Definitions for "nonfunctional"
Riparian-wetland areas are considered to be in nonfunctioning condition when they don't provide adequate vegetation, landform, or large woody debris to dissipate stream energy associated with high flows and thus are not reducing erosion, improving water quality, or other normal characteristics of riparian areas. The absence of certain physical attributes such as a flood plain where one should be are indicators of nonfunctioning conditions.
Not having or performing a function.
Not performing or able to perform its regular function; as, the yard was littered with nonfunctional vehicles waiting to be repaired.
not performing or able to perform its regular function; "a malfunctioning valve"