The Somasila Project was constructed across river Pennar near Somasila Village of Anantha Sagaram Mandal in S.P.S.R. Nellore District with a Gross storage capacity of 78.00 TMC at FRL +100.58 Mts (+330 Ft). River Pennar originates on the slope of Nandi hills in Karnataka State, and the basin of Pennar River is fed by a number of tributaries viz Cheyyeru, Papagni, Chitravathy, Kundu and Sagileru.
The foundation stone for this project was laid on 04.06.1975 by the then Hon’ble Chief Minister of Andhra Pradesh Sri Jalagam Vengalrao garu.

b) Objectives of the Project:

  1.  To stabilize 4, 05,500 Acres of wet ayacut besides creating an irrigation potential of 1, 79,000 Acres new ID to a total of 5, 84,500 Acres.
  2. To Transmit 15 TMC of Krishna water received from Pothireddypadu Head Regulator to Kandaleru Reservoir for Chennai Drinking water supply.
  3. To transmit Pennar flood waters 30 TMC to Kandaleru reservoir for irrigation of 3,00,000 acres under Telugu Ganga Project in Nellore and Chittoor districts.
  4. To divert 5.00 TMC of Pennar flood waters through High level Canal (Lift Irrigation Scheme) to provide Irrigation and Drinking water facilities to the upland drought prone areas in Udayagiri and Atmakur constituencies.
  5. Industrial water supply 0.8 TMC (IFFCO from Kanigiri Reservoir is: 0.8TMC) in Nellore district.
  6. To supply 1.7 TMC of drinking water (Nellore Municipal Corporation: 1.30 TMC + Kavali Town: 0.3 TMC + Atmakur Municipality: 0.1 TMC) to Nellore Municipal Corporation, Kavali & Atmakur Towns.
  7. Power Generation to a capacity of 12 MW is in operation (approval accorded for additional capacity of 11 MW which is under construction).


c) Clearances:

The Planning Commission, Government of India have accepted Somasila Project Stage.1 for inclusion in Vth five year plan vide letter No.II/15(1)/21/72 I&CAD, Dt.21.09.1973 and the original estimate of Rs.17.20 Crores was accorded administrative sanction by Government of Andhra Pradesh vide G.O.Ms No.1214 PWD, Dt.27.11.1973 and Technical Sanction was accorded by the Chief Engineer, Major in No.74/1975-1976.

Revised Administrative Approvals:

1st Revised Estimate i.e. 02/1984 : Rs.147 Crores
2nd Revised Estimate i.e. 04/1987 : Rs.199 Crores
3rd Revised Estimate i.e. 06/1992 : Rs.296 Crores
4th Revised Estimate i.e. 06/1996 : Rs.467 Crores
5th Revised Estimate i.e. 08/2006 : Rs.1196 Crores
6th Revised Estimate i.e. 06/2013 : Rs.1548.49 Crores
(The latest Revised Estimate – Administrative approval accorded vide GO Ms.No.91 I&CAD (PW:M&MI- R1) Department Dt.20.09.2013 for Rs.1548.49 Crores)


State : Andhra Pradesh
District : Sri Potti SriRamulu Nellore
Village : Somasila.
Basin : Pennar Basin
Longitude : 79o-18’- 25” E.
Latitude : 14o-29’-15” N.
Total Ayacut : 5, 84, 500 Acres
Stabilization of wet Ayacut : 4, 05, 500 Acres
New Ayacut : 1, 79,000 Acres
Catchment area at Dam Site : 48,645 Sq. KM. (18,790 Sq. Miles)
Free Catchment : 20,900 Sq. KM. (8,073 Sq. Miles)
Intercepted Catchment : 27,745 Sq. KMs. (10,717 Sq. Miles)


Minimum River bed : + 67.07 M (+ 220.00’)
Maximum water level : + 101.80 M (+ 334.00’)
Full Reservoir Level : + 100.58 M (+ 330.00’)
Crest Level : + 86.868 M (+ 285.00’)
Minimum Draw Down Level : + 82.30 M (+ 270.00’)
Dead Storage Level : + 82.30 M (+ 270.00’)
Live storage : + 1.994 TM Cum (70.421TMC)
Water spread area at FRL+ 330.00’ (+100.58 M): 212.285 Sq KMs. (82 Sq. Miles)
Water spread area at MWL+334.00(+101.803 M): 232.14 SqKMs(89.63 Sq Miles)


Maximum Water level : 2.483 TM CUM (87.680 TMC)
Full Reservoir Level : 2.21 TM CUM (77.98 TMC)
Crest level : 0.463 TM CUM (16.36 TMC)
Minimum draw down level : 0.214 TM CUM (7.567 TMC)
Dead Storage level : 0.214 TM CUM (7.567 TMC)


