PART 120—DEFINITION OF WATERS OF THE UNITED STATES Authority: 33 U.S.C. 1251 et seq. Source: 85 FR 22340, Apr. 21, 2020, unless otherwise noted. § 120.1 Purpose and scope. This part contains the definition of “waters of the United States” for purposes of the Clean Water Act, 33 U.S.C. 1251 et seq. [88 FR 3143, Jan. 18, 2023] § 120.2 Definitions. For the purpose of this regulation these terms are defined as follows: (a) Waters of the United States (1) Waters which are: (i) Currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide; (ii) The territorial seas; or (iii) Interstate waters; (2) Impoundments of waters otherwise defined as waters of the United States under this definition, other than impoundments of waters identified under paragraph (a)(5) of this section; (3) Tributaries of waters identified in paragraph (a)(1) or (2) of this section that are relatively permanent, standing or continuously flowing bodies of water; (4) Wetlands adjacent to the following waters: (i) Waters identified in paragraph (a)(1) of this section; or (ii) Relatively permanent, standing or continuously flowing bodies of water identified in paragraph (a)(2) or (a)(3) of this section and with a continuous surface connection to those waters; (5) Intrastate lakes and ponds not identified in paragraphs (a)(1) through (4) of this section that are relatively permanent, standing or continuously flowing bodies of water with a continuous surface connection to the waters identified in paragraph (a)(1) or (a)(3) of this section. (b) The following are not “waters of the United States” even where they otherwise meet the terms of paragraphs (a)(2) through (5) of this section: (1) Waste treatment systems, including treatment ponds or lagoons, designed to meet the requirements of the Clean Water Act; (2) Prior converted cropland designated by the Secretary of Agriculture. The exclusion would cease upon a change of use, which means that the area is no longer available for the production of agricultural commodities. Notwithstanding the determination of an area's status as prior converted cropland by any other Federal agency, for the purposes of the Clean Water Act, the final authority regarding Clean Water Act jurisdiction remains with EPA; (3) Ditches (including roadside ditches) excavated wholly in and draining only dry land and that do not carry a relatively permanent flow of water; (4) Artificially irrigated areas that would revert to dry land if the irrigation ceased; (5) Artificial lakes or ponds created by excavating or diking dry land to collect and retain water and which are used exclusively for such purposes as stock watering, irrigation, settling basins, or rice growing; (6) Artificial reflecting or swimming pools or other small ornamental bodies of water created by excavating or diking dry land to retain water for primarily aesthetic reasons; (7) Waterfilled depressions created in dry land incidental to construction activity and pits excavated in dry land for the purpose of obtaining fill, sand, or gravel unless and until the construction or excavation operation is abandoned and the resulting body of water meets the definition of waters of the United States; and (8) Swales and erosional features ( e.g., (c) In this section, the following definitions apply: (1) Wetlands (2) Adjacent (3) High tide line (4) Ordinary high water mark (5) Tidal waters [88 FR 3143, Jan. 18, 2023, as amended at 88 FR 61969, Sept. 8, 2023]