Inchampalli-Pulichintala Link
Godavari (Inchampalli) - Krishna (Pulichintala) Link forms a part of the scheme of transfer of surplus waters of Mahanadi and Godavari rivers to the deficit basins of Krishna, Pennar, Cauvery and Vaigai. The link scheme is an important part of various proposals under the Peninsular Rivers Development Component of National Perspective Plan. The project comprises of the following components:
- A storage reservoir on Godavari river at Inchampalli with FRL 112.77 m, gross storage capacity of 10374 Mm3 , live storage capacity of 4285 Mm3 and minimum draw down level of 106.98 m.
- A lined conveyance system of length 312.20 km from Inchampalli dam to Pulichintala reservoir (including a tunnel of 12.5 km length for crossing the ridge between Godavari and Krishna basins).
- The proposed Pulichintala dam with FRL 53.34 m, MDDL 42.7 m and live storage capacity of 1296 Mm3
The link canal is designed as lined canal of trapezoidal shape with bottom rounded corners. The maximum carrying capacity of the canal is 304 cumecs with the corresponding cross section of 33.4 m of bed width and 6.0 m full supply depth. The tunnel is designed to have 13 m dia. The canal passes through forest patches and agricultural lands comprising forest soils, red earths, black cotton soils and red soils.
The link canal takes off from the right flank of the proposed Inchampalli dam with FSL 106.68 m and traverses for a length of 312.2 km (including 12.50 km long tunnel proposed to cross the ridge between Godavari & Krishna basins) through Karimnagar, Warangal, Khammam and Nalgonda districts of Andhra Pradesh.The link canal is supported by number of branch canals of which NSLBC feeder branch taking off at RD 200.00 km by a lift is significant. The multiple reservoir simulation carried out for the Bhopalpatnam & Inchampalli reservoirs shows that the demands are met with a success rate between 76% and 80% for various purposes. Since the topography doesn’t permit the gravity flow irrigation throughout canal system, lifting arrangements are provided on link canal at RD 200 km to feed the existing NSLBC and on the right flank of Pulichintala reservoir. The total pump capacity required is 112 MW and the annual power requirement for these lifting arrangements works out to 285 MU.
Godavari (Inchampalli) – Krishna (Pulichintala) link project envisages diversion of 4370 Mm3 of water from the proposed Inchampalli dam on river Godavari to the proposed Pulichintala reservoir on river Krishna. Out of this, a quantum of 3665 Mm3 is earmarked for irrigation, 413 Mm3 is planned to be utilized for municipal & industrial purposes in the command areas and the urban areas en route the link canal up to 20 kms. and the remaining 292 Mm3 will be lost in transmission.
It is proposed to bring 445299 ha of CCA under irrigation, comprising proposed command of 85230 ha(IRBC 48230 ha, command area of 37000 ha under NSLBC beyond Tammileru) and existing command taken over by link canal to the tune of 360069 ha (NSLBC 156700 ha and NSRBC 203369 ha).
Apart from irrigation, it is also proposed to cater to the future municipal and industrial water requirements in the command area as well as all the townships along the link canal up to 20 kms. About 41 lakh human population and the industrial water requirements by 2050 AD are proposed to be served utilising 176 Mm3 and 237 Mm3 respectively. Further, it is proposed to tap the power potential available through the spills from the Inchampalli dam. A powerhouse with effective capacity of 825 MW with reversible turbines is proposed for this purpose to generate 2477 MU annually. To facilitate the pumping of water into reservoir, a pond is proposed with storage of 34.2 Mm3 on the downstream of the dam. In addition, three canal powerhouses with effective capacity of 9 MW in each power house are also proposed to generate 110 MU annually through the cascade of falls available on link canal before its outfall into Pulichintala reservoir.
The cost of the project is estimated to be Rs.5046 crore, which includes the apportioned cost of head works at Rs.306 crore, the cost of conveyance system at Rs.4252 crore, the cost of power component at Rs.53 crore, the cost of lifting arrangements at Rs. 409 crore and cost of on farm development at Rs. 26 crore. The annual cost after duly considering the land development and the annual power requirement for lifting works out to 646 crore. The direct benefits from the link project due to irrigation, municipal & industrial water supplies and power generation are estimated to be Rs.2202 crore.
The benefit-cost ratio (BCR) of the project works out to 3.41 whereas the internal rate of return (IRR) works out to 19.26 %.
