The original wasteway, constructed at the north end of the dam, has been practically abandoned, having been substituted by a tunnel of larger capacity. The original wasteway was excavated in the bed rock of the natural hillside, and although lined with masonry, is not in the best condition. The author considers its location an objectionable feature, as menacing the safety of the dam, and thinks it should be permanently closed. A wasteway tunnel, 1,487 ft. in length, was constructed in 1888, through a ridge extending north of the dam. This has a sectional area of about 10×10 ft., lined with brick masonry throughout, having a grade of 2½%. The criticism might be made of the tunnel that it is faulty in design at the entry or reservoir end, where the water must first fall over a high spillway wall, aerating the water before entering the tunnel proper. The water even then has not easy access to the tunnel, and no adequate arrangements have been made for ventilation, so as to insure the utilization of its maximum capacity. The maximum depth of water in the reservoir is about 85 ft., and the full capacity 689,000,000 cu. ft. of water. The catchment area is 43 square miles, and the surface of the reservoir when full 436 acres. The outlet pipes are placed in two tunnels at different elevations through the ridge north of the dam. There are no culverts or pipes extending through the body of the dam itself. Hydraulic-fill Dams. No discussion of earth dams would be complete without some reference being made to the novel type of construction developed in western America in recent years, by which railroad embankments and water-tight dams are built up by the sole agency of water. The water for this purpose is usually delivered under high pressure, as it is generally convenient to make it first perform the work of loosening the earth and rock in the borrow pit, as well as subsequently to transport them to the embankment, and there to sort and deposit them and finally part company with them after compacting them solidly in place, even more firmly than if compressed by heavy rollers. Sometimes, however, water is delivered to the borrow pit without pressure, in which event the materials must be loosened by the plow or by pick and shovel by the process called ground sluicing in placer mining parlance.