THE OWENS RIVER AQUEDUCT.
If Los Angeles, Cal., utilises the water of the Owens river and its tributaries for its new supply, as seems more than probable, to do so will involve the building of an aqueduct of more than 200 miles, with a capacity of about 400 cu. ft. per second and a total fall of about 3,500 ft. The work will be full of difficulty, as the route lies over a rough and mountainous country. The water is of very good quality and can be used for domestic, laundry, boiler and irrigating purposes. The intake will be on Owen river, will be about 12 miles above the town of Independence, and there will be a large storage reservoir, where, also, the process of sedimentation will take place. There will be sixty miles of main canal to the Haiwee reservoir, and to that point the capacity will be 700 ft. per second, increasing to 900 ft., as the side streams are crossed, thereby gathering all the flood-discharge possible. from the Haiwee reservoir the water will be drawn at a uniform rate of 400 ft. per second, evaporation at the rate of 10 cu. ft. per second having been allowed for. The first twenty miles being through a clayey soil of close texture, no lining will be needed; for the forty miles of the canal there will be a concrete lining. At the head-works the hydraulic grade is 3,820 ft. above sea-level, and the high-water line of the reservoir will be 3.760 ft.—affording a 6o-sccondft. fall—an average of I ft. per mile to the reservoir, from which low-level to Little lake, 15.5 miles, the fall is 310 ft. This will be open conduit of small section lined with masonry and will follow smooth ground along a steep, natural gradient. From Little lake to Indiana wells— 24.5 miles—the line must be supported on the mountain side, 200 to 500 ft. above the valley at the base of the service. This will involve a successive series of tunnels, syphon pipes and bench conduits cut out of the solid rock and covered all the way with reinforced concrete. There will be eight syphons, with a total length of three miles and maximum head of 150 to 450 ft. The total length of the tunnels will be 5 miles. For the next twenty miles it is smooth, open valley land. The excavation will be easy, and there will be required only 3.750 ft. of steel flumes and syphon pipes for crossing dry washes coming out from the mountains. The second difficult section of the work begins with the summit of the ridge at Indiana wells valley, from Red Rock canon—21.5 miles. It calls for about 8 miles of tunnel, 3.5 miles of steel flumes and syphons and to miles of concrete-lined and covered conduit. The route lies through hardened clay, slate and sand, over a very broken surface. One canon will need a syphon pipe, with a maximum head of 850 ft. Smooth plains succeed, and the canal will cross the Southern Pacific railway, 2 miles north of Mojave, and extending round the whole head of the valley, west of Neenach, to a point nearly south of Fairmont 64.5 miles, there being only two exceptions a distance of 6 miles—.from a route of unbroken plain. The aggregate length of the aqueduct is about as follows: Unliocd canal, 22.20 miles; conduit lined with rubble masonry or concrete, 164.53 miles; tunnels in rock, 18.24 miles; tunnels in earth, to.n miles; syphons of steel pipe crossing canons, 8.99 miles; steel flumes crossing shallow anil narrow depressions, 180 miles; making a total of 22587 miles. The conduit has been estimated with a cover of reinforced concrete for a distance of 19.02 miles, or 11.6 per cent, of the entire lined section, the remainder to be left open for the first five years of operation. The Haiwee reservoir is the most important. It will be 7.4 miles in length. The south dam, the larger of the two, being 70 ft. in maximum height and 900 ft. top length. Substantial earth dams will e at each site. The capacity will lie 63.789 acre-feet, which can be increased to 82,350 by building the dams 10 ft. higher. The Long Valley reservoir, with a dam 140 ft. high, will have a capacity of 260.000 acrefeet or 85.000,000,000 gals. Its foundation will be a natural channel cut by the river through tufa rock. The total of line to be constructed will be 1,192.52s ft.—225.87 miles—exclusive of the Haiwee reservoir length. The cost is estimated at $18,221,300, plus extras that will bring it up to $24,485,600. It will take five years to build.
The water and light plant at Union City, Tenn., has now as its equipment the latest modern machinery, and for its size is one of the best in the State. The cost of the improvement was $3,000.