservoirs namely 1) Harangi , 2) Hemavathi, 3) Kabini and 4) Krishnaraja Sagara. In the reaches downstream of Krishnaraja Sagara, at Shivanasamudram, the river branches off into two parts and falls through a height of 91 m. in a series of falls and rapids. The falls at this point is utilized for power generation. The power station at Shivanasamudram was built in as early as 1902. The two branches of the river join after the fall and flow through a wide gorge, which is known as "Mekedatu" (Goats leap) and continues its journey to form the boundary between Karnataka and Tamil Nadu States for a distance of 64 Kms. At Hogenakkal Falls, it takes southernly direction and enters the Mettur Reservoir which was constructed in 1934. A tributary called Bhavani joins Cauvery on the Right bank about 45 Kms below Mettur Reservoir. Thereafter it takes easternly course to enter the plains of Tamil Nadu. Two more tributaries Noyyal and Amaravathi join on the right bank and here the river widens with sandy bed and flows as "Akhanda Cauvery".

Immediately after crossing Tiruchirapalli District, the river divides into two parts, the Northern branch being called "The Coleroon" and Southern branch remains as Cauvery and from here the Cauvery Delta begins. After flowing for about 16 Kms, the two branches join again to form "Srirangam Island". On the Cauvery branch lies the “Grand Anicut” said to have been constructed by a Chola King in 2nd Century A.D. Below the Grand Anicut, the Cauvery branch splits into two, Cauvery and Vennar. These branches divide and sub-divide into small branches and form a network all over the delta. A brief description of the delta in the Karaikal region is given separately under para-1.2.1.The total length of the river from the origin to its outfall into the sea is 800 Kms. of which 320 Kms. is in Karnataka, 416 Kms. in Tamil Nadu and 64 Kms. forms the common border between the Karnataka and Tamil Nadu states. The Cauvery basin is fan shaped in Karnataka and leaf shaped in Tamil Nadu. The run-off does not drain off quickly because of its shape and therefore no fast rising floods occur in the basin.

CAUVERY BASIN MAP SHOWING SUB BASINS CAUVERY BASIN IN Sub Basin Wise Area in Sq Km SubBasin Area A 1. Chinnar 1749,77 2. Dodda Halla 835.887 1. Chinnar 3. Mettur Reservoir to Noyel confluence 5404.84 4. Palar Dodda Halla 1292.95 5. Moyar 2066.57 KARNATAKA PENNAIYAR BASIN 6. UpperBhavani 1806.91 Dodd 7. Lower Bhavani 2402.59 Legend Halla^ 8. Noyel 3535.82 ^ BASIN BOUNDARY 9. Tirumanimuttar 2476,96 10. Amaravathi 9253.53 SUB BASIN BOUNDARY 11. Karaipottanar 1001.37 12. Pungar (Upper Coleroon) 1308.7 3. Mettur 13. Aiyyar 1326.51 Reservoir 14. Ponnaniyar 1798.69 to Noyel 15. Nandiyar - Kulaiyar 1532.27 4. Pa ar Dodda Ha a confluence 16. Marudaiyar 877.162 17. Lower Coleroon 1500.56 5. Moyar 18. Cauvery Delta 7303.15 7. Lower Bhavani 9. Tirumanimu VELLAR BASIN UpperBhavani 17. Lower 13. Aiyyar Coleroon Noyel 16. Marudaivar 11. Karai pottanar 15. Nandiyar - Kulaiyar 12. Pungar PAP BASIN (Upper Coleroon)- 18. Cauvery Delta 10. Amaravathi 14. Ponnamyar

PAMBAR WATERGOVERNMENT RESOURCES OF DEPARTMENTTAMILNADU, KOTTAKARAIYAR INSTITUTE FOR WATER STUDIES .HYDROLOGY AND QUALITY CONTROL. VAIGAI BASIN BASIN TAMIL NADU STATETARAMANI CENTRE FOR , CHENNAI REMOTE 600 SENSING 113 APPLICATIONS 76°0'0"E 76°20'0"E 76o40,0"E 77°0,0"E

4.b THIRUMANIMUTHAR RIVER SUB BASIN:

Index Map of Thirumanimuthar Sub Basin River basins of Tamilnadu Andhra Pradesh

Pungaf/Upper

-r:- vaijsi

TAMIL NADU STATEGOVERNMENT CENTRE FOR OFREMOTE TAMIL NADUSENSING APPLICATION INSTITUTETHARAMANI,15 FOR WATER CHENNAI STUDIES, - 113. WRD.

Thirumanimuthar River is one of the tributary of River Cauvery. Thirumanimuthar river originating from Arunuthimalai Hills and Shevroy’s hills in the northern part of Salem District. It traverses through Valappadi, Yercaud, Salem, Rasipuram, Namakkal and Paramathivelur taluks in Salem and Namakkal Districts and Confluences with river Cauvery near Nanchai Idayar village in ParamathiVelur Taluk of Namakkal District. Total length of the river is about 105kms.

THiRWANIMUTMAR »4J0 OASIN ORAihiAOE MAP /5A

1.V «..►

10 (Km

There are 41 nos. of anicuts constructed across the river and are feeding 63 Nos. Tanks to irrigate an ayacut of 17,995 Acres.

4.c SWETHA NADHI SUB-BASIN

PONNAIYAR BASIN

SUB BASIN Ii ^1 Ii GomukhiUpper Vellar Nadhl CAUVERY BASIN iI 34 Ii LowerMani Mukta Vellar Nadhi ml s l AnaivariChinnar Odai lI ' Il BasinSweta BoundaryNadhi

Swetha Nadhi is tributary of Vellar River. Sweta Nadhi orginates at Kolli hills of Namakkal District and Patchimalai hills of Salem District. Total length of the river is 96Kilometre. The river Vellar is having 6 tributaries. They are 1.Anaimaduvu 2.Swethanadhi 3.Kallar 4.Chinnar 5.Manimukthanadhi 6.Gomukhi. A portion of Dharmapuri, Salem, Namakkal, Perambalur, Trichy, Villupuram and Cuddalore Districts are covered in Vellar river basin. Manimukthanadhi, which is the major tributary, also originates from Kalrayan hills in Villupuram District, traverses about 111 km and joins Vellar near Srimushnam in Chidambararm taluk of Cuddalore District. Upper Vellar drains the water from the southern slopes of the Kalrayan hills.

4.d Karaipottanar Sub Basin

Karaipottanar river is tributary of River Cauvery. Karaipottanar River originates from Kolli hills of Namakkal District. It confluences with Cauvery River at Kaduvetti village of Trichy District. Total length of the river is about 52km.

5. CLIMATIC CHARACTERISTICS

The District receives the rain under the influence of both southwest and northeast monsoons. The northeast monsoon chiefly contributes to the rainfall in the District. Most of the precipitation occurs in the form of cyclonic storms caused due to the depressions in Bay of Bengal. The southwest monsoon rainfall is highly erratic and summer rains are negligible.

Rainfall data from six stations over the period 1901-2000 were utilized and a perusal of the analysis shows that the normal annual rainfall over the District varies from about 640 mm to 880 mm. It is the minimum around Paramathi (640.50 mm) in the southwestern part of the District. It gradually increases towards north, northeast and east and attains a maximum around Rasipuram (880.5 mm) in the northern part.

The District enjoys a tropical climate. The weather is pleasant during the period from November to January. Mornings in general are more humid than the afternoons, with the humidity exceeding 78% on an average. In the period June to November the afternoon humidity exceeds 66% on an average. In the rest of the year the afternoons are drier, the summer afternoons being the driest.

The hot weather begins early in March, the highest temperature being felt in April and May. Weather cools down progressively from about the middle of June and by December, the mean daily maximum temperature drops to 30.2°C, while the mean daily minimum drops to 19.2°C and 19.6°C in January in Salem and Mettur Dam 7 respectively. Though the maximum temperatures in February are about the same as in July, the nights are much cooler in February. Being an interior District, the diurnal range of temperature is large, particularly in the dry and hot seasons. In February-March the mean diurnal range of temperature is as high as 13.7°C while in October-November it is only about 9°C.

