India, Sept. 6 -- Nearly all major riverfront and biodiversity projects developed by the Delhi Development Authority (DDA) along the Yamuna floodplains now lie under water, with the swollen river surging well above the danger mark for the past four days.

Officials said the scale of destruction will only be known once the water recedes, but vast stretches of newly planted landscape - lawns, ornamental shrubs, saplings and riverine grasses - are feared lost. Walkways, sculptures, parking lots and cycle tracks are also submerged, reducing ambitious floodplain redevelopment projects to waterlogged wastelands.

Among the worst-hit is the Amrut Biodiversity Park, inaugurated in March this year across 90 hectares on the eastern bank near the De...