<P> WPP units are to be located at the toe of the Nagarjuna Sagar dam with tail water level of 240 feet (73 m) MSL on either side of the river . The WPP units can be connected below 380 feet (116 m) MSL level to the reservoir with the technique called under water reservoir / lake tapping . Under water lake tapping method was implemented successfully in Koyna Hydroelectric Project to install additional hydroelectric units without emptying the Koyna reservoir . The cost would be Rs 15 billion for utilizing 150 TMC storage additionally . If the same storage is created under a new reservoir, it would cost not less than Rs 200 billion . Water can be supplied to high level canals at sill 580 feet (177 m) MSL on both right and left banks without consuming electricity with WPP units to irrigate dry lands further in Nalgonda, Warangal, Khammam, and Guntur districts . As a further cheaper solution to utilise the available dead storage water partially (up to 50 TMC), the existing river chutes available on both sides of the dam at sill level 450 feet (137 m) MSL, can be used for providing water supply to the WPP units without the need of lake tapping . There is no need of lake tapping on the left bank side and the existing river diversion tunnel can be used to supply water to the WPP units for pumping water into Nagarjuna Sagar left canal . This option is best suitable for feeding the right canal as it is not consuming any power for pumping water and some water is to be released for Krishna delta needs by AP state . </P> <P> There is a cheaper possibility to pump water into the left canal when the reservoir water is below its sill level 490 feet (149 m) MSL by using the reversible turbines (7 x 100 MW) of existing hydro power station on the left bank of the river . Water would be released into the down stream tail pond through the hydro power station or the existing diversion tunnel . When water is to be pumped into the left canal, the water released into the downstream tail pond is pumped back into a contour canal which connects the hydro power station and the left canal intake point . This contour canal is nearly 10 km long and located inside the Nagarjunasagar reservoir area situated at 510 feet (155 m) MSL . Only three units of the reversible turbines are required to feed nearly 12,000 cusecs water to the left canal at its MDDL level and rest of four reversible units can be used for power generation by releasing water into the tail pond . The pen - stock inlets of the three unit at 125 metres (410 ft) MSL are to be connected with the extension piping (4.8 m diameter) to feed the contour canal at 510 ft MSL . The extension piping is disconnected when water pumping to left canal is not required to restore the hydro power units normal working . When reservoir level is at its FRL level, the canal and the extension piping get submerged under water without undergoing any damage as the contour canal is away from the spillway of the dam or flood flow path . Thus both Telangana and AP states can use the reservoir dead storage water fully to ensure water supply for the command area under the left canal even during drought years . </P> <P> Alternatively, floating / barge mounted pumps can be installed along with associated piping on the reservoir bed to pump water from the reservoir's dead storage into left and right bank canals and the approach channel of the existing pump house of Hyderabad water supply scheme during drought years . During the good monsoon years, when the reservoir water level is above the dead storage level, the same barge mounted pumps can be used regularly to pump water into the existing high level (flood flow) canal (near 16 ° 39 ′ 27" N 79 ° 15 ′ 43" E ﻿ / ﻿ 16.65750 ° N 79.26194 ° E ﻿ / 16.65750; 79.26194 ﻿ (Flood flow canal)) located on the left bank of the reservoir in Nalgonda district . Similarly, during the good monsoon years, a lift irrigation scheme can be taken up with the help of the same barge mounted pumps to lift water from the reservoir (near 16 ° 21 ′ 41" N 79 ° 14 ′ 31" E ﻿ / ﻿ 16.36139 ° N 79.24194 ° E ﻿ / 16.36139; 79.24194 ﻿ (Proposed lift scheme)) by 45 m height for irrigating nearly 200,000 acres of uplands situated adjacent to the reservoir in Guntur district . Thus all the installed barge mounted mobile pump houses can be used for regular pumping needs to maximise the water use from the reservoir every year . </P> <P> Another option is to separate a small portion of the reservoir by constructing a weir up to 510 feet (155 m) MSL along with an underground pumping station at 16 ° 37 ′ 21" N 79 ° 16 ′ 01" E ﻿ / ﻿ 16.62250 ° N 79.26694 ° E ﻿ / 16.62250; 79.26694 ﻿ (Underground pumping station) to maintain gravity flow to the left bank canal side from the lower level dead storage water of the main reservoir . When the reservoir water level is above 510 ft MSL, the weir would get submerged and water flows to left canal without any pumping as usual . </P>

Jawahar and lal bahadur canals of nagarjuna sagar