5.a CLIMOGRAPH OF NAMAKKAL DISTRICT

Climate Summary

59% 7% precipitation: 5.0 In - - 0.3 in muggy; 98%

sweltering 4.0 beach/pool score; 7.3 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

5.b TEMPERATURE GRAPH

Average High and Low Temperature coo hot cool Apr 29 . 110 F Mar 16 c 100«F ^ 970F 100 F Jan 16 Oct 31 90oF 87 f 88F High SOT SOT yQ0F o 70 F 75 F 74T Low 680F 60oF SOT 40oF 30oF 20oF 10oF OT

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percenrile bands. The thin dolled lines are the corresponding average perceived temperatures.

5.c RAINFALL

Namakkal District generally experiences hot and dry climate. Hot weather in March and reaches maximum during April to between October to December. The average annual rainfall is 58 cm to 70cm, mainly during November.

Average Month rainfall 2011 2012 2013 2014 2015 2016 2017

January 1.31 0.8 0 0 0 24.9 0 6.58

February 3.34 5.6 0 14.2 0 3.44 0 0

March 16.35 2.6 0 1.9 0 2.56 0 19.17

April 54.13 146.3 41.4 27.4 14.4 105.42 7.74 24.12

May 89.07 68.6 40.2 29.4 97.6 78.29 74.57 98.59

June 22.75 12.7 4.2 44.4 27.5 45.89 23.84 8.21

July 36.82 42.9 52.8 12.8 32.2 25.19 106.4 -

August 99.74 101.6 52.4 123.4 69.2 58.8 44.24 -

September 84.37 50.4 78 104.7 99.3 165.41 28.11 -

October 149.4 149.1 164.1 112 207.9 129.66 22.34 -

November 123.5 123.7 52.4 65.5 44.5 175.57 6.26 -

December 35.76 18 0.6 16.6 8.4 28.27 23.76 -

Total 716.54 722.3 486.1 552.3 601 843.4 337.26 156.67

5.d HUMIDITY

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body.

Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies signicantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night. Nāmakkal experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 9.6 months, from March 16 to January 2, during which time the comfort level is muggy, oppressive, or miserable at least 57% of the time. The muggiest day of the year is October 5, with muggy conditions 98% of the time.

The least muggy day of the year is February 1, with muggy conditions 44% of the time.

5.d.1 Humidity Comfort Levels

muggy 100% dry 98% 90% Oct 5 comfortable 80%

70% humid Mar 1 muggy 60% 57% Feb 50% 44 40% 30% oppressive 20% 10% miserable 0% Jan Feb Mar Apr May Jun Jui Aug Sep Ocl Nov Dec Ory comfortable humid muggy oppressive miserable ssf tcf ut /of /if The percentage o! time spent at various humidity comfort levels, cdtegorl/ed by dew point.

5.e WIND

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and I stantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Nāmakkal experiences signicant seasonal variation over the course of the year.

The windier part of the year lasts for 3.3 months, from May 25 to September 4, with average wind speeds of more than 8.7 miles per hour. The windiest day of the year is June 30, with an average hourly wind speed of 12.1 miles per hour.

The calmer time of year lasts for 8.7 months, from September 4 to May 25. The calmest day of the year is October 22, with an average hourly wind speed of 5.3 miles per hour. 5.e.1 AVERAGE WIND SPEED DIAGRAM

Average Wind Speed windy 18 mph

16 mph

14 mph Jun 30 12.1 mph 12 mph May Sep 10 mph mph 8 mph Ocl 22 6 mph 3 m

4 mph

2 mph

0 mph Jan Feb Mar Apr May Jun Jul Aug Sep Ocl Nov Dec The average o! mean hourly wind speeds (dark gray line), with 2Sth to 7Slh and 10th to 90th percentile bands.

5.e.2 WIND DIRECTION DIAGRAM

E S W E 100% 0% north 80% 20%

60% 40% east west 40% 60%

20% soutbT 80%

0% 100% Jan Feb Mar Apr May Jun Jul Aug Sep Ocl Nov Dec

The percentage of hours m which the mean wind direction is from each of the four cardinal wind directions, excluding hours m which the mean wind speed ts less than 1.0 mph. The bghlfy tinted areas at the boundaries are the percentage of hours spent in the implied m termed tare directions (northeast southeast, southwest, and northwest).

6. LAND UTILISATION PATTERN

The land use pattern in the District is influenced by types of soil, groundwater, rainfall and irrigation projects. The major land use type in the area are barren land, crop land, dense forest and plantations, dry crop land, hill, shrub land, medium dense forest, reserved forest, and settlements. Around 22% of the total area is under irrigated cultivation, forest and barren land are 13% and 7.3% respectively.

Sl. No. Classification Year 2016-17 Year 2015-16 (1) (2) (3) (4)

1. Forest 1401.390 1401.390

2. Barren and Uncultivable uses 24454.355 24454.355

3. Land put to Non-Agricultural Uses 38787.015 38738.32

4. Cultivable Waste 4759.730 4759.730

5. Permanent Pastures and Other Grazing Land 6663.290 6663.290

6. Land Under Miscellaneous Tree Crops and 3767.74 3767.74 Groves not included in Net Area Sown

7. Current Fallows 65726.30 49130.620

8. Other Fallows Land 9321.455 9321.455

9. Net Area Sown 139330.555 155974.930

10. Geographical Area According to Village 294211.830 294211.830 Papers

11. Total Cropped Area 165910.085 207844.835

12. Area sown more than once 26579.525 51869.905

13. Reserve Forest 42507.602 42507.602

6.1. SOIL

Soil is one of the natural resources that impact the agricultural development of an area. The soils of Namakkal District can be broadly classified into 5 major soils types viz. Red Soil, Black Soil, Brown soil, Alluvial and Mixed Soil The major part of the area is characterised by red gravelly soil (in deeply buried pediments and moderately buried pediments) with red loamy soil. The red soils are medium to heavy textured soils with moderate to higher permeability. Red loamy soil is a product of weathered granite of Archaean age. The black soils are limited Namakkal taluk. They are fine textured with low permeability. The brown soils are limited to small part of Tiruchengode taluk and they characterised by low permeability. The alluvial soil (in the flood plains) is seen along the river courses in Namakkal, Moahanur, ParamathiVelur and Tiruchengode taluks. Mixed soil is the second major soil type occurring all the taluks of the District.

SOIL COLOUR N NAMAKKAL DISTRICT A Sl. Type of Soil Area (Sq. SALEM No km)

r vaVM /x,fWras,^^ , ) r.v /~o/ 1 Red Soil 2075.54

/. mr'O'M Hill Soi^ ^ /• 3 Black Soil 359.89 ERODE sM &rj AHAMATH1 ; ./JPiAMAKK/ 4 Alluvium 278.18 lV? ^ TIRUCHIRAPPALLI S ^ > KG 5 Mixed Soil 591.70 f? KARUR Total 3004.30 REFERENCE LEGEND District boundary RED SOIL Taluk boundary "~~] BLACK SOIL Rivers & Gully H BROWN SOIL ALLUVIAL SOIL

7. PROCESSES OF DEPOSITION OF SEDIMENTS IN THE RIVERS OF THE DISTRICT

River sediment refers to the mixture of mineral matters which are derived from the weathering and erosion of rocks present in the river bed. Sediments are derived by these natural processes and are subsequently transported by water and/or by the force of gravity acting on the sediments. Sediments become the river load and the river transport the sediments through its course. Transportation of the sediments depends on the energy of the river. Boulders are transported by traction and are rolled along the bed of the river. Slightly smaller particles, such as pebbles and gravel, are transported by saltation. This is where the load bounces along the bed of the river because the river has enough energy to lift the particles off the bed but the particles are too heavy to travel by suspension. Fine particles like clay and silt are transported in suspension. Most of the load is transported by suspension. Solution is a special method of transportation wherein soluble rocks such as limestone or chalk are transported in solution.

