Pub. L. 93-251, tit. I, sec. 84

Sec. 84. (a) The project for flood protection on Fourmile Run, city of Alexandria and Arlington County, Virginia, approved by resolutions of the Committees on Public Works of the United States Senate and House of Representatives; dated June 25, 1970, and July 14, 1970, respectively, in accordance with the provisions of section 201 of the Flood Control Act of 1965 (Public Law 84–298), is hereby modified to incorporate the following: (1) A channel capacity sufficient to accommodate flood flows of twenty-seven thousand cubic feet per second; (2) An increase in channel bottom widths along Fourmile Run from one hundred seventy-five to two hundred feet from Mount Vernon Avenue to Long Branch and from one hundred fifty to one hundred seventy-five feet above Long Branch, and, along Long Branch, from forty to sixty feet. (3) The deletion of the pumping stations, ponding areas, and levees, except for a short levee on Long Branch, and the substitution therefor of bank retention structures, including walls where required due to space limitations, and flood proofing by non-Federal interests of existing and future structures as necessary to provide protection against a one hundred-year flood; (4) The addition of recreation as a project feature, including pedestrian and bicycle trails, active and passive recreation areas, picnic areas, and protection of existing marshland area. 88 Stat. 36 (b) Prior to initiation of construction of this project, appropriate non-federal interests shall agree to— (1) provide without cost to the United States all lands, easement, and rights-of-way necessary for construction of the project; (2) accomplish without cost to the United States all relocations and alterations to existing improvements, other than railroads and the George Washington Memorial Parkway Bridge, which may be required by the construction works, including the reconstruction of the existing United States Route 1 highway bridge with its approach ramps; (3) hold and save the United States free from damages due to the construction works; (4) maintain and operate all the works after completion in accordance with regulations prescribed by the Secretary of the Army; (5) prevent encroachment on the project flood channels that would decrease the effectiveness of the flood control improvement; (6) provide at their own expense flood proofing of existing and future building and other measures as necessary to provide flood protection against a one hundred-year flood; (7) develop a land management planning process acceptable to the Secretary of the Army for the entire watershed, including Arlington and Fairfax Counties and the cities of Alexandria and Falls Church, to insure that future development in the basin will not result in increased runoff which would impair the effectiveness of the flood control improvement; (8) develop a land use management planning process satisfactory to the Secretary of the Army for the area protected by the project and other areas within the jurisdiction of the non-Federal interest or interests furnishing the cooperation for the project, which will insure, among other things, that future development will not be permitted in flood prone areas unless suitable structural or non-structural flood control measures are first undertaken by non-Federal public or private interests at no expense to the Federal Government; (9) contribute in cash toward construction of the project a sum estimated at $2,439.000, as follows: (A) city of Alexandria—one-half of the cost of construction of the channels and floodwalls between Commonwealth Avenue and Interstate 95, in the city of Alexandria, or $1,500,000, whichever is greater, (B) Arlington Comity—$500,000, (C) Richmond, Fredericksburg, and Potomac Railroad Company—$439,000; (10) pay 50 per centum of the separable costs of the project allocated to recreation, consistent with the Federal Water Project Recreation Act (Public Law 89–72). (c) There is authorized to be appropriated to the Secretary of the Army for construction of the Fourmile Run project not to exceed $29,981,000, plus or minus such amounts, if any, as may be justified by reason of ordinary fluctuation in the cost of construction as indicated by engineering cost indexes applicable to the type of construction involved.