[Detail of assistants; vessels; instruments.] It shall be the duty of the Mississippi River Commission to direct and complete such surveys of the Mississippi River, between the Head of the Passes near its mouth to its headwaters as may have been in progress June 28, 1879, and to make such additional surveys, examinations, and investigations, topographical, hydrographical, and hydrometrical, of said river and its tributaries, as may be deemed necessary by said commission to carry out the objects of sections 641 to 644, 646, and 647 of this title. And to enable said commission to complete such surveys, examinations, and investigations, the Secretary of the Army shall, when requested by said commission, detail from the Engineer Corps of the Army such officers and men as may be necessary, and shall place in the charge and for the use of said commission such vessel or vessels and such machinery and instruments as may be under his control and may be deemed necessary. And the Secretary of Commerce shall, when requested by said commission in like manner detail from the National Ocean Survey such officers and men as may be necessary, and shall place in the charge and for the use of said commission such vessel or vessels and such machinery and instruments as may be under his control and may be deemed necessary. And the said commission may, with the approval of the Secretary of the Army, employ such additional force and assistants, and provide, by purchase or otherwise, such vessels or boats and such instruments and means as may be deemed necessary.

[Plans; report.] It shall be the duty of said commission to take into consideration and mature such plan or plans and estimates as will correct, permanently locate, and deepen the channel and protect the banks of the Mississippi River; improve and give safety and ease to the navigation thereof; prevent destructive floods; promote and facilitate commerce, trade, and the postal service; and when so prepared and matured, to submit to the Secretary of the Army a full and detailed report of their proceedings and actions, and of such plans, with estimates of the cost thereof, for the purposes aforesaid, to be by him transmitted to Congress: Provided, That the commission shall report in full upon the practicability, feasibility, and probable cost of the various plans known as the jetty system, the levee system, and the outlet system, as well as upon such others as they deem necessary.

[Plans for immediate works.] The said commission may, prior to the completion of all the surveys and examinations contemplated by sections 641 to 644, 646, and 647 of this title, prepare and submit to the Secretary of the Army, plans, specifications, and estimates of costs for such immediate works as, in the judgment of said commission, may constitute a part of the general system of works herein contemplated, to be by him transmitted to Congress.