At 100, Osmansagar’s tide hits an ebb

HYDERABAD: The picturesque

Osmansagar

, an engineering and architectural marvel, has turned 100. While it should have been an event for Hyderabadis to rejoice, ironically the reservoir across the river

Musi

has fallen on bad days in its centennial year.

Osmansagar was built in 1920 by the Nizam VII, Mir Osman Ali Khan, as part of the two-pronged strategy of engineer-genius Sir Mokshagundam Visvesvaraya to tame floods in Musi and provide drinking water to a million people in Hyderabad.

The foundation stone was laid by the Nizam on March 23, 1913, and the lake was ready, brimming with water in 1920. The Nizam VI, Mir Mahbub Ali Khan, had conceived the project soon after the devastating deluge in 1908 that had killed about 50,000 people (reported by Los Angeles Herald in its October 2, 1908, issue). The flood had affected over 4 lakh people and caused financial loss of Rs 20 crore, which, if compared to present-day price of gold, would be Rs 6.05 lakh crore. The devastation was huge and human bodies lay strewn all over.

The deluge was the result of unprecedented rainfall over a catchment of 860 square miles of Musi and its tributary Esi on September 28, 1908. The quantum of rainfall recorded at Shamshabad, where a rain gauge was available, was 12.8 inches in 24 hours and 18.90 inches in 48 hours. The flood discharge was 4.25 lakh cusecs and the narrow Musi could not withstand the flash flood, resulting in unprecedented death and destruction in Hyderabad.

The construction of Osmansagar had prevented flash floods in Hyderabad in the last 100 years. The occasional flooding in the city is not due to overflowing of the Musi, but encroachments on channels that drain the rainwater into the numerous lakes dotting the city and ultimately into Musi.

INTACH Hyderabad convener P Anuradha Reddy says Osmansagar is not a mere water body, it is part of the engineering and architectural heritage of the princely Hyderabad state. The survival of Osmansagar is essential for Hyderabad for many reasons. Apart from its environmental charm and benefits, Osmansagar is part of Hyderabad’s hydrological cycle. It was one of the biggest structures built in the British India. “Osmansagar is an engineering marvel. It speaks volumes of the genius of the father of Indian engineering,

Sir Visvesvaraya

, who took care of every detail of the dam. We presented the lake with INTACH award not only for its engineering superiority but also for the unique hydrological equipment it possesses,” she says.

Unprecedented planning went into the lake design and construction. Material was sourced from a special railway line laid for the project.