Thiruvananthapuram: Tamil Nadu is preparing for pressure grouting to strengthen the more than 125-year-old Mullaperiyar dam.
The haste being shown by Tamil Nadu to carry out the pressure grouting despite reassurances from many quarters that the dam is safe has raised concerns in Kerala.
Tamil Nadu has not clarified whether more cracks have formed in the dam or if it has developed leaks. It plans to carry out pressure grouting in two phases at a cost of Rs 10.07 crore in the dam that has a storage capacity of 152 feet.
Pressure grouting will be carried out till the level of 130 feet in the first phase and then above this till the level of 152 feet in the second stage.
Tamil Nadu decided to carry out pressure grouting after a study report submitted by Central Soil and Materials Research Station officials who had visited the dam in May 2015. It has sought permission for pressure grouting from the supervisory committee appointed by the Supreme Court for Mullaperiyar. It plans to complete the pressure grouting process by May if it committee grants the requisite permission.
Reinforcement of the dam by grouting is done when the amount of water (seepage) coming from the dam to the gallery increases drastically or when the amount of dam building material (surki mixture) flowing through the seepage water increases.
What is pressure grouting?
Pressure grouting is the process of making holes (boreholes) in the wall of a dam and then injecting cement grout through it with force.
Any leak in the dam can be temporarily controlled with this. However, experts point out that if the existing cracks in the dam are not completely closed and grouting is done by making holes in the wall, the cement mixture will leak out through the cracks.
