Statistical and probability analysis of rainfall occurrences of Nayagarh block of Orissa was carried out for planning and designing of water conservation and recharge structures. This analysis provides the water management group with a substratum to rationally and scientifically plan and design structures that would be location specific and cater to the water management needs of a particular region. Based on this, optimized design of water harvesting structures can be made to maximize water storage capacity and recharge potential.