Sangam anicut was constructed across Penna river during 1882-1886 contemplating to supply water to Nellore tank supply channel and Kanupur canal on right side and Duvvur canal, Kanigiri main canal and Kavali canal on left side. This anicut is the life line for the irrigation of about 3.85 lakh acres now being irrigated. The following are the details of ayacut fed with the water from Somasila reservoir.

1) Penna delta : 2.47 lakh acres
2) Kanupur canal : 0.63 lakh acres
3) Kavali canal : 0.75 lakh acres
Total : 3.85 lakh acres

Sangam anicut was constructed across Penna River during 1882-1886

During course of time thousands of acres of additlonal ayacut was brought into cultivation. It has became a regular practice to increase the water level by 0.90 mtrs., above crest level of Sangam anicut by providing sand bags of 1.20 mtrs., height over the crest for the entire length for providing commandability to the existing ayacut under Kanupur and Kavali Canals. This practice of placing the sand bags over the crest of anicut is resulting in recurring cost in lakhs of rupees for Government every year. Unless the anicut is replaced by a new one, the anicut is likely to prone for breaching due to over age (crossed 100 years).

Salient Feature
Catchment area : 50,122
Maximum flood discharge : 21240 cumecs
Flood discharge : 1382 cumecs
F.R.L.(pond level) : + 35,000 meters
U/S maximum water level 21240 cumecs : +39.460 meters
U/S MWL For 13182 cumecs : + 37.461 meters
Crest level of barrage : + 32.200 meters
Crest level of scour sluice : + 31.200 meters
Up streem side floor level : + 31.000 meters
Down streem side cistern level : + 28.970 meters
No and size of vents (Barrage) : 54 Nos. of 12.00 MtrsX2.80 Mtrs
No and size of vents (Scour Sluice) : 6 Nos.(3+3) of 12.00 MtrsX 3.80 Mtrs
Thickness of intermediate pier (Barrage) : 2.00 Mts.(under hoist bridge)
Thickness of Intermediate Pier (Barrage) : 1.20 Mts.(under road bridge)
Type of gates : Vertical Lift
Length of barrage : 846 meters
Pounding capacity : 0.450 TMC
Flood bank left side : 4.00 kms
Flood bank right side : 3.00 kms
Bund level U/S (afflux) : + 40.960 Mtrs
TBL D/ bund : + 38.250 meters
Hoist plat form level : + 43.500 meters
Road Level : + 40.960 meters
Irrigation Potential :
No. of mandals covered : 5 Nos
No. of villages covered : 72 Nos
Ayacut : 1,50,000 acres