Additional Water Supply for San Francisco.
For the better defence of San Francisco against fire the engineers intend to protect an area of 82-10 sq. miles—nearly double the burned area—with a high-pressure system, the distributionpipes of which are installed on the same general lines as followed in New York city. This system will have as supplies two storage-reservoirs, with a combined capacity of 10,000,000 gal. located on Twin Peaks, and distributing reservoirs so arranged as to furnish water to two zones at suitable pressures for direct hose use. Water to supply the reservoirs will be obtained from the domestic-service mains through two force-pumps, each having a capacity of 1,500,000 gal. a day. It will be possible to pump directly into the ma ns or to increase the pressure by throwing the higher reservoirs into service. In addition, salt-water stations and fireboats are designed to pump against either the lower ordinary pressures or the highest emergency pressures. There will be two salt-water pumping stations on the waterfront and two large fireboats, each capable of discharging 8,000 gal. a minute, which can be used independently or be connected with a pipe-system. The total estimated cost of the system is $5,200,000. The committee of twenty of the National Board of Fire Underwriters requires that the system shall be designed so that 15,000 gal. of water per minute may be concentrated in any area in the congested-value district of too,000 sq. ft. While on this subject, attention may be called to an erroneous impression in the mind of the public as to the difficulty of controling a general conflagration. The comparative ease with which the conflagration was checked along Van Ness avenue and in the Mission was misleading. The fire originated in the eastern part of the city and spread in the direction contrary to that in which the prevailing wind was blowing, so that it was retarded rather than assisted by this wind. As regards the present water system, the hydrants are “insufficient”; the mains “do not meet the requirements of good service; and there are available “no reliable data concerning size, age, construction or condition.” The 30-in. main connecting lake Merced and the Ocean View pumps with lake Honda has outlived its period of reliability and may fail at any time. Materials for a new 30-in. main are on the ground, installation being prevented by an injunction granted stockholders of the company restraining directors from making expenditures of funds on new work. During July and August of 1907 the amount of water in lake Honda, dropped to 7,000,000 gal., at which level it remained for several days. rite pumps were taxed to the utmost, but were unable to increase the available water until the demand decreased, due to the moderation of the weather. Lake Honda’s capacity is 12,000,000 gal.; maximum capacity of Ocean View, and lake Merced pumps, 10,000,000 gal.; average daily consumption, 8,000,000 gal. The Pilarcitos line has been abandoned.