It is unlawful to throw, discharge, or deposit any refuse matter, other than that flowing from streets and sewers and passing into a liquid state, into U.S. navigable waters or tributaries of navigable waters. [33 U.S.C. §407]

This prohibition does not extend to operations for the improvement of navigation and the construction of public works. [33 U.S.C. §407]

When anchorage and navigation will not be injured, the Secretary of the Army may permit the deposit of material into navigable waters. [33 U.S.C. §407] [Note: Section 402 of the Federal Water Pollution Control Act (FWPCA) provides that after October 18, 1972, no permits shall be issued under §13 of the Rivers and Harbors Appropriations Act of 1899; any such permits are to be issued under FWPCA §402. However, permits issued under the 1899 Act continue in effect unless revoked, modified, or suspended.]