This presentation showcases a hydrodynamic assessment of natural and nature-based features (NNBFs) for the Pascagoula River, the Escatawpa River and Grand Bay, located along the Mississippi coast of the northern Gulf of Mexico. Two separate NNBF projects are being considered to: (1) restore the historical footprint (ca. 1848) of Grand Batture Island for coastal protection purposes; and (2) reconnect the hydraulics between the Escatawpa River and Grand Bay for ecosystem services purposes. The intended coastal protection benefits of the first project include buffering agency to wave attack and attenuation of storm surge with the restored island. The intended ecosystem services benefits of the second project include replenishment of sediments to the salt marsh via increased hydroperiod (duration of tidal inundation) and availability for sediment accumulation. Astronomic tide and storm surge simulations are performed with the advanced circulation (ADCIRC) plus simulating waves nearshore (+SWAN) model to evaluate the hydrodynamic impact of the NNBF projects (Image). The simulated hydrodynamics are assessed firstly in terms of storm surge and waves for the open coast with and without the restoration of Grand Batture Island (Passeri et al., 2015), and secondly for tidal datums and inundation extent for the salt marsh with and without the hydraulic reconnection of the Escatawpa River with Grand Bay (Alizad et al., 2018). A key outcome from the analysis is the interconnectedness of the hydrodynamics within the system, where the implementation of the NNBFs results in local and non-local impacts. The numerical modeling approach with high-resolution feature definition at a system-wide scale affords such methodical evaluation of NNBFs for ecosystem restoration.