Explanation:

Department of Water Supply and Sanitation was initially known a Public Health Branch of PWD which came into existence in the year 1956. Prior to that it was functioning as a part of Building and Roads Branch.The department was responsible for all types of Public Health Engineering Works viz. Water Supply and Sanitary installation in Government Buildings/Institutions and Public Health Engineering works in Urban Estate, grain markets etc.In the year 1975, functions of Punjab PWD (Public Health Branch) were vertically split up into three wings viz. Govt. Works, Rural Water Supply Works and Works of Local Body department.
The Govt. Works Wing was responsible for Public Health Works in all Govt. buildings, Urban Estate, Harijan Basties and grain markets etc. Rural Water Supply Wing was responsible for design, construction and maintenance of Rural Water Supply Schemes whereas Local Bodies Wing was responsible for the provision of water supply and sewerage in Municipal Areas.On 1st January 1977, Local Body Works Wing was converted into a Board and named as Punjab Water Supply and Sewerage Board.Subsequently Public Health department was restructured by creating two Rural Water Supply Wings i.e. RWS (South) & RWS (North) and one Govt. Works Wing.At the Secretariat Level Department was under the Administrative Control of Principal Secretary to Govt. Punjab Department of Public Health.The works of the Rural Water Supply wing and Govt. works wing were combined at the level of Superintending Engineer in May, 2003.
Accordingly, the Rural Water Supply Divisions and Govt. works Divisions worked under one Superintending Engineer and the wings of the department were named as WSS (South), WSS (North) and WSS (Central) headed by three Chief Engineers.The name of the Public Health Department was changed to Department of Water Supply and Sanitation in the year 2004.