Demand - Supply Incompatibility of Irrigation Water of an Irrigation Project with Unusual Command Area-Catchment Ratio

It is observed that ratio of command area to catchment of existing irrigation project in India normally varies from 0.3 to 0.5. FAO Corporate Document Repository, in their document “Design model Catchment: Cultivation area ratio”, shown the ratio as 0.14 for arid region and 0.31–0.54 for semi-arid region. But in case of Salandi Irrigation project, Odisha (India), the said ratio is 1.276, which is extraordinary. The crop water requirement in command works out to 0.858m in Kharif and 1.296m in Rabi. It is found that the actual water supplied in the distribution system for the period from1985-86 to 2005–06 during Kharif and Rabi is 0.283m and 0.929m, respectively. This less quantity of water supply for irrigation than the theoretical requirement has not affected the crop yield but has made the agriculture successful. Various aspects of the Project such as the geophysical features, hydro-geological formation of the command, soil characteristics, percolation rate through the top soil, amount of rainfall and its distribution, cropping pattern in the command and irrigation practices in the irrigation command and probable reason for success of this project in providing irrigation over the years with less quantum of water has been analyzed and presented in this paper.