Discharge coefficient is usually dependent on dimensionless parameters such as Reynold's number and Weber number associated with dynamic conditions of flow over the structure, and ratios of weir, notch and flume dimensions which reflect variations in the geometrical design of the measuring structures. The data are presented to provide engineers with a means of estimating discharge coefficients for rectangular weirs whether they are flat-topped or sharp-crested. The information contained herein will provide a description of the testing apparatus and the manner in which the discharge coefficients should be used. As part of the research conducted, discharge coefficient scale effects for weir, much data was collected for various flat-topped and sharp-crested weirs & the values for height/width are determined with the help of various methods. These are varied according to the dimension of the weirs & resulted into the small, intermittent and large ones. The material from which the structures are fabricated are obtained cheaply available in the market & the methods which are applied for cutting the structures in specific dimensions are done very easily, such as Gas-cutter method.