natural and beneficial floodplain functions

(A) the functions associated with the natural or relatively undisturbed floodplain that (i) moderate flooding, retain flood waters, reduce erosion and sedimentation, and mitigate the effect of waves and storm surge from storms, and (ii) reduce flood related damage; and

(B) ancillary beneficial functions, including maintenance of water quality and recharge of ground water, that reduce flood related damage;