Among the many regional flood relationships for computation of mean annual flood for non-snow fed and upstream storage free catchments in India, the relationship developed by Swamee et al. (1995) is considered to be more general and dimensionally correct and to satisfy the boundary conditions and have the least average error. However, the average error associated with Swamee et al. (1995) relationship is considered large and its evaluation and possible improvement is, therefore, desirable. A modified functional relationship for the flood is proposed considering length of main stream as an additional variable. It is observed that consideration of length of main stream as an additional parameter in the flood relationship leads to distinct improvement in the calibration of flood values and is more general in nature.
