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Ground Water is a Precious National Resource - Preserve it, Protect it and Don't Pollute it.

State Profile 
Ground Water Scenario of Tamil Nadu

Area (


Rainfall (mm)


Total Districts / Blocks

32 Districts


Nearly 73% of the total area of the State is occupied by a variety of hard & fissured crystalline rocks like charnockite, gneisses and granites. The depth of open wells varies from 6 to 30mbgl. While the depth of borewells generally varies from 30-100m. The sedimentary formations consist of sand stones, limestones and shales whereas Quaternary sediments in the State represented by Older alluvium and Recent alluvium and coastal sands. In the Cauvery delta of Thanjavur District, the artesian pressure head ranges between 4.5 m to 17 magl with free flow up to 270 m3/hr. The yield of wells in the alluvium varies form 27 to 212 m3/hr. The yield of wells in the fissured formations varies from 7 to 35 m3/hr.

Dynamic Ground Water Resources (2011)

Annual Replenishable Ground water Resource

21.53 BCM

Net Annual Ground Water Availability

19.38 BCM

Annual Ground Water Draft

14.93 BCM

Stage of Ground Water Development

77 %

Ground Water Development & Management

Over Exploited

374 Blocks


48 Blocks

Semi- critical

235 Blocks

Artificial Recharge to Ground Water (AR)

  • Area identified for AR: 68839 sq km
  • Volume of water to be harnessed:712.30  MCM
  • Feasible AR structures:
  • Percolation tank- 5388
  • Check dam/NB- 16163
  • Recharge Shaft- 154578
  • Recharge tube well- 743
  • RT(KM)- 539
  • Farm pond/Recharge pond-16163

Ground Water Quality Problems


Districts affected (in part)

Salinity  (EC > 3000 µS/cm at 25 ° C)

Arriyalur,Chennai, Coimbatore, Cuddalore, Dharampuri, Dindigul, Kancheepuram, Karur, Nagapattinam, Namakkal, Perambalur, Pudukkottai, Ramnathapuram, Salem, Sivaganga, Thanjavur, Theni,Tiruppur, Thiruvallur, Tirunelveli, Trichchirappalli, Tuticorin, Vellore, Villupuram, Virudhunagar.

Fluoride (>1.5 mg/l)

Coimbatore, Dharmapuri, Krishnagiri, Namakkal, Kancheepuram, Puddukotai, Ramanathanpuram, Salem, Sivagangai,   Thiruvannamalai, Tiruchirapally, Tiruppur, Vellore, Virudhunagar

Iron (>1.0 mg/l)

Namakkal, Salem

Nitrate  (>45 mg/l)

Ariyalur,Chennai, Coimbatore, Cuddalore, Dharmapuri, Dindigul, Erode, Kancheepuram, Kanyakumari, Karur, Madurai, Namakkal, Nilgiris, Perambalor, Puddukotai, Ramanathanpuram, Salem, Sivagangai, Theni, Tiruppur  Thiruvannamalai, Thanjavur,  Tirunelveli, Thiruvallur, Trichy, Tuticorin, Vellore, Villupuram, Virudhunagar

Heavy metals:
   Lead (above 0.01 mg/l)
   Cadmium (above 0.003 mg/l)
   Chromium (above 0.05 mg/l)

Lead : Dindigul, Tiruvallur, Kancheepuram
Cadmium : Tiruvallur
Chromium: Cuddalore, Dindigul, Erode, Kanchipuram, Tiruvallur

Central Ground Water Authority

Areas Notified for Regulation of ground water development
  • Pollachi_S Block of Coimbatore District
  • Morappur Block  of District Dharmapuri
  • Pappireddipatti Block of District Dharmapuri
  • Usilampatti Block of District Madurai
  • Kuttalam Block of District Nagapattinam
  • Rasipuram Block of District Namakkal
  • Attur-S Block of District Salem
  • Gangavalli Block of District Salem
  • Panamaruthupatti Block of District Salem
  • Talaivasal Block of District Salem
  • Veerapandi Block of Salem
  • Chengam Block of District Tiruvannamalai
  • Valangaiman Block of District Tiruvarur
  • Udangudi Block of District Tuticorin
  • Gudiyatham Block of District Vellore
  • Jolarpet Block District of Vellore
  • Pernampet Block of District Vellore
  • Tiruppathur Block of District Vellore