Type of Dam : Zoned Earth Dam
Length of Dam : 352 Mts. (1155 Ft.)
Top width of Dam : 18 Mts. (59.068’)
Maximum height above GL : 38 Meters (347.68’)
Top level : + 105.95 M ( 347.68’)
No. of river sluices : 2 Nos.
Sill level : + 76.20 M ( 250.0’)
Size : 2.40 M x 3.60 M(7.87’ x 11.81’)
Sill level of river sluice in 19th block : + 70.10 M ( 230.00’)


Top level : + 105.15 M(345.00’)
Deepest foundation level : 74.50 M (244.43’)
Length (including 19th Block) : 172.53 M (566.04’)
Excluding 19th block : 157.28 M (516.04’)
Width at top : 6.25 M (20.50’)
Width at deepest foundation level : 25.143 M (82.51’)
Maximum height above deepest foundation level 30.65 M (100.56’)


Type of spill way : OGEE TYPE
Full Reservoir level : 100.68 M (330.00’)
M.F.L. : 101.80 M (334.00’)
Length : 236.21 M (775.00’)
Maximum height above the deepest foundation : 30.45 M (99.91’)
Crest level : + 86.868 M (285.00’)
Number of gates : 12 Nos.
Type of gates : RADIAL GATES
Size of gates : 15.24 M x 14.168 M
Top of Gates : EL + 100.736 M
Maximum discharging Capacity at F.R.L 19,680 Cumecs.(6,95,000C/s)
Maximum discharge capacity at MWL 22,375 Cumecs (7,90,000 C/s)
Tail water level + 76.80 M (251.97’)
Energy dissipating arrangements Solid bucket and stilling basin
with Baffel blocks .

Head regulator Left Right
Total Length 4.00 M ( 13.12’) 9.00 M (29.53’)
Length of Bay 2.00 M (6.56’) 3.00 M (9.48’)
Sill level + 79.25 (260.00’) + 81.38 ( 267.00’)
Number of Gates 2 Nos. 3 Nos.
Size of Gates 2.0 M x 2.0 M – 3.00 M x 7.5 M (6.56’x 6.56’) – ( 9.84’ x 4.61’)

Capacity at sill level of LHR +79.25 M (260.00) 4.14 TMC
Capacity at sill level of RHR + 81.38 M ( 270.00) 6.445 TMC


Non over flow Dam Top level + 105.156 M
Block No. 1: 0 M to 22.86 22.86 M
Block No. 2: 22.86 M to 45.72 M 22.86 M
Block No. 3: 45.72 M to 68.58 M 22.86 M
Block No. 4: 68.58 M to 91.4 M 22.86 M
Block No. 5: 91.44 M to 119.53 M 28.09 M
Block No. 6 : 119.53 to 142.03 M 22.50 M
Block No. 7: 142.203 M to 157.28 M 15.25 M
157.28 M


From 157.28 M to 393.49M 236.21 M
Crest Level + 86.868 M
Top of Crest Gates + 100.736 M
Block No. 19 from 393.49 M to 408.85 M 15.26M
Top level 352.00 M


From 424 M TO 776 M 352.00 M
Top level + 105.15 M (345.00’)
Total length of gravity Dam in block 1 to 7 and
Block No. 19 + 157.28 + 15.26 = 172.00M

e) Components of Works:

A. Dam & Appurtenant Works:

The construction of dam and appurtenant works were commenced in the year 1976 and completed during the year 1989 and the reservoir is impounded to a maximum capacity of 73.017 TMC on 30.11.2010 against its full reservoir capacity of 78.00 TMC. The Project consists of 3 Canals i.e. 1) G.K.N. Canal/North Feeder Channel, 2) South Feeder Channel and 3) Bezawada Papi Reddy Canal/Kavali Canal. The Canal wise details furnished below.

B. CANALS (03 Nos):

(1) GKN CANAL (NORTH FEEDER CHANNEL): The GKN Canal takes off from left side head regulator of Somasila Dam and original length of canal is 73.920 Kms. The excavation and construction of structures is completed except in forest reaches. The ayacut so far developed is 41,400 Acres as against the contemplated ayacut of 43,000 Acres. The GKN Canal Extension (from Km.73.920 to 104.50 up to Rallapadu Reservoir in Prakasam District) was taken up under Package.32. The contemplated ayacut under canal extension is 98,500 Acres (Nellore District: 58,500 Acres & Prakasam District: 40,000 Acres).
(2) SOUTH FEEDRER CHANNEL: The Canal takes off at Km.2.58 of SKFF Canal which starts from right side head regulator of Somasila Dam and length of Canal is 74.725 Km. The excavation and construction of structures is completed except in forest reaches. The ayacut so far developed is 35,500 Acres as against the contemplated ayacut of 41, 000 Acres.
(3) BEZAWADA PAPI REDDY CANAL (KAVALI CANAL): The Canal takes off at Km.1.609 of Kanigiri Reservoir Feeding Channel which starts at Sangamanicutand length of Canal 67.619 Km. The excavation and construction of structures is completed except in forest reaches. The ayacut so far developed is 74,000 Acres as against the contemplated ayacut of 75,000 Acres.



