Somasila Reservoir is constructed across River Pennar near Somasila, village of Ananthasagaram Mandal in Nellore District of Andhra Pradesh.

The Project envisages storage of 78.00TMC of water at F.R.L. +100.58M. The contemplated ayacut under the project is 5, 84,500 acres in SPSR Nellore and Prakasam Districts. Out of which stabilization of wet ayacut under Pennar Delta Kanupur canal system and existing tanks in up lands is 4,05,500acres and new I.D.is1, 79,000 acres. Out of the above ayacut an extent of 82,500 acres stabilization and 1,35,000 new I.D is under Somasila Project canals viz., GKNC Canal (North Feeder Channel ), south feeder channel and Kavali canal.The allocation of water for the above ayacut is 60.892 TMC. It also envisages to transmit 30.00 TMCof water to Kandaleru Reservoir under Telugu Ganga Project for irrigating 3, 00,000 Acres of I.D. ayacut in Nellore and Chittoor Districts besides 15.00 TMCof Krishna water to Chennai city for drinking water purposes. In addition to the above 2.40 TMC of water was allocated to Nellore, Kavali, Gudur and Tirupathi towns for drinking water needs.

The Andhra Pradesh State Electricity Board has sanctioned 2 x 5 M.W. Mini HydelScheme for Power Generation at Somasila Dam, Nellore District for captive utilization in G.O. M.S.No.180, dated 29.12.1994 in favour of M/s.Balaji Power Corporation Private Limited. Further the Government in G.O.Ms.No.100 I&CAD. TGP-I(2) Department, dated 9.7.1999 have issued no objection certificate to hand over the scheme to the said firm for implementing the Power Project. Accordingly the firm has executed the Mini Hydel Project including civil, electrical and mechanical works and water is being supplied to power house and project is commissioned in the year during December 2005and it is enhanced to 2 X 6 MW i.e. 12 MW. Approval accorded for an additional capacity of 11 MW and will come into operation in due course.

Salient Feature
Location of Head works :
Village : Somasila
Mandal : Ananthasagaram
District : Nellore (Foreshore area in Kadapa Dist.)
River/Tributary : Pennar River
Nearest City/ Town (including KMs.) : Nellore 90 KMs
Name of the upper stream projects : Mylavaram Dam, Cheyyeru Project and Lower Sagileru.Project (Complete).
Village benefited : 101 Nos
Mandals benefited : 15 Nos
Catchments area : 48,645
Maximum Flood discharge (observed) : 6,26,274 Cusecs, 2001year
Designed Discharge at F.R.L : 6,95,000 Cusecs
Designed Discharge at M.W.L : 7,90,000 Cusecs
Gross Capacity at FRL in TMC : 77.988 TMC
Water spread area at FRL (Sq.Km.) : 212.285
Water allocation : 60.892 TMC
Average Monsoon rainfall : 1031.76 mm
FRL/MWL : +100.58M/+101.80M
Gross storage : 77.988 TMC.
Dead Storage : 7.567 TMC
Live storage between MDDL&FRL : 70.421 TMC
Budget for the Year 2015-16 : Plan – 124.9800 Crs.
Irrigation Potential: :

The total ayacut contemplated under the Project is .4,05,500 acres wet (stabilization) and 1, 79,000 acres (New I.D) ayacut.

Component Works :
a) Earth Dam :
i) Type of dam : Zoned Earth Dam
ii)Total Length : 352 Meters
iii)Top width : 18 Meters
b) Non Over Flow Dam :
i) Type of dam : Masonry Gravity
ii) Total length : 172.53 Meters
iii) Top level : 105.15Meters
c) Spill Way :
i) Type of Spill way : Ogee Type
ii) Total Length : 236.21 Meters
iii)Crest level : 86.87 Meters
d) No.of Gates : 12 Nos.
Size of the radial gates : 15.24 x 14.17 meters
e)Maximum Designed Discharge : 6, 95,000 C/s at F.R.L.100.58 meters. 7, 90,000 C/s at M.W.L.101.80 meters
Irrigation Potential:

The total ayacut contemplated under the Project is .4,05,500 acres wet (stabilization) and 1, 79,000 acres (New I.D) ayacut.

The Mandals covered are Alluru, Bogolu, Buchi, Dagadarthi, Indukurpet, Kovur, Kodavalur,Muthukur, Nellore, Sangam, Thotapalli Gudur, Venkatachalam, Vidavalur, Podalakur, Nellore Rural, Manubolu, Jaladanki, Kaligiri, Kavali, Kaluvoy, Chejerla, Podalakur, Ananthasagaram, Atmakur, Marripadu and A.S.Peta.