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Great Fires: 1906 Great Earthquake & Fire

Spring to Water Supply is Reported to Have Always Been Insufficient
Experts Say That at its Best it Was Not Equal to the Requirments Existing
Before The Great Fire That Devastated The City
Men Prominent in the Engineering World Declare it Imparative
That The Municipality Own and Operate its Own System

 

1906 May 29
The conclusion has been reached by the sub-committee on water supply and fire protection, which reported yesterday to the reconstruction committee of forty, that the system of the Spring Valley Water Company was not only inadequate to meet the extraordinary demands upon it during the conflagration, but was inadequate for less severe requirements than were then considered efficient. It is the further opinion of this committee that the is in a much less efficient state now than before the fire, and it asserts that San Francisco can only be deemed safe from another conflagration, after it has established its own water system or some means can be devised to put an end to the everlasting controversy between the people and Spring Valley, a controversy that has resulted so disastrously to the city.

The committee that made this report is composed of men distinguished in the engineering world and is nonpartisan. It is a report based upon unbiased judgment and one that will be read not alone with interest, but with certain profit, by those now struggling to regenerate the destroyed metropolis.

The report was read by the chairman of the sub-committee, C. H. MeKinstry, major, Corps of Engineers, U. S. A., and member of the American Society of. Civil Engineers, and in addition to himself is signed by J. Dalzell Brown, vice-president and manager of the California Safety Deposit and Trust Company; Thomas P. Woodward, City Engineer; V. G. Bogue, member of the American Society of Civil Engineers; Charles D. Marx, member of the American Society of Civil Engineers; A. M. Hunt, member of the American Society of Civil Engineers, and, Edwin Duryea Jr., member of the American Society of Civil Engineers. The report follows;

The work assigned to this sub-committee was two fold in the matter of the present water supply and fire protection system we were asked to make recommendations suggested by the recent catastrophe, and in the matter of future supply we were asked to report which of all available sources and systems is in our opinion the most feasible and advisable. As to the latter, we desire to express our unwillingness to handle, this subject otherwise than in the manner in which an engineering project of this magnitude should be handled, viz. by making such an investigation as will enable at least a comparative estimate to be made of the merits and costs of the various available systems. This would involve months of field and office work done under the direction of able hydraulic engineers, assisted by competent legal advice in matters relating to water rights, titles, etc. It must be remembered that the tenders which the Supervisors have recently received are in most cases totally deficient in the kind of information on which a selection should, be based and that the various elements affecting the cost and desirability of each of perhaps a dozen projects will have to be worked out in detail. The general committee could have this investigation made if sufficient time and money were available. We advise, however, that the matter be dealt with through a commission of engineers, as has been done by Boston, New York and other large cities throughout the world that have solved the water supply problem satisfactorily.

PRESENT SYSTEM.
We think It due to the general committee to explain why in our reports and recommendations as to the existing, system of water supply and fire protection we have not gone more into detail why, for; example, we have not specified the number, capacity, and exact location of the city distributing reservoirs which we would advise, nor presented a map showing the sizes and locations of the distributing pipes with the gates, hydrants, etc., which we think necessary, for adequate fire protection. This again is a problem the details of which can be worked out only by long and painstaking study. We have tried to avoid suggesting anything that would hamper the engineers to whom this work should be entrusted and have aimed to present nothing more than the general principles on which any satisfactory plan must be founded.

This report Is based upon a personal inspection of the existing water system on statements made to us by competent observers, on interviews with various persons, including officials of the Spring Valley Water Company, and on the report of the National Board of Fire Underwriters on the water supply and fire-fighting facilities of San Francisco. The underwriters’ report, two copies of which are herewith, is dated October 1905, and is the result of careful examination and study on the part of competent engineers. Under the heads of "city in general,” fire fighting facilities and structural conditions and hazards it discusses the whole subject of fire risk in San Francisco. Under fire-fighting facilities it deals with the water supply and the organization, equipment and operations of the fire department, the fire alarm system and the various fire department auxiliaries. It describes the water system in detail and is accompanied by maps showing the locations of the Spring Valley reservoirs and conduits and the layout of the distributing system, and specifies the deficiencies in the various parts of the system which should be supplied to furnish adequate fire protection.

