Half of Hyderabad buildings face flood risk: Study

Hyderabad: More than half of the buildings located in the GHMC limits are at high risk of getting affected in the event of floods, according to a flood susceptibility-based building risk (FSBR) under climate change research conducted by the BITS Pilani Hyderabad, in the GHMC area.

The study also predicted an extremely heavy rainfall of 1,740.62 mm, occuring in the year 2040, which is almost eight times more than what the city has received in August 2020 (241.5mm). This has been attributed to drastic climate changes and also the increase in land use.

Buildings and roads have highly susceptible areas of 57.59 percent and 22.76 Sq kms and the inundated area is 442.53 km2 , with flood depth ranging between 0.1–8m, found Dr Madhuri Rampalli, who conducted this study under the guidance of Professors K. Srinivasa Raju and A. Vasan of the Department of Civil Engineering.

She suggested Waterproofing the buildings under the high risk category, diverting the water to resource filtration basins, wells, for ground water recharging, as mitigation measures. The total cost of waterproofing the high risk category buildings is Rs. 4,964.60 cr, the study estimated.

FSBR is a combined index for evaluating flood susceptibility and building risk simultaneously to understand the impact of the flood, according to climate change aspects based on the General Circulation Model (GCM, GFDL-CM3), and Representative Concentration Pathways (RCP 2.6).

For the study, GHMC area was divided into 16 zones and it found the most vulnerable locations to flooding are situated near the Hussain Sagar and Musi River. Kothapet, Mansoorabad, Falaknuma, Kacheguda and Begum Bazar have high percentage inundation areas as they are near the Musi River and exist in low-lying areas.

According to the study, the highest number of High Risk buildings were found in Falaknuma, Kacheguda and Begum Bazar Zones, followed by Kothapet, Mansoorabad zones. Greater number of Low Risk buildings were found in Gachibowli, Vanasthalipuram and Kapra zones as they are at relatively higher elevations.

Chandanagar has the least percentage of inundation area due to its high elevation level. Kukatpally has flood depth of 0.3 - 8m, and Vidyanagar and Ramnagar have flood depths of 0.2 – 6.8m. This is due to rapid urbanization in these zones, the study found.

Meanwhile, Prof Dr D Vijay Kishore from the Jawaharlal Nehru Architecture and Fine Arts University said that in view of the rapid expansion of the city and a new city all together taking shape abutting the ORR towards the west, Government should work in tandem with all stakeholders to come up with an emphasis on underground drainage system, smooth run of surface water and also on the low lying areas. “ We have to see what is happening in Delhi, Mumbai and several other places and prepare a plan for our city accordingly,” he added.

Zones

1 Kothapet, Mansoorabad

2 Hayathnagar

3 Vanasthalipuram

4 Saroor Nagar, Kanchanbagh

5 Falaknuma, Kacheguda and Begum Bazar

6 Attapur, Goshamahal

7 Rajendra Nagar

8 Mehdipatnam, Jubilee Hills, Panjagutta

9 Gachibowli

10 Serilingampally, BHEL

11 Chandanagar

12 Kukatpally

13 Vidyanagar, Ramnagar

14 Kapra

15 Tarnaka, Nacharam

16 Cherlapally

Waterproofing for reducing FSBR:

Waterproofing is the mechanism to restrain the entry of water into the walls and rooftops of a building. It will also increase the life cycle of buildings considerably and employed to reduce the FSBR in terms of the total affected area and the number of exposed buildings