Deposition occurs when forces responsible for sediment transportation are no longer sufficient to overcome the forces of gravity and friction that create a resistance to motion. To transport the load, river needs energy while at the same time, when a river loses energy, it is forced to deposit its load.

Much of the material is carried in suspension and loads in suspension erode the river banks by abrasion. When rivers flow over flat land, they form large bends called meanders. As a river goes around a bend, most of the water is pushed towards the outside causing increased erosion. The river erodes sideways into its banks rather than downwards into its bed, a process called lateral erosion. On the inside of the bend, in contrast, there is much less water. The river will therefore be shallow and slow flowing. It cannot carry as much material and so sand and gravels will be deposited. This is called a point bar or slip off slope.

H.WJ h Culiide Carve Erosion I .'1 ll.p frcrtKrtVctecify OulslfleCurve Erosion

Outside Curve Erosicfl

» | tawdfttotfy

(MMeCuwl SlftSidfcCuwe Erojloji, position

IlKMUdyUK '■)] (kruvdiMocif/ t»ec<88^.'

Due to erosion on the outside of a bend and deposition on the inside, the shape of a meander will change over a period of time. Eventually deposition will block off the old meander to leave an oxbow lake. The oxbow lake will slowly dry up, only refilling after heavy rain or during a flood. The annual deposition in the river depends upon the velocity of the river, period of rainy season and rainfall at different places of the flow of rivers.

Satellite map of River Cauvery in Namakkal District

'udhupalayam

■Senapiratti

8. METHODOLOGY AND GUIDING PRINCIPLES

The trace of each and every river/ stream was covered and studied on the following principles of Geology/River bed mining:

 The general geology of the area;

 The presence of any major geological structure;

 Origin of river;

 Pattern of primary / secondary/ tertiary streams;

 Total catchments;

 General profile of river/streams;

 Meandering Pattern;

 Bank stability;

 Total potential of river bed in reference to minor mineral;

 General slope of the river / stream;

 Morphogenetic regions.

In Addition to above, presences of the following objects were also studied:-

 The presence of any WSS Schemes

 Bridges

 Agriculture fields

 Bank protection works

 Plantation etc.

Following are the important guiding principles considered while recommending the river / stream bed or part of the river / stream bed for collection for minor minerals:-

 The production of aggregate area is a function of the availability of natural resources, the size of population, the economy of the area and various developmental and infrastructural works being undertaken in the area like road construction, hydro- electric projects etc. Further, being a low- value, high-volume mineral commodity, the prices are dramatically affected by transportation distances. If the distance increases, the transportation cost may increase much more than the cost of the aggregates.

 A stable river is able to consistently transport the flow of sediments produced by watershed such that its dimension ( width and depth) pattern and vertical profile are maintained without aggrading ( building up) or degrading ( scouring down)

 The amount of boulders, cobbles, pebbles and sand deposited in river bed equals to the amount delivered to the river from watershed and from bank erosion minus amount transported downstream each year.

 It is compulsive nature for river to meander in their belts and therefore they will have to be provided with adequate corridor for meandering without hindrance. Any attempt to diminish the width of this corridor (floodway) and curb their freedom to meander would prove counterproductive.

 Erosion and deposition is law of nature. The river/stream has to complete its geomorphological cycle from youth, mature to old age.

 River capturing is unavoidable.

 Erosion in upstream and deposition in downstream.

 Tendency of the river / stream toward grade.

 Fundamentally, the lowest point of any stream is fixed by Sea Level.

 The ratio between the width of meander belt and width of the stream decreases as the width of the stream increases.

 Formation, Bank erosion and Replenishment of any specific riverbed depends Primarily upon:

 The Geology of the area;

 River Profile;

 Nature of source;

 Rainfall in catchments;

 Morphogenetic region;

 Catchments geomorphology;

 Efficiency of River / Stream ( i.e erosive power);

 The competency of the river / Stream ( i.e transport heaviest stone);

 The capacity of the River/Stream ( i.e volume of transportation);

 Hydraulic radius of the River / Stream (ratio between cross sectional area and length of wetted perimeter)

Secondarily upon:

 Geological structures;

 Porosity of formation;

 Run off in the catchments;

 Forest cover;

In addition to the above following man made factors are also involved.

 Type of agriculture;

 Encroachment on flood plain leaving least space for meandering;

 Any barrier on river / stream bed i.e banks , dams and bridge foundations etc;

 Throwing of debris into the river/stream course;

 Drying up of river courses due to construction of dams, thereby reducing the efficiency and capacity of the river / stream.

The total potential of the river / stream bed is calculated up to the depth of one meter and in the workable span. Total potential or annual replenishment is not necessarily mineable. Mine ability depends upon the availability of approachable roads, distance from the general conditions of policy viz distances from WSS Schemes, bridges etc and overall on the market demand etc. Thus keeping these factors into consideration 60% of the total potential has been taken for the purpose of exploitation of minor minerals.

8.1 METHOD FOR CALCULATION OF RESERVES:

For the calculation of total reserves of minor minerals available in the river bed, length, average width and depth of the river bed for which the exploitation is to be carried out / allowed under rule / prevailing instructions of the Govt. was taken into consideration. The volume thus obtained is multiplied with the bulk density which has been assumed as 1.65tonnes per cubic meter for all types of minor minerals. Thus reserves up to particular datum line i.e one meter below the surface have been calculated.

Total reserves of minor minerals ( M.T.)= Length x Width x Height i.e Depth x Density.

For the annual replenishment of minor mineral reserves, the average annual mean depth up to which the replenishment of minor mineral takes place annually, has been taken into consideration which depends upon the annual rainfall factor and geology of the catchments area.

9. OVERVIEW OF MINING ACTIVITIES IN THE DISTRICT.

Mineral of Economic importance found in Namakkal district of Tamil Nadu are mainly, limestone, magnesite, bauxite and quartz-feldspar. Limestone quarries are mainly located in Kumarapalayam, Tiruchengode and ParamathiVelur taluk while few leases for Bauxite are seen in and around Kolli Hill. Besides, the district is endowed with sizeable reserves of rough stone mainly in Senthamanglam, Tiruchengode, Namakkal and Rasipuram taluks.. High quality granite (both leuco and multi-coloured granite) is available in Paramathivelur taluk. Occurrence of good quality of Quartz and feldspar mining is situated Tiruchengode Taluk. Occurrence of PGE (Platinum Group of Elements) is reported in Sittampundi area, ParamathiVelur taluk. Brief details of mining activities in the district are tabulated below: The Department of Geology and Mining (DGM) is functioning in Namakkal district under the control of District Collector, Namakkal. The DGM is looking after the work of granting leases for minor minerals.

10. SAND MINING IN THE DISTRICT.

As per G.O.Ms No. 95 Industries (MMC-I) Department Dated 01.10.2003 The Public Works Department directly involves in sand mining operations in the State. .

10. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2017 - 2018

Apr-17 May-17 Jun-17

Sl Name of Quarry / Date of River Taluk No Village Commencement Total Amount No. of Total Amount No. of Total Amount No. of Loads (2 (Rs. In Days Loads (2 (Rs. In Days Loads (2 (Rs. In Days units) Lakhs) functioning units) Lakhs) functioning units) Lakhs) functioning

1 Kumarapalayam Cauvery Mohanur 26.11.2015 15730.58 132.14 375 ------

2 Oruvanthur Cauvery Mohanur 16.06.2017 ------

Total 15730.58 132.14 375 0.00 0.00 0 0.00 0.00 0

34 10. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2017 - 2018

Jul-17 Aug-17 Sep-17

1 Kumarapalayam Cauvery Mohanur 26.11.2015 ------97.28 0.82 11

2 Oruvanthur Cauvery Mohanur 16.06.2017 306.00 2.57 3 ------

Total 306.00 2.57 3 0.00 0.00 0 97.28 0.82 11

35 10. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2017 - 2018

Oct-17 Nov-17 Dec-17

1 Kumarapalayam Cauvery Mohanur 26.11.2015 268.20 2.25 25 435.15 3.66 23 368.78 3.10 17.00

2 Oruvanthur Cauvery Mohanur 16.06.2017 ------315.00 2.65 5.00

Total 268.20 2.25 25 435.15 3.66 23 683.78 5.74 22

36 10. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2017 - 2018

Total for the year 2017- Jan-18 Feb-18 Mar-18 2018 Sl Name of Quarry / Date of No. of No. of No. of No. of River Taluk Total Amount Total Amount Total Amount Total Amount No Village Commencement Days Days Days Days Loads (Rs. In Loads (Rs. In Loads (Rs. In Loads (2 (Rs. In function function function functio (2 units) Lakhs) (2 units) Lakhs) (2 units) Lakhs) units) Lakhs) ing ing ing ning

1 Kumarapalayam Cauvery Mohanur 26.11.2015 577.80 4.85 12 971.63 8.16 16 1233.00 10.36 18 19682.40 165.33 497

2 Oruvanthur Cauvery Mohanur 16.06.2017 ------621.00 5.22 8

Total 577.80 4.85 12 971.63 8.16 16 1233.00 10.36 18 20303.40 170.55 505

37 11. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2016 - 2017

Apr-16 May-16 Jun-16

1 Mohanur Cauvery Mohanur 01.09.2014 630.00 5.29 28 789.00 6.63 23 456.00 3.83 29

2 Kumarapalayam Cauvery Mohanur 26.11.2015 315.00 2.65 30 426.00 3.58 20 1350.00 11.34 29

3 Manapalli Cauvery Mohanur 27.02.2016 1395.00 11.72 30 513.00 4.31 20 651.00 5.47 29

Paramathi 4 Vengarai Cauvery 11.03.2013 726.00 6.10 30 273.00 2.29 12 velur

Total 3066.00 25.75 118 2001.00 16.81 75 2457.00 20.64 87

38 11. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2016 - 2017

Jul-16 Aug-16 Sep-16

1 Mohanur Cauvery Mohanur 01.09.2014 711.00 5.97 31 642.00 5.39 29 651.00 5.47 30

2 Kumarapalayam Cauvery Mohanur 26.11.2015 2468.18 20.73 31 3022.50 25.39 29 3103.05 26.07 30

3 Manapalli Cauvery Mohanur 27.02.2016 726.00 6.10 31 639.00 5.37 29 648.00 5.44 30

Paramathi 4 Vengarai Cauvery 11.03.2013 velur

Total 3905.18 32.80 93 4303.50 36.15 87 4402.05 36.98 90

39 11. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2016 - 2017

Oct-16 Nov-16 Dec-16

1 Mohanur Cauvery Mohanur 01.09.2014 669.00 5.62 28 1494.00 12.55 30 1164.00 9.78 22

2 Kumarapalayam Cauvery Mohanur 26.11.2015 880.88 7.40 28 695.03 5.84 29.00 799.95 6.72 25

3 Manapalli Cauvery Mohanur 27.02.2016 2334.00 19.61 28 1887.00 15.85 25.00 660.00 5.54 19

Paramathi 4 Vengarai Cauvery 11.03.2013 velur

Total 3883.88 32.62 84 4076.03 34.24 84 2623.95 22.04 66

40 11. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2016 - 2017

Total for the year 2016- Jan-17 Feb-17 Mar-17 2017 Sl Name of Quarry / Date of No. of No. of No. of No. of River Taluk Total Amount Total Amount Total Amount Total Amount No Village Commencement Days Days Days Days Loads (Rs. In Loads (Rs. In Loads (Rs. In Loads (2 (Rs. In function function function functio (2 units) Lakhs) (2 units) Lakhs) (2 units) Lakhs) units) Lakhs) ing ing ing ning

1 Mohanur Cauvery Mohanur 01.09.2014 7206.00 60.53 250

2 Kumarapalayam Cauvery Mohanur 26.11.2015 13060.58 109.71 251

3 Manapalli Cauvery Mohanur 27.02.2016 9453.00 79.41 241

Paramathi 4 Vengarai Cauvery 11.03.2013 999.00 8.39 42 velur

Total 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 30718.58 258.04 784

41 12. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2015 - 2016

Apr-15 May-15 Jun-15 Sl Name of Quarry / Date of River Taluk No Village Commencement Total Amount No. of Total Amount No. of Total Amount No. of Loads (2 (Rs. In Days Loads (2 (Rs. In Days Loads (2 (Rs. In Days units) Lakhs) functioning units) Lakhs) functioning units) Lakhs) functioning

1 Mohanur Cauvery Mohanur 01.09.2014 3267.00 27.44 30 4995.00 41.96 30 7500.00 63.00 30

42 12. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2015 - 2016

Jul-15 Aug-15 Sep-15 Sl Name of Quarry / Date of River Taluk No Village Commencement Total Amount No. of Total Amount No. of Total Amount No. of Loads (2 (Rs. In Days Loads (2 (Rs. In Days Loads (2 (Rs. In Days units) Lakhs) functioning units) Lakhs) functioning units) Lakhs) functioning

1 Mohanur Cauvery Mohanur 01.09.2014 6507.00 54.66 30 3159.00 26.54 29 2742.00 23.03 30

43 12. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2015 - 2016

Oct-15 Nov-15 Dec-15 Sl Name of Quarry / Date of River Taluk No Village Commencement Total Amount No. of Total Amount No. of Total Amount No. of Loads (2 (Rs. In Days Loads (2 (Rs. In Days Loads (2 (Rs. In Days units) Lakhs) functioning units) Lakhs) functioning units) Lakhs) functioning

1 Mohanur Cauvery Mohanur 01.09.2014 1686.00 14.16 30 1455.00 12.22 28 1440.00 12.10 31

44 12. Quarry Wise Sand Sale and Revenue Details of Namakkal District for the year 2015 - 2016

Total for the year 2015- Jan-16 Feb-16 Mar-16 2016 Sl Name of Quarry / Date of No. of No. of No. of No. of River Taluk Total Amount Total Amount Total Amount Total Amount No Village Commencement Days Days Days Days Loads (Rs. In Loads (Rs. In Loads (Rs. In Loads (2 (Rs. In function function function functio (2 units) Lakhs) (2 units) Lakhs) (2 units) Lakhs) units) Lakhs) ing ing ing ning

1 Mohanur Cauvery Mohanur 01.09.2014 1257.00 10.56 27 1278.00 10.74 29 696.00 5.85 31 35982.00 302.25 355

13. PROCESS OF AGGRADATION OR DEPOSITION OF SEDIMENTS IN THE RIVER CAUVERY AND COLEROON OF TRICHY DISTRICT

ASSESSMENT OF THE SEDIMENT FLOW IN CAUVERY AND COLEROON RIVER IN TRICHY DISTRICT

Introducfion

Kaveri river flows in South Kaniataka and flier, to Tamil Nsdu. The Kaveri is one of the major rivers of India, which is considered sacred by Hindus. The Kaveri River basin is estimated to be 27.70D square miles {72,000 km2) with many tributaries including the Shimsha, the Hcraavati River, the Arkavathy River, Honnuhole River, Lakshmana Tirtha River, Kabint River, Bhavani River, the Lokapavani River, the Noyyal Paver and the Amaravati River. Rising in southwestern Kamataka state, it flows southeast some 475 mi (765 km) covering states ofKarrata, Kerala, Tamilnadu and Pondycherry and enters the Bay of Bengal. The river system is u source for agriculture and hydro power. The river enters Tamii Nadu through Dharmapuri district leading to the flat plains where it meanders. It drops into the Hogenakkal Falls just before it arrives in the town of Hogenakkal in Tamil Nadu, The three minor tributaries , Palar, Chennar and Thoppar enter into the Kaveri on her course, above Stanley Reservoir in Mettur. where, the dam has been constructed. Then lite river is joined by tributaries viz Bhavani, Noyyal and Amaravathy and flows up to upper anicut.

