Maneri Dam

The Maneri Dam is a concrete gravity dam on the Bhagirathi River located at Maneri, 8.5 km east of Uttarkashi in Uttarkashi district, Uttarakhand, India. The primary purpose of the dam is to divert water into a tunnel which feeds the 90 MW run-of-the-river Tiloth Power Plant.

Background
The power station is stage one of the Maneri Bhali Hydroelectric Project which was planned in the 1960s. It was completed and commissioned in 1984. Dharasu Power Station, the second stage, was halted in 1990 due to funding issues and was not restarted until 2002. It was eventually completed and commissioned by 2008.

Design and operation
The Maneri Dam is a 39 m tall and 127 m wide gravity dam with a structural volume of 13700 m3. It's spillway is located on its crest and is controlled by four tainter gates. In addition to discharge tunnel, the spillway has a maximum discharge capacity of 5000 m3/s. The dam's reservoir has a 600000 m3 capacity, of which 510000 m3 is active (or "useful") capacity. Water supplied to the power station is first diverted from the Bhagirathi River by the dam into a 8.6 km long tunnel directly behind the dam. The difference in elevation between the barrage and the power station affords a design hydraulic head of 147.5 m and gross head of 180 m. Near the Tiloth Power Plant, the tunnel splits into three penstocks to power each of the three 30 MW Francis turbine-generators before being discharged back into the river. The design discharge of the power station is 71.4 m3/s.