Storage reservoirs and overhead tank are used to store water, liquid petroleum, petroleum products and similar liquids. The structure analysis of the reservoirs or tanks is about the same irrespective of the chemical nature of the product. All tanks are designed as crack free structures to eliminate any leakage This project gives in brief, the theory behind the design of liquid retaining structure (Elevated circular water tank with a domed roof and conical base) using working stress method. Elements are designed in limit state method. Liquid tanks and especially the elevated tanks are structures of high importance which are considered as the main lifeline elements that should be capable of keeping the expected performance. An earlier design of water tanks being done using the working stress method given in IS 3370: 1965. This method leads to thicker and heavily reinforced section. The use of limit state method of design has been adopted in received code IS 3370:2009 and provision for checking the crack width is also included in this code.