Irrigation Potential Mandals Covered:

The Mandals covered are Ananthasagaram, Atmakur, Marripadu, A.S.Peta, Kaligiri, Kondapuram, Dagadarthi, Jaladanki, Sangam, Kaluvoya, Chejarla, Podalakuru, Nellore Rural, Kodavalur, Bogole, Kaligiri and Kavali.

f) Submersion and Rehabilitation:

Due to construction of Somasila Reservoir 108 villages will be submerged in the foreshore of somasila Reservoir affecting 20,000 families in Kadapa District.
The maximum storage so far made in the reservoir is 73.017 TMC (327.76’) on 30.11.2010 against FRL of 330.00’
The details of acquisition made are indicated below.

S. No Category Proposed Acquisition Acquired             so far Balance to be Acquired
1 No. of Villages 108 108 —-
2 Patta lands (Acs) 21,617 21,617 —-
3 Govt. Lands (Acs) 32,274 32,274 —-
4 Village structures (No) 35908 35,908 —-
5 Lok-adalath cases (No) 1988 1698 290
6 Total Cost ( cores) 420.00 679.07 —-

Payment for the lands and structures are completed except in some pockets which are involved in court cases.
There is no R&R under this project in terms of G.O.Ms.No.58, I&P (Projects) Dept. dated 19.3.1980. The Govt. in the said G.O. have issued orders that no new rehabilitation centers should be set up under any project and it is decided that the displaced families of Somasila Project should be paid ex-gratia cash grant in lieu of rehabilitation facilities at the rates prescribed therein. The evacuees received ex-gratia payment and settled themselves at the places of their choice.

g) Status of Works:

1) Package Works on GKN Canal, SFC & Kavali Canal:

Modernization work on GKN Canal (North Feeder Channel) was taken up on EPC system under Package.11 and Package.96 i.e. from Km.0.00 to Km. 73.92 to increase the carrying capacity of canal from 380 C/s to 772 C/s and Extension of GKN Canal (North Feeder Channel) from Km. 73.920 to Km 104.50 was also taken up under Package.32 to feed Rallapadu Reservoir and to create 98,500 Acres of new ayacut with a total amount of Rs.211.844 Crores. The Progress of all package works and their status is hereunder.

2) Non-Package Works:

The works of Drilling & Grouting of Left side retaining wall of SKFF Canal and Energy dissipation on downstream spill way of Somasila Dam are in progress in respect of SP Division No.1, Somasila.
The works of Construction of Pick up weir across Upputeru river near Chintaladevi village, Kondapuram mandal, SPSER Nellore District and Conducting DGPS Survey & mapping for the forest lands for canals and foreshore submersion and CA lands as desired by the FAC (Forest Advisory Committee) were completed in respect of SP Division No.4, Atmakur.
The works of Restoration and Improvements to DPs under South Feeder Channel are near completion in respect of SP Division No.6, Nellore.

h) Land Acquisition under 3 Canals:

Total land required : 2973 Acres
Total land requisitioned : 2898 Acres
Total land acquired : 1817 Acres
Balance land to be acquired : 1081 Acres


The forest lands required for canals and foreshore submersion is 1014.85 Ha. The details are as follows.
Kavali Canal : 124.07 Ha.
G.K.N.Canal (North Feeder Channel) : 85.47 Ha.
South Feeder Channel : 64.17 Ha. &
Foreshore Submersion : 741.14 Ha.
Total : 1014.85 Ha
The Hon’ble Supreme Court of India has granted permission for 1016 Ha. of forest land required for Somasila Project with the conditions as stipulated by the Central Empowered Committee. In this connection, the DGPS survey work (as desired by 11th Forest Advisory Committee) was completed for 1014.85 Ha of forest land and 1133 Ha of CA land and the entire process in accordance with 11th Forest Advisory Committee was attended and the consolidated report along with DGPS maps were submitted by the State Government to the MoEF, New Delhi on 08.06.2018 for further process. In this regard, the 12th Forest Advisory Committee meeting was held on 19.12.2018 in which the Stage.1/Principle approval was accorded and payment of NPV is awaited from the DFOs concerned which is in process.

j) Annual Budget:

Budget Proposed for the year 2019-20 is : 366.07 Crores