Hussainsagar warnings ignored

Ten years after the proposal to construct flood gates for the Hussainsagar was mooted, it still remains a proposal. Flood management, irrigation and urban development experts say it is dangerous to assume that there will be no floods in the lake, particularly since the change in the rainfall pattern worldwide as well as in the city and state has led to increased precipitation.

Flood gates will help regulate outflow of water whenever there is heavy inflow from the catchment area. The full tank level (FTL) of the lake is 513.41 ft and heavy rains in its catchment area in August and September saw water flowing over the FTL.

However, experts made it clear that the flood gates will not help in improving or fortifying the over 400-year-old lake and its bund, but will mainly prevent inundation of areas up and downstream of the lake. Since these are populated areas - the government having failed to evict encroachments - this is an important consideration.

Eminent irrigation expert, Mr G. Prabhakar, who also heads the Institution of Engineers at the national level, said the 240 sq km catchment of Hussainsagar has wide vulnerability of flooding the lake and areas upstream. should there be heavy rainfall in parts of Ranga Reddy district. The flood gates project was mooted after the residential areas upstream and downstream of the lake were submerged in the devastating floods of 2000 that left a trail of destruction in the city.

“In the wake of climate change resulting in high intensity rains during a short period of time, the flood gates are needed at Hussainsagar. Construction of the gates will be a one-time investment and will help in preventing breaching of the tank and inundation of residential areas upstream and downstream. It is always advisable to have flood gates for a water body like the Hussainsagar as its periphery is encroached upon by residential and commercial buildings,” Mr Prabhakar said.

Hussainsagar does not have flood gates but it has vents on the Hotel Marriot side and also at the GHMC head office building side. When water reaches FTL, it flows out through these vents into the Hussainsagar surplus nala. During heavy rains, the areas downstream of the lake get inundated. And, if the inflows are heavier compared to the discharge capacity of the lake, areas located upstream too will get marooned.

The proposal, therefore, is to construct flood gates at a much lower level than the lake’s FTL of 513.43 ft. The project was estimated to cost `9 crore originally, but will now cost more than `35 crore.

The irrigation and flood management expert, Mr T. Hanumanth Rao, says the flood gates are necessary to protect the lives and properties of families living in the houses that are encroaching along the lake area. Erecting the flood gates — if it ever happens — is not enough. The government must protect the lake area from further encroachments.

Some attempt is being made to limit inflows into the lake. Mr V.L.N. Reddy, executive engineer, HMDA, said the Hussain Lake Cleaning and Improvement project will stop sewage and industrial effluents flowing into the lake and allow only water from storm water drains into the lake. But there will be heavy inflows in the lake during the rainy season and it is always better to have flood gates to better control the water level in the lake.

The construction of the flood gates will require some clever traffic management.

The additional commissioner of police, traffic, Mr C.V. Anand, says Tank Bund is a high traffic density corridor as it connects the new city with the old city. Traffic will have to be diverted at the Hotel Marriot point on Tank Bund. 

“From the traffic point of view, it will be a difficult assignment. There are two alternative routes, one via Necklace road and the other via Lower Tank Bund road. A lot of studying and planning will have to be done if traffic has to be stopped on Tank Bund,” he said.

The GHMC engineer-in-chief, Mr Panduranga Rao, says that though the flood gates project has been delayed, the government is now moving swiftly to execute the project.

Pic Caption:
Water overflows from the Hussainsagar flooding the areas near Hotel Mariott. It is always advisable to have flood gates for a water body as its periphery is encroached upon by residential and commercial buildings.