"Erosional features caused by proximate human activity" as used in RSA 482-A:3, IV(b) means scouring caused by stormwater runoff from areas developed so as to create an unnatural runoff area. The term includes gullies, rills, and other ephemeral features that do not meet the definition of a watercourse and that are characterized by flows that are infrequent and of short duration.
N.H. Admin. Code § Env-Wt 102.66