The Mahanadi Delta in India is formed by the network of three major rivers: Mahanadi, Brahmani and Baitarini. The delta covers a coastline of 200 km, which stretches from south near Chilika to north upto Dhamra River. The Delta covers an area of 9,500 sq km accounting for a mere 7% of state’s geographical area.
It is the ecological and socio-economic hub of state of Orissa, it supports more than one-third of its population, 68% of which are farmers with similar number falling below poverty line.
Landforms of the Delta
The delta’s landforms are mainly denuded hills and erosion plains, whose depressions contain water bodies. The central part of the delta is distinct for its extensive plains, leeves and paleochannels. The coastal parts contain spits, bars, lakes, creeks, swamps, beaches, tidal flat and mangroves.
Critical conservation areas
Furthermore, the Delta contains critical conservation areas (in particular several freshwater and coastal wetlands) and Biodiversity Hotspots, with a wide range of species including rare and threatened ones. Moreover, they are the source of a range of ecosystem services critical to ecological and economic security of the region.
One of the Delta’s highly critical conservation areas are Chilika Lake, the largest brackish water lagoon; Bhittarkanika, a mangrove forest with high species diversity; and Garimatha, habitat of Olive Ridley turtles and the largest rookery in the world.
Rich in biodiversity
As it’s situated at the end of the migratory Palaearctic flyway, a total of 211 bird species have been identified at Chilika, of which 97 are intercontinental migrants. Additionally, the lake also supports a very healthy population of Irrawady Dolphins. A recent survey estimated the current population to be over 110 individuals, making it probably the world’s largest Irrawady Dolphin population.
Lacking hydrogological management
The wetlands of Mahanadi are governed by the hydrological regime of the delta. Nevertheless, the water management interventions undertaken have been sectoral in nature and focused mainly on structural approaches without considering the hydrological, ecological and socioeconomic set up of the delta in general and wetlands in particular.
As a consequence, the delta is marked with persistent water logging, low agricultural productivity, loss of migratory fisheries, declining incomes, social conflicts, migration and health hazards due to limited availability of safe drinking water and sanitation. Changing rainfall patterns and increased frequency of extreme hydrological events attributed to climate change are inflicting added vulnerabilities to livelihoods and resources.