APPENDIX J. IMPROVEMENT OF POTOMAC RIVER AND ITS TRIBUTARIES, OF HARBOR AT BRETON BAY, MARYLAND, AND OF CERTAIN RIVERS ON WESTERN SHORE OF CHESAPEAKE BAY, MARYLAND AND VIRGINIA. REPORT OF MAJOR CHAS. E. L. B. DAVIS, CORPS OF ENGINEERS, OFFICER IN CHARGE, FOR THE FISCAL YEAR ENDING JUNE 30, 1892, WITH OTHER DOCUMENTS RELATING TO THE WORKS. 16. Establishment of harbor lines in Anacostia River (Eastern Branch of the Potomac), at Washington, District of Columbia. UNITED STATES ENGINEER OFFICE, GENERAL: I have the honor to forward herewith my annual report for the year ending June 30, 1892, on river and harbor works in my charge. Very respectfully, your obedient servant, Brig. Gen. THOMAS L. CASEY, Chief of Engineers, U. S. A. CHAS. E. L. B. DAVIS, Major, Corps of Engineers. J 1. IMPROVEMENT OF POTOMAC RIVER AT WASHINGTON, DISTRICT OF COLUMBIA. ORIGINAL CONDITION. Previous to this improvement the channel to Georgetown, D. C., was narrow and crooked, so that vessels drawing 16 feet of water often grounded above Long Bridge, and frequent dredging became necessary to maintain even this depth. On account of the smallness of the appropriations only narrow cuts could be dredged, entirely inadequate to the needs of commerce. The Washington Channel was also narrow and shoal. From Observatory Hill to a point abreast of the Arsenal large flats had formed, separated from the mainland below Long Bridge by the Washington Channel, with its sluggish currents, due to the ebb and flow of the tides. These flats were alternately covered and exposed to the sun's rays by the tide, whose average rise and fall at Washington is 3 feet, while the large sewer at the foot of Seventeenth street NW. discharged directly upon them. These conditions combined to generate an effluvium that became an intolerable nuisance, rendering certain portions of the city almost uninhabitable, and really endangering the health of the city. PLAN OF IMPROVEMENT. The proposed plan of improvement adopted by the act of Congress of August 2, 1882, has for its object to improve the navigation of the river by widening and deepening its channels; to reclaim or fill in the flats by depositing on them the material dredged from the channels; to purify the water in the Washington Channel, and to establish harbor lines beyond which no wharves or obstructions shall be built. To accomplish these purposes such depths of channels are to be provided as will accommodate the largest vessels that can reach Arsenal Point, with such depths at the wharves as will allow vessels to receive full cargoes without grounding at low water; the Flats above Long Bridge are to be filled in to a height of 3 feet above the flood line of 1877; below Long Bridge the middle line of the Flats is to be filled up to the same height, but the Flats are to slope each way to a height of 6 feet above low tide at the margin of the fill; to purify the water in the Washington Channel, cut off at its upper end from the Virginia or Main Channel, a tidal reservoir or basin is to be established above Long Bridge, to be filled with water from the Virginia Channel on the flood tide, and discharged into the Washington Channel on the ebb. The project also provides for the rebuilding of the Long Bridge at an early period during the progress of the improvements, with wide spans, upon piers offering the least possible obstruction to the flow of water, and the interception of all sewage now discharged into the Washington Channel and its conveyance to the James Creek sewer canal; but neither of these two works was included in the estimated cost of the improvement, which is $2,716,365. Appropriations have been made as follows: |