Hirakud Reservoir, the largest earthen dam in Odisha, constructed across river Mahanadi at Sambalpur, started operating in 1957. The gradient of habitats ranging from riverine to lacustrine, while moving towards the dam, enables the reservoir to support a range of floral and faunal species, including several of high conservation significance. Out of the known 54 species of fish from the reservoir, one has been classed as being endangered, six near threatened and 21 fish species of economic importance. Fisheries presently yield a catch of around 480 MT of fish annually and is the mainstay of livelihoods of 7,000 fisher households. Similarly, over 130 bird species have been recorded at this site, out of which 20 species are of high conservation significance. Hitakud reservoir has been included in the list of prioritized inland wetlands of Odisha (Prasad et al. 2004), and further in the list of Important Bird Areas (IBAs) of the state of Odisha. The reservoir is a source of water for producing around 300 MW of hydropower and irrigating 436,000 ha of cultural command area. The wetland also provides important hydrological services by moderating floods in the Mahanadi delta, the ecological and socio-economic hub of the east coast of India. Hirakud reservoir supports abundant tourism, and forms an integral part of the high touristic value sites located around Sambalpur with over 30,000 tourists annually visiting the site.

A wetland should be considered internationally important if it contains a representative, rare, or unique example of a natural or near-natural wetland type found within the appropriate biogeographic region.

A wetland should be considered internationally important if it supports vulnerable, endangered, or critically endangered species or threatened ecological communities.

A wetland should be considered internationally important if it supports populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region.

A wetland should be considered internationally important if it supports plant and/or animal species at a critical stage in their life cycles, or provides refuge during adverse conditions.

A wetland should be considered internationally important if it regularly supports 20,000 or more waterbirds.

A wetland should be considered internationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of waterbird.

A wetland should be considered internationally important if it supports a significant proportion of indigenous fish subspecies, species or families, life-history stages, species interactions and/or populations that are representative of wetland benefits and/or values and thereby contributes to global biological diversity.

A wetland should be considered internationally important if it is an important source of food for fishes, spawning ground, nursery and/or migration path on which fish stocks, either within the wetland or elsewhere, depend.

A wetland should be considered internationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of wetland-dependent nonavian animal species.