A preliminary report of underwater survey submitted by the Central Soil and Material Research Station (CSMRS) has revealed that the Hirakud Dam is safe, said the dam’s Chief Engineer Biswajit Mohanty on Tuesday.
The final report of the survey is, however, expected around the end of May, he said added.
The preliminary report further makes it clear that the Hirakud Dam is in a better condition compared to similar dams built earlier across the country. Besides, the grouting undertaken to close the gap in the dam is also intact.
The survey was conducted in two phases. While the first round of survey was carried out in December last year for two spillways, the second one was carried out between March 15 and April 5 this year for the dam built with stones.
Notably, cracks and small holes were identified at the spillways during an underwater survey in 2002-03. A whopping 212 pressure release holes at the 497th feet of the foundation gallery were also discovered. While some holes were repaired at that time, many of them remained giving rise to fear that these holes might develop larger cracks.
It may be noted that the 59-year-old dam’s water storage capacity has been on a steady decline because of silt that comes along with floodwaters.
As per a study conducted in 2000, the death storage capacity of the reservoir (below 590 feet) has gone down by 53.7 per cent and life storage (between 590 and 630 feet) has gone down by 17.16 per cent because of siltation.
Overall, the storage capacity of the reservoir has gone down by 27.57 per cent.