Structurally stong: Medigadda, Annaram, Sundilla barrages withstood heavy floods to Godavari in 2019,2022

HYDERABAD: The Medigadda barrage which is a part of the Kaleshwaram Lift Irrigation Project (KLIP) withstood heavy floods twice after the project was dedicated to the nation.

Three barrages were built at Medigadda, Annaram, and Sundilla between August 2016 and June 2019. The designs were approved by the Chief Engineer of the Central Designs Organisation in Irrigation & CAD Department and different construction companies built them as per the approved plans.

The barrages were designed to handle maximum flood discharges of 80,000 cumecs (1 cubic meter/second is equal to 35.314666212661 cusecs), 65,000 cumecs, and 57,000 cumecs respectively. However, in November 2019, due to heavy rains in the upper catchment of the Godavari River, the Kaleshwaram project received heavy floodwater.

To manage the heavy inflows, project engineers opened the 85 gates to release water downstream. However, when the gates were closed afterward, it was discovered that the concrete covering, parts of the curtain walls, and CC blocks constructed on the downstream side were washed away.

The National Dam Safety Authority (NDSA) and the Vigilance reports now pointed out that the floodwaters directly fell outside the apron of the Barrages, displacing the CC blocks and causing the piping or sand boiling effect. They presented proof of the displaced CC blocks with the help of aerial shots at the Chief Minister’s media tour to Medigadda. Hence, none of these issues were directly related to the quality of construction of the project, but issues of maintenance before and after monsoon or the flooding season.

Then again in 2022, due to the torrential rains that battered Telangana, the River Godavari inundated the most important pump houses of the KLIP. An inflow of 22,15,760 cusecs entered into Medigadda barrage due to which all 85 gates of the Barrage were opened, and the flood water was released. While 14,77,975 cusecs of water entered into Annaram Saraswati Barrage where the authorities lifted the 62 gates, releasing the water downstream.

Chief Minister Revanth Reddy, who was then the TPCC chief and the then BJP state president Bandi Sanjay slammed the KCR Government and said that water could not be lifted from Kaleshwaram for another three to four years as all the lifts and pumps were submerged in water everywhere. However, engineers proved both of them wrong, completed the repair work, and ran the pumps successfully.

Floods, a natural phenomenon

Floods are a natural phenomenon. Projects built on the Rivers and pumphouses next to rivers are designed in a way to withstand the test of time. After floodwaters recede, the experts repair them immediately, so they can get back up and running in no time.

• Floods are a natural phenomenon.

• Its nature’s fury

• These are kinds of floods once in 100 years.

• River Godavari and its tributaries were in spate because of heavy rains.

• Medigadda, Annaram, and Sundilla withstood the heavy flood flow, showing no structural stress.

• Pump houses get submerged in such scenarios. These are common and there is no big problem arising out of it.

• In the past, the underground Srisailam hydroelectric station and Kalwakurthy pump houses were submerged.

• They were brought back to work in no time.

• Senior engineers and experts say that the submergence of pump houses like Kannepalli and Akkaram is common.

• In Srisailam the hydroelectric station submerged twice, in 1998 and 2008.

• Kalwakurthy pump house also sunk twice.

• In Uttarakhand in 2009 the Koteshwar hydroelectric project and Chutak hydropower station in Kargil of J&K in 2004 also got submerged.

• In the past Kalwakurthy was brought back to work in just one month

Recurrence and recuperation

Untimely floods do damage property both human and material. Projects built to store and pump water will also get damaged during heavy floods. In this case, Medigadda, Annaram Sundilla barrages withstood the floods in 2019 and again in 2022. However, they showed no structural strain, except for shifting of the CC blocks opening up the soil. NDSA experts will have to study the impact of the displacement of CC blocks on the foundation of these barrages. About the pumphouses, the repairs were undertaken immediately by the contractors as it was covered under the agreement.