The Threat of Piping and Seepage at the Dam's Foundation

R.P.Kulkarni, in his article 'Irrigation Engineering in India' has surveyed the engineering history of masonry dams in India including Periyar Dam (height 45 m).  He mentions thus: " It may be noted that almost all these (masonry) dams have served well without any mishap but their sections are found to be inadequate according to the modern theories."

He points to the dangers of 'piping' or the process by which water percolating under a dam has sufficient pressure and velocity to erode the foundations and undermine the dam's structure.  This was noticed in the Coleroon dam built in 1836 by Arthur Cotton, another British Engineer.  He further says, "Similar failures of other Indian river dams eventually led to the first experimental investigations of seepage under masonry dams, and the work of Beresford and Clibborn in the 1890s was able to predict the failure in 1898 of the Narora weir on the river Ganges."

The question that arises is:
Have there been investigations and monitoring of  piping along with seepage under the Periyar dam's foundation so far?
-Joseph Ponnoly

Reference:
Kulkarni, R.P. Irrigation Engineering in India. Indian Journal of History of Science, 17(1); 28-45
http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005af6_28.pdf