Constructing the country’s 6th biggest reservoir, the lower Malwathuoya, will begins tomorrow at 9.36 am. It will cost the government Rs. 23,000 million.President Maithripala Sirisena and Prime Minister Ranil Wickremesinghe will be the chief guests at the foundation stone laying ceremony. The proposed reservoir near Thanthirimale will contain 170,000 acre feet of water.