The river pass through Dharmapuri. Salem.Namakkal. Karur, Trichy.Thanjavur.Thiruvarur and Nagapatlinm districts in Tamilnadu. At Karur onwards the river becomes wide, with a sandy bed, and flows in an easterly direction until it splits into two at upper Anicut about 14 kilometres west of Thiruchirappalli City. The northern branch of the river is called the. Coleroon or Koilidam while the southern branch retains the name Kaveri and then goes directly eastwards into Thanjavur District. These two rivers join again and form the Srirangair island which is apart of city of Tiruchirapalii. The Choi a king Karikalan has been imniorlalised as he constructed the bank for the Kaveri all the way from Puhar (Kaveripoompattinam) to Srirangam. It was built as far back as 1.600 years ago or even more. On both sides of the river arc found walls spreading to a distance of 1,080 feet (330 »■}. The Kallanai dam constructed by him on the border between Tiruchirappalli and Thanjavur is a superb work of engineering, which was made with earth and stone and has stood the vagaries of nature for hundreds of years. In 19th century, it was renovated on a bigger scale. The name of the historical dam has since been changed to —Grand .Anicut and stands as the head of a great irrigation system in I the Thanjavur district. From this point, the Coleroon or Koilidam River runs north-east and discharges itself into the sea at Devakottai, a little south of Parangipettai.

The Grand Anicut (Barrage) is constructed on the main Cauvery river. At Grand Anicut complex, the river Cauvery splits into two branches Cauvery and Vennar . These two rivers act as die main irrigation canals with the help ef head regulators provided on the both the rivers

separaieiy. These rivers in (uni. divide and sub divide into number of branches which form nemqik al! over dclla and distributes the Cauvcry water in the vast irrigation system. These channels also cany die drainage water and act as irrigation cum drainage channels in the lovvcr dclta.

Alter Grand Anicul, the Kaveri divides into numerous branches and covers the whole ol the delta with a vast network ofimgalion channels in Magapatnam and Tii-uvaur districts and gets lost in the wide expanse ol paddy fields. The mighty Kaveri River here is reduced to tut insignificant channel and enters the Bay of Bengal at the histarica! place of Poompuhar aboul 13 km north of Jharangampadi. (Fig 1 & 2). A. Mohanakrishnan (2011) estimates the irrigation in the beginning of )9lh century as 600000 acres. The first improvements were done by British engineers in 1809 and subsequently by successive governments; the total irrigation was increased to nearly 1000000 acres.

In the absence of water flow the river bed from Karur to Kollidam is always filled with sand and hence inordcr to assess the sediment deposition, this study was taken up as requested by Water Resources Department. PWD,Tiruchy Region

Ca v B a Fradosti / V *rjr «ln; K.^rn^tiika cCtf > - r T ~

r* ■A Etewlion (iHp i / KonciietiBrrv 33V>U;0 1 I 33■ " SKIV. I 135345 Y V 1 'L~l« "-"O Ay I 1 Til ■ SOO m an -sso ) » • jCo QH sc: . «so Ba» - m i Tom Csuvwy RvBr aiitn Sc4iro«r, Kerala CD Slev* Poimdafy Tamil yv com AVa'or 5 fW»/ST CMC. fSPO . .- r " .

13.a. Cauvery River Line diagram

OlMiU: ttaiksy, Harar^ IW btw^l uevtRm (KwaVgt Kn^wi] tvi* f^i j«i>,.N;c.w £V 0- (>». <9*911*. Ptiml iVC- JJK i. ncm "• y^" ' ^»r.< rC'r. j VW

Hcmf^NDaw LklW Cc#ft G'w T.OIftfrVdM aeiW»i&i? w Kr >*xiw Sv

K«11>g Dv. (FyUisHCr«Hr<«] C*W Jrltyii: cyl-7* WCM t ^C^W'Mrnvf'iir Vrvî} CCJKtV.iM s (RrtlljfW. f reJr^J hwriri .'AS JN'W ow.'/vcnva ,i' f,{ j'J^'.'.y; ^v- Ui«MrehMM Om* .HaMMHtfTvimiOv* r.vc-?r;Vcy AAJOX >r»w^l iSCtM.MO^ ' m% •0*rîî"V"V.VW tW;?i7Ciyc»r Kmiv^V 1 ' '• *r.* *25'»} I m 1-

'yl Ufl »■ 0 (1 £ I Ctaareyt OiWai 0V. - C'jit ikOi'.itl- C.s ■ .-liVr C0iie:i;ial) A\ ' i tf. i rnsi^di'^.'^ciii' r5$» >«;'.»«<»»«'• tisfTf 171 O!

Dbjccrivc

C-auvciy receives Eow Irom Metturdam. The read* Jroip Kaun lo Kollidam is veiy wide (Fig 3) .'csulting low flow velocity. This, results in scciimeiualiou process and it was necessary to assess die sedimematkm. Mence the;.study was taken up.

13.b. Cauvery in Tamilnadu

~ f.i Puoucroffy / C ' * ■ MeUur 7tfiTnlNaou II vX^i 1

: .J

v thida'mbaram !W>- , * v-Uroile Wmm %5SSj W ■ ^ v. ^3, ' i 'ir-.w, f t •H ' > 'ijfa . " <•■ JZ*" '* cKu,mB«kon«rn

J;- ... ^i/ucmtaepjiii tri'»nj«wr Nagapaitiisir

Location of irrigation structures

T!ip imporlanl irrigation structures located along the study which arc used for the regulation of water along the reach are detailed below (Fig 4 & 5)

Jeeddarpalayam barrage

Mayanur barrage

Upper anicut

Grand anicut

Lower anicut

13.c. Location Map of Important Anicuts

• ..owefanrc,

% 4-4>> fas ^ ^ppefjpicut^: .' ^ V X

' -i- 2 - ■ - ' jf3rar>d-anicut 3 -•- ;'vw «!- i , i (■ . AS-

13.d. Delta map of Cauvery

.A". '■A m a-

wm.v<%

ie®?!

Climate details

The western side of the catchment mainly experiences the south-west monsoon from June to September and the eastern side experiences noith-east monsoon fioni October to December. The rainfall during the rest of the year is insignificam. The total rainfai! in (he basin across the year can separated into parts. About 50% is received during the south-west monsoon, about 33% in

she nonheasi monsoon, roughly 10% in the pre monsoons and the rest in the winter months. Annual precipitation varies frnm about 700-900 mm in the interior to 1200 and above in the eastern and vvtSslern edges of the basiin

Geology and meteorology of the reach

The region falls mainly- under cretaceous rock tonnalioris. The regional rock Ibrmalion is the. iargcat gmnujiic block of southern granulite teirain of India. It is bounded by Palghar Cauvei y slteai zone in the north and Achankoi! shear zone in die south. It-is dominautly composed of high grade meutsedimcntary rocks, mafic granulites, highland chamockites. Massif Anorthosites and related rocks. The liver Cauveiy is flowing .on. the nonhem and castcni boundaries. The area falls under mcciu alluvial fbrmaiion. The. sand produced by the tide and How of river Cativcry. The sediments of the river Cauveiy are derived from Archean gneissic and charnockitie source regions. The Fdrination of sandy bed in U/S aivl D/S of Barrage based on bore log details reveals that 14m and 9.5m respectively. The chemical analysis reveals that the presence of Mica, estimation ol oxides oi other elements Al,, etc. is found to be small enough to ignore. This pail ol South India experiences semi-arid climatic conditions with moderate rainfall averaging about 63,0mm per year (Fig 6 & 7). The river Can very is perennial river in this region. The seasona! streams and river inlets which get activated during monsoon, often coiilluenee in lo river Cauveiy which ultimately debauches in the Bay of Bengal which is 20DKiVI away frqm the project site.

