Water entered the main hall, holding room, air conditioning system room and studio of Metro FM, which is on the ground floor of the City Hall.
According to KMC officials, water had flowed in from the ground as well as the roof of the structure, causing damages to furniture.
"As the renovation was carried out hastily for the Summit, many technical errors during the construction were overlooked. The water that accumulated on the City Hall premises entered the ground floor. Likewise, water also leaked from the roof," said Sanat Kumar Thapa, chief of the City Hall.
"A pump set of the KMC was used to remove water from the building. Although the water did not cause any significant loss, if the buildings are left in the same condition till monsoon, there will be huge property damage," added he.
After water entered the studio of Metro FM, KMC was forced to stop broadcasting its radio program.