All moneys or profits as determined by the Secretary heretofore or hereafter derived from the sale or rental of surplus water under the Warren Act of February 21, 1911 (
36 Stat. 925) [
43 U.S.C.
523 to
525], or from the connection of a new project with an existing project shall be credited to the project or division of the project to which the construction cost has been charged.