Topographic elevation varies from lOl.OGm to 95.70in above MSL. The area applied Ibr is river bed in which sand shoals are formed above the sill of the barrage. The shoal ibrmaiions above the barrage ailect the proposed storage capacity of lite barrage and decrease the efilciencv of discharge in downstream side during niaximum Hood.

13.e. Rainfall Pattern along Cauvcry basin

Geology along Cauvery basin Map

CAUVE«Y BASIN 1

M rtOVPWKWEMT QE INDIA . j x' | i ^ \ GliOLOl^V , klCt'/D

* i'7.

Need for the study

Mosi of (lie ume in a year the river in the study reach will have water flow (or irrigation. Alcng Cauvery. Incase of heavy raia in the upper cacchment of Moitar dam. the (low can be excessive and ithe surplus water is diverted through Kollidaih, HcneeKollidam vvi.il be mostly diy ami Can very will have flows. Due to flat slope and wide river nature, the flow velocity will be mostly low (< I'm/s) rest) i ting in sediment formations along the bed of the rivers Cau very and Kollidsin. The seclimcnlalion has resulted Ln decreasing the efficiency of regulators in diverting the flow o f water to the side channels (Plc.l3gtol3j). Hence sand mining was permitted in the river. The sand raining activity is limited to middle reach of the river. The sand mining activity is carried as follows

" Im below theoretical bed unit removal of sliimfs above the bad".

13.(g). Shoaling in River bed

, RMnRRH • ?5lftw^^?'-Tf?5CTi

13.(h). Reduction of River carrying capacity by shoal formation

" 4i

13.(i}. Siltation problems U/S of anicut

i.1 a

I - >, r $S9liS 13.(j).Deita of Cauveiy picture

J9* i#-«-* -VA-A-*-- S^tS-JPP^ * 1 - nf S - n>> I sjesaai asfeji- ^

BSimiJuiMW

Metliodologv adopted

The following are the details of (he procedure adopted for the-estimation of sediment

• Collection of available field details on discharge and sediment

• Calibration of numci ical model using the field data

• Adoption Of suitable empirical relationships for estimating sediment transport

• Evolution of suitable discharge vs sediment transport charts for various slopes of river

In order to carry die studies the river is divided as suggested by PWD in to slopes as detailed (Table 1)

Table! Detaiis of river reach Slope SI no River 1/1800 1 Nerur to Mucombu (Upper anicut)

14.Details of Field Data

(i). Waler level observation at Musiri

The Central water commission How observations were for Musiri site indicate that for a discharge of 575 cumccs the water level at Musiri is S3.480in on 7.2-9-2012 . Initially this cross section was used for the numciica! model studies using numerical model HECK AS , For the present study the U.S. Army Corps of Engineers (2008)' River Analysis System (HEC-RAS) software is used. This software is developed by the Mydroiogic Engineering Center (HEC). which is a division of the Institute for Waler Resources (IWR). U.S. Army Corps n ! Engineers. The details of lite mode! are as bslow

14.(a). Location of CWC gauging site map

(»i)- HLC-RASt One dimensional modoi)

HEC-RAS is designed to perform one-dimensional hydraulic calculations for a full network of natural and constructed channels. The basic coinpuiauoiiui ptoceilure is based on solving the onc-dimensional energy equation using the Mannings' equation in conjunction with the contraciinn and expansion cocfTicients using a procedure similar to the standard step melhod. Thc steady flow water surface profiles computation can handle the subcriticai. supercritical and mixed flow regimes. The in pput to the model are Geoinelnc data, flow data and boundary condition. The output consists of water surface level, velocity and Froude no. in die present con sex t rhe HEC-RAS model mns were perfonued for the observed discharge of 575 cumscs and calibrated to result the water profile as {+) 83.489m, (Pic. 14(a) & i4(b))

I Water levtl by CWC for 5I3Ciiiii/s DO

S:'-

£ 34 txratki't tt.'M • Bod level O) 32 • Model Witter level •h:: - Observed Wotcr Level

/,s

n, "oocooSoooSSSSSS

Alonfg C S (m)

14.(b). Caiibralion slutly result using I1ECRAS diagram

(iii). Field Measu rein en I byWRO, PWD

The Water Resources Dcpl (WRO) ufPWD underTiruchy region is engaged in sand quarry, activities at various sites along Cauvery. One of such site is MPiuliur(10

Mayanm barrage

I4.(c). Location of Mayanur site map

\ - ~ - - cr ncK ••" r> •- i 'i H \\ 5 rv«{: ■ 1 _ _ ... - ■r- — — V - , ritv- V ■ "1 -v, — WK! a =1 v- /r " T 1

i c« •i:z' •iM CO 1XK TYZZiar.'^ :: j»:3 ^3K 1^:: Vi •51! CO 1 -.l: icctr; J.* j! rr« Ji >X y. !?.* >11« 5i;jp rtic: Hfr. W.-flhlfW ««4 S.ICii >r?!i fi h ".p.r 1^:0 atr.-: ««: •i j •« >ei:oH:w TwT r.'.zcc

14.(tl).Ficld obsen ntions at Mputhur diagram

Annual Flow 16000 14000 f 12000 l 1 I 10000 I s:co . ft n GOOD m&z Amuioin 0 w ( MCM ) ! 4000 in ■Avorogc flov; (mcum) 1 S I I ? . ■' { 1 ii 1 ;■ UHli i! Hit r-- 0 r»"> O r* •y^ CO * CO 00 CO 0 O vT» a O C' c*. 0 c. 0 0 0 c\ 0 O0 0 r-i rH T—i r*' r.| rd (N Yenr

14.(e). Flow details 173-2013 diagram

M Fulhur Discharge)

— —• m m m m m *T ^r ^r in tn in un m T-1 •-i < X~i *-4 r-t c-H «-i r-i rH TH «H ▼H w—11 TH -D w —1 >• - D. > o -O >■ c ¥ & t; s a eni Z> Q. "0 3 3 01 o o Q> em n Q. 3 < o Z Q Lfc. S < 5 < *SI o z Q u. 2 < 2 ii

14.(1). Flow details 2013-2014 diagarm

The luial sediiueiit iCcuiiiuialion for the penod from August 2013 to June 2015 alonga width of 500iii works out to 106516m3. This data was adopted to calibrate the approach adopted to estimate the scdinicm calculations based on the discharges.

Estimation nf Sediments

Depending on the size , shape and composition of sediment particles . the sediments arc trail sported as follow

Sliding or rolling

Round and cubical particle will take sliding and rolling modes.

Saltation or Skipping

Partclc movement along small jumps

Suspension

Free movement without contact with bed.

Types ofset/iitient load

The sediment transport cd by stream consists of bed load, suspended load and wash load, In the present study bed load estimations are made.

Bed deforwations

The bed of stream transporting sedimsnl under usual conditions of How develops undulation. The various undulations arc ripples, dunes, and plane bed, standing wave and anti dunes.' (Fig 19 & Table 2).

TyocSl rippie pJueirs

Piene beo

tXKie? wits ppples superposei

Anti June vanijng wave

Dunes

ArsMurie- treoiftog'Wavs

WtesheJ cut curses

15.(a). Flow regimes pictures Sam! size and density

1 The effective sizeofsandparticle D?,, is 0.4min, Mass Density is (()s) 1 SSOKg/ur

The flow regfmcs are identified as follows based on bed Shear stress r0 and critical shcai stiess "c.

