Sections 13370 through 13389 of the Water Code were enacted to implement provisions of the Federal Water Pollution Control Act (33 U.S.C. 1251 et seq.; hereafter the federal Act). ( Wat. Code, 13370.) Water Code section 13376 requires anyone who discharges, or proposes to discharge, a pollutant, dredged material, or fill into the navigable waters of the United States must file an appropriate report, unless the discharges are not subject to the federal Act. In certain situations, violations of this requirement are subject to criminal penalties. ( People v. Buena Vista Mines, Inc. (1996) 48 Cal. App. 4th 1030, 1034-1036 56 Cal. Rptr. 2d 21; Wat. Code, 13387, subd. (a).) Generally, the federal Act regulates only discharges of pollutants from "point sources." (People v. Buena Vista Mines, Inc. (1998) 60 Cal. App. 4th 1198, 1202-1203 71 Cal. Rptr. 2d 101.) This term, like the terms, "navigable waters," "pollutants," and "discharge," has the same meaning under the federal Act and the Water Code. (Wat. Code, 13373.) The term "navigable water" encompasses any river or stream that is a tributary of tidal waters. (See People v. Appel (1996) 51 Cal. App. 4th 495, 504 59 Cal. Rptr. 2d 216.) Concrete, rebar, sand, and similar waste materials are pollutants. (U.S. v. West Indies Transport, Inc. (3d Cir. 1997) 127 F.3d 299, 307-308; see People v. Appel, supra, 51 Cal. App. 4th at p. 504; 33 U.S.C. 1362(6).) Under the federal Act, a "point source" is "any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged." (33 U.S.C. 1362(14).) This term has been broadly construed, even in actions involving criminal sanctions. (People v. Buena Vista Mines, Inc., supra, 60 Cal. App. 4th at p. 1203 holding pond containing contaminated water is a point source for purposes of criminal prosecution under Water Code; U.S. v. Oxford Royal Mushroom Products, Inc. (E.D.Pa. 1980) 487 F. Supp. 852, 854 irrigation system, coupled with broken berm, is a point source for purposes of criminal prosecution under federal Act.)