Portland Increases Its Water Supply

Portland Increases Its Water Supply

Portland, Ore., recently finished a conduit from Bull Run as a supplement to the city’s water supply. The following is an article of the work performed under the directions of D. D. Clarke, M. A. M. Soc. C. E., superintendent of the system:

“The city of Portland, Ore., secures its watersupply from Bull Run River, which has its source in the Cascade Mountains, about fifteen miles northwesterly from Mt. Hood. The intake is at a point 24 miles from the city limits at an elevation of 720 feet above city datum. The original conduit was completed in 1894, and consists of 10 miles of 42-in., 8 miles of 35-in. and 6 miles of 33-in. riveted steel pipe. Its capacity is 22,500,000 gals, in 24 hours. The new conduit has a capacity double that of the original conduit, and consists of ten miles of 52-in. and fourteen miles of 44-in. lock-bar pipe. The 44-in. portion is constructed of 1/4-in. plates; the 52-in. line vary from 3/4-in. to 7-16-in. plates—the latter covering a length of but a few hundred feet at the crossing of the Sandy Canyon. The new conduit is located practically parallel with the old conduit and but a few feet distant therefrom. The three steel truss bridges (100-ft., 200-ft. and 300-ft. spans) constructed for the original conduit, were also used for the crossing of the new conduit over Bull Run and Sandy rivers. The contract for the new conduit was awarded to the Schaw-Batcher Co. Pipe Works, of Sacramento, Cal., in March, 1910, for the sum of $1,259,782. The pipe was manufactured by the East Jersey Pipe Co. at Paterson, N. J., and shipped by cars to Gresham, Ore., on the line of the proposed work. From this point the pipe was hauled with auto trucks and wagons to the line of the trench. The work of pipe laying was actually commenced Aug. 8, 1910, and the line was completed and the first water reached the city reservoirs at Mt. Tabor on Sept. 6, 1911. At the headworks a temporary connection has been made with the intake constructed for the original line, the inlet being 42 ins. in diameter, or 10 ins. less than the diameter of the new pipe. The capacity of the conduit under these conditions is 44,250,000 gals, per day. This amount will be appreciably increased upon the completion of the new and larger intake basin which it is proposed to construct at some future time at an elevation 30 ft. above the present works. The growth of the city has been exceptionally rapid during recent years, and the completion of the new conduit now insures a continuance of the same bountiful supply of Bull Run water which for years has been one of Portland’s most valued assets.”

No posts to display