Floodplain health is recognized as an important component in stream restoration. Functioning floodplains can provide not only physical hydraulic benefits, but also water quality and ecological benefits through their biogeochemistry. Many stream valleys in the East Coast contain major deposits of upland soils that flooded into the valleys during the era of forest clearing following European colonization (“legacy sediment”), burying wetland soils which had established over thousands of years. While these relict hydric still exist, little is known about the ecological function and water quality services (e.g., denitrification) they may provide once reconnected to hydrology and the root zones of riparian vegetation. Denitrifying functions are reflected in Protocol 2 of the Maryland Expert Panel Consensus Recommendations on Stream Restoration Crediting.