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.-- -C-1 (.. IV. ~ 20 METROPOLlTA]'.; WATER DISTRICT Patrol roads were graded and repaired as required to maintain them in serviceable condition. At Copper Basin reservoir the access road was extended abo,'e the gatehouse at the reservoir outlet to the south end of the reservoir and continued on to intersect the Barometer Wash road. A section of the transmission line patrol road between Iron Mountain and Danby Dry Lake was surfaced with select borrow material. Diagonal drainage channels were cleaned of growths. graded. widened and repaired where required. Leakage from the main aqueduct siphons was the most serious since completioh of the aqueduct. due to the necessity for the first time of continuous operation during the winter months. A low water temperature of 380F_ was measured in January ]948. The cold water caused excessive contraction of the concrete. thus opening cracks in the shell. Repair work was started during October and November 1947 when no water was flowing. in order to close cracks which had opened previously. In the siphons at mile ]8.24 and mile ]9_5], 46 cracks were repaired_ The large cracks were chipped out and calked with asbestos rope, oakum, lead. and plastic roof resurfaceI'. The small cracks. were buffed with a power brush and coated with liquid and plastic compound. After the water started to flow in December ]9.17, leakage at the connection of Eagle Mountain surge chamber to Eagle Mountain siphon measured in excess of ]00 gallons per minute. Repairs to this joint effectively stopped the leakage_ Low water temperatures caused leaks in Freda siphon flowing up to an estimated maximum of 330 gallons per minute_ The dumping of 75 sacks of sawdust into the intake end of the siphon was apparently effective in reducing leakage_ Leakage from other siphons also increased during periods of low water tempera- ture_ During the first half of January ]948 the Lakeview siphon was dewatered and repairs were made to 96 cracks. -Of these. 3] were repaired by enlarging the cracks to a width of % inch and depth of 2I/~ inches and then calking these openings with plastic roof resurfacer. oakum, and asbestos rope. The remaining cracks were cleaned, dried, and coated with a %.-inch layer of plastic roof resurfacer and finally painted with liquid roof resurfacer. No leakage was apparent after water was turned back into the line. By April ]948 the increased temperature of the flowing water had reduced all leakage to negligible quantities_ Repair work was con- tinued. however. during May and June 1948 to prevent future leakage at low temperatures_ One crack at Freda siphon and live at Pinto siphon were repaired from the outside by chipping, calking _J