Regular flood spilling and water, nutrientWetland supply from river to floodplain wetlandFloodplain wetlands continue the eco-hydrological vibration of floodplain ecosystem. Whether damming is anyway caused for interruption in this river-wetlandWetland connection is a matter of concern and this chapter tried to explore this. For this discharge-based 2D inundation, simulation in HEC-RASHEC-RAS was done in case of pre- as well as post-dam. Overlaying of wetlandWetland with regards to the inundation extent in both the hydrological regimes was done in order to classify wetlandWetland’s eco-hydrological stress. Result revealed that in post-dam period, inundation area was decreased 4828–1627.30 km2. Inundation depth was also found significantly declined in parity with flow reduction (66% of peak flow decreased) in Master stream. About 81 km2 (18.8%), 95 km2 (22.1%), and 338 km2 (78.6%) of identified wetlandWetland areas of the post-dam period were recognized respectively as critical, stress, and safe wetland security state (WSSWetland Security State (WSS)). Majority of smaller wetlandsWetland located at the elevated outskirts zones are critical in nature due their location outside the lateral flood limit of pre-dam period. Often these are ortho-fluvial in nature. Comparison between hydrological stability and WSSWetland Security State (WSS) further revealed that wider part of low hydrologically stable wetlandWetland falls under critical and stress WSSWetland Security State (WSS) exhibiting the impact of squeezing lateral flood extent.