With the rapid depletion of river and ground water levels, floodplains are being seen as a sustainable source of drinking water.
Floodplains have suddenly come into sharp focus with conservationists and experts raising a hue and cry over their destruction. The heavy fines imposed by the National Green Tribunal (NGT) on the Art of Living Foundation for polluting the floodplains of the Yamuna River have also brought them in sharp public focus.
One of the main contentions in the petition filed against the Andhra Pradesh Government in the NGT is that the State is destroying environment by building the new capital on the floodplains of the Krishna River.
Theoretical Physicist professor Vikram Soni, who is doing work on developing cities that do not require huge inputs to sustain themselves, told The Hindu that most of the groundwater had been exhausted and less and less river water was available. Floodplains were a new source of clean water. Over 30 million years, rivers deposited alluvium mostly sand as they keep changing their course to form floodplains. These plains therefore had the capacity to retain more water and also had the capacity to get recharged comparatively fast, he said.
Regular sand would get saturated up to 50 per cent, but the holding capacity of these plains was about 35 per cent. It was possible to pump out only 12 per cent of the water from them, but they would be able to replenish naturally only two per cent of what was pumped out in a year. Therefore only two per cent of the estimated capacity should be utilised. Amaravati could draw 150 million cubic meters (MCD) a day from the Krishna River floodplains, Prof. Soni said.
Water was pumped from several wells with the use of water sensors, he explained.
Instead of using the floodplains for commercial activity, it should be used for the cultivation of organic vegetables and fruits so that the water source was not contaminated, he said.
The city could be planned like a chessboard allotting the black squares for buildings and the white squares for greenery. This would take care of the farmers and agricultural workers who would otherwise be displaced, Prof. Soni explained. This would result in green convection currents in which air from the cooler vegetation would blow on to the buildings which were a couple of degrees warmer.
Over and above the green convection currents, there would be blue convection currents from the river water on to the land, he said.
Amaravati was a unique opportunity to use more sustainable and sophisticated ways of building a new capital. Delhi Minister for Water and Tourism Kapil Mishra, who was so impressed by the “Yamuna floodplain water project” at Palla when he visited it on Wednesday, said he would invite Andhra Pradesh Chief Minister N Chandrababu Naidu to see for himself the benefits, said Prof. Soni who is also Delhi Jal Board member.
Social activist Satya Bolisetti said many were not aware of how sophisticated, non-invasive and perennial source of water floodplains were.
However, the plans proposed by various consultants for building the Capital that were under the consideration of the State Government were “archaic” and “unsustainable”, said Prof. Soni and Mr. Satya.
