A A A 2. INCREASING THE WATER SUPPLY OF WASHINGTON, DISTRICT OF COLUMBIA. This work was commenced under an appropriation made by act of Congress approved July 15, 1882. The plan consisted in raising the dam in the Maryland channel at the Great Falls of the Potomac to an elevation of 148 feet above mean tide at the Washington Navy-yard and its extension at that height across Conns Island and the Virginia channel of the river; extending the Washington Aqueduct from the distributing reservoir above Georgetown to the site selected for the new reservoir near Howard University by a tunnel 20,696.3 feet long; constructing at the tunnel outlet a new reservoir of about 300,000,000 gallons capacity, and connecting this reservoir by a new line of large mains with the existing system of water mains in the city of Washington. So much of the plan as related to raising and extending the dam at Great Falls was completed during the fiscal year 1887. No operations under the project were carried on during the past fiscal year. A watchman has been employed during the year at the new reservoir. His duties have included guarding the stone at the mouth of all shafts except the one at Foundry Branch, which is under the care of the watchman at the distributing reservoir. The following is a list of the appropriations for this work, with the date of act for the same: July 15, 1882.. March 3, 1885. March 26, 1886. Total.... $1,485, 279.30 87,500.00 87,500.00 5,000.00 555, 000.00 355,000.00 2,575, 279.30 The act of Congress approved March 2, 1895, making appropriations for the expenses of the government of the District of Columbia for the fiscal year ending June 30, 1896, and for other purposes, contained the following: For raising the height of the dam at Great Falls, together with the cost of such other work as may be found necessary in connection therewith, including the cost of strengthening the conduit, and for damages on account of flooding of land, and other damages, one hundred and twenty-five thousand dollars, for which amount and purposes the available balance of the appropriation for increasing the water supply of the city of Washington shall be applicable, subject to all the provisions and restrictions of the act to increase the water supply of the city of Washington, and for other purposes, approved July fifteenth, eighteen hundred and eighty-two, and of the act approved July fifth, eighteen hundred and eighty-four, making appropriations for the expenses of the government of the District of Columbia as to apportionment and settlement between the United States and the District of Columbia, and the refunding thereof. * RAISING THE HEIGHT OF THE DAM AT GREAT FALLS. This dam extended from the Virginia to the Maryland shore, crossing Conns Island. Its total length was 2,877 feet. The width of its crest in the Maryland channel was 7 feet 9 inches, and across Conns Island and in the Virginia channel 8 feet 3 inches. The reference of the crest was 148 feet above datum. (For details, see Sheet A.) During periods of extreme low water in the Potomac River the reference of the surface of the water at the mouth of the conduit feeder |