Khadakwasla Dam is a dam on the Mutha River from the centre of the city of Pune in Maharashtra, India. The dam created a reservoir known as Khadakwasla Lake which is the main source of water for Pune and its suburbs.
In the vicinity of Khadakwasla Dam is the National Defence Academy (NDA), the Defence Institute of Advanced Technology (DIAT), the College of Military Engineering, Pune (CME, Dapodi) and Central Water and Power Research Station (CWPRS). A few kilometres to the south lies Sinhagad Fort; the twin dams of Panshet and Varasgaon, which mainly supply water for irrigation but also feed into Khadakwasla Lake, lie just due west of the backwaters of Khadakwasla Lake.
Khadakwasla Dam burst at 7:30 am on 12 July 1961, causing the greatest ever disaster to strike Pune. It was not blown up, as some have been led to believe, it simply collapsed at the point of greatest impulsive force, unable to withstand the destructive forces generated by three times the quantity of water gushing in from upstream than it was meant to store at peak capacity as placid water.
Design
The Khadakwasla Dam is long. The dam has been built on the Mutha River, which begins from the confluence of the rivers Ambi and Mose on which the Panshet and Varasgaon Dams are built respectively, and the outflow from Temgarh Lake through Temgarh Dam about north of Varasgaon Dam into Khadakwasla Lake. Mose river has been referred to as Mutha river and shown as such on some maps. The length of the Khadakwasla backwaters is nearly and the width varies from . The maximum depth in the lake is . The dam has 11 radial type sluice gates and six irrigation outlets, flowing into two canals as explained below. Of the three feeder lakes, Varasgaon is the largest, followed by Panshet and Temgarh, in that order. The source of Panshet is close to the base of both Rajgad and Torna Forts and Panshet is the highest of the three, some higher than Khadakwasla. Varasgaon Lake is at the same level as Khadakwasla, and only water released deliberately moves into the Mutha, and then, on to Khadakwasla. Fort Rajgad does not reach the imposing height of Sinhagad Fort, stopping at 2851 feet above sea level.
The Panshet reservoir has a capacity of 2.70 million cubic meters, with Varasgaon reservoir, a larger body, having even more. The Khadakwasla Dam was founded on hard rock. It had a height of above the river bed, with a depth of foundation. Its crest length was and has a free board of . The dam had a flood capacity of 2,775 m3/s and a reservoir of 2.78 million cubic meters. It cannot accept water from both Panshet and Varasgaon together, unless its sluice gates are fully open, causing an overflow of water into Pune, which would perforce allow the waters to end up in the Bhima River and add to water in reverse flow into the Mula River coming East all the way from Mulshi Lake and Dam south of Lonavla, a hill station some west of modern Pune. The plan envisaged control of these three dams to benefit the rapidly expanding city of Pune. The original dam, built in 1879 as a masonry gravity dam founded on hard rock was the first of its kind in the world. This dam was designed by Sir M. Visvesvaraya.
Many people come here on weekends and during the monsoon season. Scenic places around the dam include Peacock Bay, Kudje village and Neelakantheshwar (नीलकंठेश्वर), located near Bahuli village just past Kudje. The Sinhagad road, bordering the dam, has become a favourite picnic spot. There is a "Chowpatty" offering snacks, fast food and non-alcoholic drinks. Peacock Bay, however, is out of bounds to the public at large, being part of the NDA, a Defence Forces establishment.
Water Quality
The backwaters of Khadakwasla Lake, right up to Panshet, Temgarh and Varasgaon dams and lakes, as well as the water in the Ambi/Mutha/Mose river/rivulet do not pass through tenanted areas, limiting induction of pollutants to natural levels. There is no discharge of effluents into these water bodies yet. Filtration of such water is therefore easy and the establishments around Khadakwasla Lake get potable water without much effort. In fact, Lavasa minicity, which was being built on the northern fringe of Varasgaon lake had its construction halted by the Bombay High Court on 7 December 2010, due to its proximity to the lake as it was feared that it could lead to progressive contamination of the water supply to Pune. The dams on the lakes are now turning into tourist spots and the outgoing water might suffer a drop in quality, unless controlled.