T„=rwrisfl

Tc.-7c/(g(ps-pw) fl)

Bed load estimation

The transport rate of sediments in the bed load qi, is usually referred in units of weight per second per unit width (N/a'm). A very Ikrge number of empirical relations are available. Two main parameters used are bed Shear stress To and critical shear stress tc. In alluvial channel the particles will start moving when bed shear stress exceeds critical shear stress. The most widely used expression is (hat od Meyer-Peter-and Muller (1948). This relates a parameter called shear stress parameter •f with bed load .function

T*. (YwR So / (Yi-Tw) d) (N/N)

d)b-8(T. -0.047)2a = (qh/ (gdV") (l/( (VV Yw)-1),/J) where

Qb = Bed load in Pf/s/m

d = mean sediment size (m)

Y% = Unit weight of sediment particle

Tw = Unit weight of water

N, = Mannings Coeff for particle roughness = (d"6/21.1)

N = Mannings coeff for channel

R = Hydraulic mean radius

So = T.ongitudinal slope of channel

Table 2 Garde & Rengaraju method for analysis of bed form

' SI no (To / Tc) ratio Flow regime i[ [ ! Less Than 1 | No motion 1 2 Between 1 and 0.28(R/d)a M Ripples & Dunes

Between 0.28(R/d)CJ4 and i 3 Transition. !.I8(R/'d)0^

4 Greater than Antidunes

Bed had estimation

Hie transport rale of sediments in the bed load qi, is' usually f^ferreci in units of weight per Second per unit width (N/s/nv). A very large number of cnipirjea! relations arc-available: Two inaih parameters used are bed. Shear stress To and critical shear stress tc, Ic alluvial chahnel the particles: will start moving when bed shear stress exceeds critical shear stress. The most widely used expression is that od Meyer-Peter-and Muller. this relates, a parameter called shear stress parameter '%.• with bed ioad .function ^fa. The approach lakes in to account bed slope, particle size ahc discharge ■Which arc die main parameters. t.- (R So / (YrYw) d) (Ns^J)

<{)b.= 8 (T. -0.047) •VJ = (qt/ (gd3)"2) (I/( (T^T^-l)"2) Where.

Cfij — Bed load in N/s/m

d = mean sediment size (m)

Ts= Unit Weight of sediment particle

Unit weight of water

Ns = Mannings Coeff for particle roughness - (d1/6/2LI)

N = Mannings coeff for channel

R= Hydraulic mean radius

So = Longitudinai slope of channel

HEG-RAS model run

The input

Four cross sections along M Puthur

Longitudinal slope

Discharge values from August2013 to June 2015

The output

Velocity (Mean)

Flow across cross section for various discharges

Froude no

The above values of the model run for various discharges arc extracted from the output of HECRAS. From the output the average flow depth forvorious discharges are evaluated and furnished below.. A typical output for discharges of 604 cumecs (PF1) and 53 cumccs (PF2) arc given below (Fig 20, & 21)

KayetyMpulliurHEC Plan; Plan 05 12/6/2015

legend

EGPf \ EG PF19 Ground Bsnt Sta

S30 1000 ISM Slafcti tm) I'tr

15.(b).Ty]>ical HECRAS results with cross section diagarni

Jiedi ; fell m QJ'ia. mm W.S Elev crfts; E,G;5tee MM Fioi^iel Io?Wi# i^iSS ijil [nil : N 1 ;i ti [n# m 1 ' 1.. i PF l, , B04I 94,25 35.90' 85.99 am 0.46 1304.31 181521 tt17 jl 4 Ff2. 410.81 94,25 35,81: 95.821010343 0,41 '39230 1805211} 0,18 1 w m 39531 94.25 35.79 £80} O.OOQ348i 0.41 965,07 1804,08 0,18 ,1. , m i 180.,95 34,25 9554: 95.54' mm 0.33 540.53' 1397,18 0.1? 3'' 4;. PFS ; 22.64 9425 95.0) -95# oceosi oil ml t^TS] ftii "4. 4... :• Wk,,' 148.891 94.25 95.49 95.49i 0,000338 6,32' 471.80 1277.73: 0.17 V 4 "i ft; 20.53 94,25 94.90! 94.3110.000544^ 0:30: 68.14 28245 0.20 : 1 m i 18,13 94,25 94871 94.8?i 0.060553; 0.31 j 58.90 24131 020 4 : PF5 y 83.01; 94,25 £■331 95.33} maS\ 0.28 231,59 9691: 0.17 4 . 17.86 94,251 94.87! | 34.87. (lffl05S; 831 57.90 236.421 0,20 1 t' :• 4 "1 mi 26.711 94,251 85.(161 95.06i 0.0®21S; 0.22 121.04 404,301 113 } 4 fits 48.571 94.25 85.191 9620 0.000272 0,26: 186.13 569,33; 0.15 -f \ 4: :m 30245 94,25 SfitOi 95.71 0.000364 0.38, 795.31 1721.321 0.18 I 4 : mm 541:78 9425 85:93: 3594 attKBII 0.45 1207:72 181360 018 1' : i Ffis: 333.671 9425 95.73! 35.74| 0.KI036C 039! 354.39 1758,63 ais : 3- - 4 FIG 140.30 94.25 95,47 95.481 0.000336 0.31 45234 1249.31 aie •i 4 Fl? 238.12 9425 35.62; 95# 0.000386 3.36' 563.341 1633,13 0.18 h 4 F'e 21498 94.25 .159! 95,59! 010386 0:351 313,79| 1589# 0.18 r 53.03 94.251 95.211 9622 9.030301 9.2? 1982? 630.34 ,0.15 i i m 37.74 94.25r 35.14! 951410.0X238 0,24 ). 156:99 430i£ 0.14 i i m' 67.31 94.25: 9527] 9528' 0.0X063 028 [ 241,96 634,99 0,16 r i 4 -m 5292 94,25 95.21 i 9522 O.OMfi 0,2? 19796 628146 0.15 i 4,. m 40,33 94,25 95,15: 35,16 0.0X12471 025 : 164,24 '51136 0,14 1 PF:24 l?5fl0,00 84.25 100.37 100,45 0.(00183' 131 9545,53 19241 0,19 r-s I

Typical HECRAS results in tables for different flow data

Flow data analyses

The sand mining actiyities were regularized through P WD in the year 20U3 Hence the flow data in-Cauvery froth the year 2004 to 2015 was collected and .analysed. The monthly values for lite periods are presented . The high yalues were observed during the period 2005^06 and 2007-08. Apart froth these the flows during other years were nominal, in m inigation year commencing

fiom June and endind in May. the flows were mainly observed during July to January. During the other months minimum flow was seen. (Fig 22)

Flow 2004-2015

1200.00 20CW-05 1000.00 2005-06 2006-0? soo.oo 2D07-0S 600.00 2003-00 I —-2000-10 400.CO i .- £ N->: St 2010-11 2CO.OO A 2011-12 o.co 2012-11 ^ O Z O 2 > S — s ^ ti Q 2 2013-14 Mon:h — 2014-15

I5.(c). Monthly flow over a decade diagarm

The analyses of the flow data indicates that river cauvcry flows diraughout die year with values varying from a minimum lo maximum value. Because of the flows there will be some depositions along the bed. The low flow velocity will result in deposition of the materials carried. Based on the discharge values the bed form will take place.

