The National Green Tribunal (NGT) recently made news when it established a high-level committee to identify the floodplain zones of the Mahanadi River, the largest river in Odisha. The decision is seen as a vital step towards protecting the river’s ecology and managing its flow.
Background
In January 2020, Odisha’s Chief Minister declared that 424 acres retrieved from the Mahanadi River would be employed for enhancing ecological, recreational, sporting, cultural and technological values for Cuttack’s residents. However, this plan was contested by a local resident who petitioned to the NGT, alleging that these illegitimate construction activities could harm the river’s ecology and disrupt its flow pattern.
NGT’s Response
The NGT responded to this concern by assembling an expert panel from the Central Water Commission, National Institute of Hydrology, and state and central pollution control boards. Their task is to enact regulations ensuring that the riverfront development proceeds without causing harm to the river’s floodplains.
Legislation to Regulate the Flood Plains
There is no national legislation governing the flood plains at present. The only existing provision is a 2016 notification from the Ministry of Water Resources, River Development, and Ganga Rejuvenation. This rule, part of the Environment (Protection) Act, 1986, forbids any construction activity in the active floodplain area of the River Ganga or its tributaries. However, some states have enacted their legislation to oversee flood plains, including the Manipur Flood Zoning Act, 1978 and Uttarakhand Flood Plain Zoning Act, 2012.
Understanding Floodplains
A floodplain is a low-lying area next to a river, primarily formed by flooding and deposition of sand sediments. These sandy areas are exceptional aquifers, with withdrawal compensated by gravity flow from a larger surrounding region. Some floodplains, like the ones belonging to Himalayan rivers, hold up to 20 times more water than virgin river flow during a year due to rain and late floods.
About the Mahanadi River
After the Godavari and Krishna rivers, the Mahanadi River system is the third largest in peninsular India, and the largest in Odisha. Its origin is near Sihawa in Bastar hills, south of Amarkantak, in the state of Chhattisgarh. The river has several major tributaries including the Seonath, Hasdeo, Mand, Ib, Jonking and Tel rivers.
The Mahanadi River Basin
The catchment area of the Mahanadi river extends over several states, including Chhattisgarh, Madhya Pradesh, Odisha, Jharkhand and Maharashtra. This basin is flanked on the north by Central India’s hills, the Eastern Ghats on the south and east, and the Maikala range on the west.
