Before 1875 the supply of water was obtained from creeks on the eastern slope of the mountains lying east of Lake Tahoe, but in the year named, the water company pushed their main supply flumes through to Marlette Lake, which lies inside of the Tahoe basin. To do this it was necessary to run a tunnel 3,000 feet in length through the dividing ridge, or rim, of the Tahoe basin. The sheet of water known as Marlette Lake is almost entirely artificial, and owes its existence to a big dam—is in reality a large reservoir. The water covers an area of over 300 acres, and in the middle is about 40 feet deep. The reservoir holds 16,000,000,000 gallons of water. The second pipe was laid under the supervision of Capt. J. B. Overton, Superintendent of the works of the water company, who also extended the flumes, constructed the tunnel through the mountain ridge, and made all the other improvements. In 1887 a third iron pipe of twelve inches inside diameter was laid across the valley alongside the first two. It was also a welded pipe and delivers much more water than either of the others. The inlet pressure has been raised on all three pipes, and they now deliver a total flow of about 10,000,000 gallons in twenty-four hours. In 1887, also, a branch flume was run to the northward (Marlette Lake lying to the southward) a distance of nine miles, which taps a number of creeks tributary to Lake Tahoe on the east and northeast sides. In the same year a reservoir capable of holding 20,000,000 gallons was constructed on Hobart Creek, on the east side of the dividing ridge. In and near the city are reservoirs holding from 3,000,000 to 10,000,000 gallons, and a number of tanks along the side of Mount Davidson of from 60,000 to 80,000 gallons, capacity. The water is brought a distance of from twenty-five to thirty-seven miles, and the supply (aided by the several storage reservoirs) is ample for all present uses. The total cost of the works of the company has been about $2,500,000. Each of the three pipes has its separate inlet and outlet, from two flumes and into two flumes. Between the outlet and the city the water passes through a large storage reservoir. The Sutro Tunnel.