Table 3 Hydraulic calculations j SI no Discharge (Cumcc) Velocity (itl's) Flow Regime

. ... — i l 604.35 •0.46 • 2 410.85 0.41:

3 395.31 0.43 1

4 180.95 -Ripples and Dunes i 0.33; j for all the flow 5 222.64 0.35 values under serial 6 14B.89 • 0.32 no 1 to 23

7 20.53 0.3 1

8 18.13 0.31,

9 83.01 0:28

10 17.86 0:31

n 26.71 0.22 • 12 48.57 0.26 . 13- 302.45 0.38

14 541.79 0,45 l 333.67 . 0.39 16 140.38 0.31

17 238.12 0.36

I 18 214.98 0.35

19., 53.03 0.27

20 37.74 0:24

21. 67.31 0,28

22 52.92 0.27 1 i 23 40.39 0.25

Table 4 Hydraulic number

SI ho Discharge (Cumec) Velocity (th/s) Ff number Depth (m)

... s 604.35 - 0.46 0.17 . 0.75 ? 410.85 0:44 0.18 0:53 3 395.31 0.41 0.,i8 0.53 4 180.95 0.33 0,17 038 5. 222.64 035 0.18 0.39 6 148.89 032 047 0.36 •7 20.53 " 03 0.20 0.23: 8 ! 8.1:3 0.34 0,20 0.24 9 83.01 0.28 047 0.28, 10 1786 03! 0.20 0.24 n 26.71 0.22 04:3 0.29 12 48,57 026 045 0.31 13 302.45 038 0.18 • 0.45 1,4 541.79 0.45 048 0.64 !5 333:67 0.39 0.18 0.48 16, 140,38 031 0.16 038 ,17 238.12 0,36 048 0.44 18 214.98 035 0,18 0.39 19 53.03 0.27 0.15 ,0,33 ■20 37.74 .0.24 0.14 0.30 21 67,31 0.28 0.17 0,28 22 52.92 0,27 045 0.33 23 40,39 0.25 0.44 0.33

The maximum velocity was 0.46m/s and the corresponding flow depth was 0,75m., In all the flows,the Proudc number was less than ;i indicating sub critical fiyw.

Table 5 Bed load parameters

SI no Discharge T* (Shear Parameter) tf'hbed t)b (Be

1. 50435. 0.359186, 1.3954 0,55 2 410.85 0.254521 0,7563 0,30 3 395.31 0.254521 0.7563 4 180.95 0.184855 0.4095 0,30 5 222.64 0,135478 0.4123 0,16 6 148.89 0.173822 0.3613 0.16 7 20.53 0.110378 0.1276 0.14 8 18.13 0.11786 0.1509 0 05 9 83.01 0.133082 0.2021 0.06 10 17.86 0.11786 0.1509 11 26.71 0.140495 0.2287 0.08 12 48.57 0.147389 0.2545 0.06 13 302.45' 0.218637 0,5689 0.09 14 541,-79 ' 0.306607 1.0582 0.10 15 333.57 0.230296 0.6278 0.22 16 140.38 0.134156 0.4064 17 238.12 0.196228 0.4612 0.42 18 214,98 0.185478 0.4123 0,25 19 53.03 0.158945 0,2996 0.16 20 37,74 0.144158 0.2423 0.18 21 67,31 0.133082 0.2021 0.16 22 52.92 0.158945 0.2996 23 40.39 0.156432 0,2896 0,12 0.10 U.Uon aq 0.12 0.11

Total (N/s/m) in two years = 3.96597465

Table 6 Bed load estimations

SI no Discharge Bed load (Kg/m/rrtonth Bed load (Cumec) (Kg/m/month)

1 604,35 142400.551 142401 2 410.85 77176.63677 77177 .3 395.31 77176.6367? 77177 4 • 180.95 41785.55725 41786 5 222.64 42069.10414 42069 6 148.89 36870.69526 36871 7 20.53 13025.77551 13026 8 18.0 15398.90122 15399 9 83.01 20618.69933 20619 IQ 17.86 15398.90122 11 26.71 23338.49101 23338 12 48.57 25967.03188 25967 13 302.45 58050.78997 58051 14 541.79 107985.4669 107985 15 333.67 64064.86126 64065 16 140.38 41467.89999 4:1468 17 238.12 47061.76628 47062 18 214.98 42069.10414 42069 19 53.03 30577.22378 30577 20 37.74 24727.17751 24727 21 67.31 20618.69933 20619 22 52.92 30577.22378 •30577 23 40.39 29553143396 295S3

Tola! (Kg/ni/23months) 1027980

Total (Mt/ni/23months) 1028

Total (Tons/in/Year) 53,6

TotalCTon/Year) for ave 588528 flow width of 1098m

Calculations fnr 5flfini width mpfls»reinent

Total quantity measured in 11 months = 106516 m3

Quantity (MT/year/500m width) = 191729 MT

Quantity (MT/m/year/) = 383 MT/m/yr

Quantity assessed as above = 536 MT/m/Vr

Quantity assessed (m3) per annum = 148888 m3

The above quantity indicates a formation of 76cm of sand height in the quarried area of 380i length by 500m width against observed average of. 5,6cm The approach adopted for bed loa transport reasonably agreeing with the approach.Based on the above discharge vs Sediment be load is given for Reaches below. The sediment transport.is given in terms weight units per men width per month. It can be converted in to volumetric units; Based on regression analyse equations are also derived for the assessment.

Rqach from Nerur to Mqcombu aloqg Cauvery

Sedimentation -Cauvery 25 y.*: 2M5*H 0XU7* 0.247 Rz ' O.P60

£ iO

100 2C0 300 4,00 500 000 700 FloWtcumeCs)

15.(d). Sediment depth formation in Cauvery diagram

Table 7 Monthly Sediment formation with Monthly flow for different reaches

Flow (Cumec) Cauvery Sediment Depth (cm)

100 5.147

200 7.447

300 10.147

400 13.247

500 16.747

600 20.647

700 24.947

800 29.647

900 34.747

1000 40.247

16. DRAINAGE SYSTEM WITH DESCRIPTION OF MAIN RIVERS

S.No. Name of the River Area Drained % Area drained in the (Sq.Km) District

1 Cauvery 3295 98%

2 Tirumanimuthar 1183 36%

3 Sweta Nadhi 673 2%

4 Karaipottanar 1547 46%

17. SALIENT FEATURES OF IMPORTANT RIVERS AND STREAMS:

S. No. Name of the River or Total Length in Place of Origin Altitude at Stream the District (in Origin (m) km)

1 Cauvery 85.80 Talakaveri, 1341 Karnataka

2 Thirumanimuthar 56 Arunuthimalai 1033 Hills and Shevroy’s hills

3 Karaipottanar 52 Kolli hills -

4 Sweta Nadhi 50 Kalrayan hills 1266

18. MINERAL POTENTIAL OF THE DISTRICT

Mineable mineral Average width of Area Portion of the Length of area potential (in area recommended recommended for River/Stream recommended for metric Total for the S.No. River / Stream for mineral mineral recommended for mineral concession Tonne)(60% of District concession (in concession (in mineral concession (in Kilometer) total mineral meter) Square meter) potential

1 Cauvery Full stretch 85.80 600 51.48 x 106 101.93 x 106 101.93 x 106

19. ECONOMIC IMPACT OF MINING

The mining will generate direct and indirect employment during mining operations. In general there will be no adverse effect on human health as no blasting or handling of toxic material involved in sand mining. All the safety measures will be strictly followed to prevent occupational risk during excavation, loading and transportation.

The State is highly urbanised State after Maharashtra, the sand mining operation in the District will be the backbone for infrastructural development besides generate the revenue to the Government. Since the operation is carrying out by the Public Works Department they properly identify the aggradation area over the river bed in the district. This may be useful to maintain the hydrogeological cross section of the river to carry the maximum flood discharge.

20. CONCLUSION/RECOMMENDATION:

The Namakkal District is one of the largest urban agglomerations in the state. The detailed scientific study reveals that the Cauvery River carrying sand sediments whenever there is sufficient flows along its entire length in the District. This cumulative sediments have resulted in shoal formation and reduce the carrying capacity of flood nearly 4,80,000 cusecs. The properly managed sand mining activities are recommended in Cauvery. Hence, it is concluded that, the permission of sand quarries in the potential areas of river in the District will be beneficial for infrastructural development of the state of Tamil Nadu.