The above titled letter of Khurshid Anwer in the Nation of June 24 contains some useful information which is not generally known. It should not be just read and put aside. The information needs to be stored and used in the debate for the construction of Kalabag Dam. The subject of power and water is of vital importance to the country and deserves special attention of your esteemed paper. NAELA AAMIR, Lahore, June 26.