Rainwater stagnates in several parts of the world heritage site every year, causing causes immense damage.
Well-defined structures of old drains were discovered along with certain old artefacts during the digging.
"We had gone just half a metre down the level of surface of the old structures in the DK-G area and found the material of cultural value," The Dawn quoted Moenjodaro director Qasim Ali Qasim, as saying.
An object called 'elliptical lid' was also found and according to Moenjodaro curator Irshad Rid, it was something new for archaeologists.
He said that prior to this digging no such object had been found at any site of the Indus Valley civilisation.
The curator said E J H Mackay did last excavation of the site between 1927 and 1931. Since then, he said, no excavation in this portion had been done.
He said that the new finds could be related to the late period of Moenjodaro. Rid said that the 'elliptical lid' might have been used for keeping 'holy water' or 'ceremonial water'. "A miniature used for keeping medicines was also discovered at the site," the curator said.
He expected to find more remains during the drain digging, as some portions of the defined drain area were low-lying.
The team, he said, would do the digging in an area about 100 feet long with the aim of constructing a drain so that rainwater could be disposed of in the old circular drain.
Also, pieces of charcoal were found which, according to Qasim, would be the authentic source to establish the age of the structures.&13;