In view of the full account of the Spring Valley system contained in the underwriters' report an outline description I will suffice for our purposes wherein. The sources of the present systems are certain drainage areas on this peninsula and in Alameda County. The water obtained from the peninsular sources is stored in three reservoirs in San Mateo County namely, Pilarcitos, San Andreas and Crystal Springs. The water from Alameda County is obtained from sub-surface collecting works. The water from the storage reservoirs and from Alameda County was conducted into Lake Honda College Hill and University Mound distributing reservoirs by three conduits. The Pilarcitos conduit, which delivered water into Lake Honda by gravity, was wrecked by the earthquake and Pilarcitos water is now brought to the city through the San Andreas conduit and raised into Lake Honda by the Lake Merced pumps. In addition to the reservoirs mentioned there are three smaller ones, Francisco street Lombard street and Potrero reservoirs, and three tanks namely, Clay streets, Pacific Heights and Clarendon Heights tanks. These tanks are supplied from pumps.

The distributing mains leading from the city reservoirs and tanks to the various sections of the city are in general of ample size, but many laterals and cross-connecting pipes are too small to furnish adequate fire protection. We make this statement as, to the insufficient size of laterals and cross-connections on the authority of the underwriters report, having no direct means of informing ourselves on this point.

DEMAND WILL EXCEED SUPPLY.
The demand for water at the time when the "earthquake fire" occurred had reached a point where it was practicably equal to the developed supply. This fact was recognized by the Spring Valley Water Company, which was on the point of closing a contract for the construction of the Calaveras dam to form a large storage reservoir on Alameda Creek,

The present consumption is less than that immediately prior to the fire, and the delivery capacity of the system is likewise somewhat reduced by the destruction of the Pilarcitos conduit. Consumption, however, will rapidly increase and in a short time the demand will exceed the immediately available supply. The fire therefore has not done away with the necessity for taking immediate steps toward securing an increased 'supply.

The Pilarcitos and the main Crystal Springs dams were not injured. The geological fault line which traverses the Coast Range from Salinas to Mendocino County extends across, the easterly abutment, of the San Andreas dam. At the time of our Inspection the water stood about twenty feet below the crest of the dam and there Were no evidences of leakage. However, without raising the water level or excavating on the fault line it is impossible to determine whether or not the upper part of the dam is injured. Should injury be discovered it can easily be remedied. Mr. Schussler, chief engineer of the water company, informed the committee that he intends to excavate and make an examination. The Pilarcitos conduit which a for a considerable portion of its length is frequently, crossed by the fault-line, was over such Portion broken, telescoped, collapsed, pulled apart and damaged beyond the possibility of economical repair. We are informed that the water company intends to abandon this line for service course, which is advisable on account of its nearness to the fault.

OUTLINE OF DAMAGE.
The most serious injury to the San Andreas conduit was where it crosses the head of the Baden marsh. At this point there was a slip joint provided with ties connecting lugs on either, side of the joint. Several of these lugs were torn out by the shock permitting the water to escape. These breaks were temporary by repaired by the company within sixty hours. Several stretches of the Crystal Springs conduit were injured. At the Baden marsh crossing the pipe was ruptured in many places, and long sections were thrown from the trestle. A great length of the trestle was broken down. Examination disclosed that some of the timbers were decayed. To what extent this affected the amount of damage done it is impossible to state

No injury was done to any of the pumping stations.

The Alameda supply works were not injured.

The Alameda conduit and submarine pipes crossing the bay suffered no injury except to attachments at the San Mateo end, and to a slip joint at the Alameda end.

The distributing reservoirs were not injured, except Lake Honda, the concrete lining of which was cracked. This break was due to the displacement of a retaining wall by a sliding-bank set in motion by the earthquake. The distributing mains were injured in many places. Those from College Hill and University Mound reservoirs were completely severed, and those from Lake Honda badly damaged. We believe from the best evidence obtainable that all serious breaks occurred in made ground. These breaks rapidly wasted the water stored in the city reservoirs and cut off entirely the direct supply to the districts where the main fires originated.

The presence of many broken service pipes leading to burned houses made it very difficult to rehabilitate the pipe system rafter the fire had ceased, and allowed much waste of water with resulting low pressures and delay in filling reservoirs.

The design of the various parts of the Spring Valley Water Company's system and the materials used are generally excellent. The dam and reservoir walls are good examples of their types. The Iron used in the out of town conduits is of the best quality of laminated charcoal iron so thoroughly protected by the asphaltum coating employed that event he oldest of the pipes showed very little evidence of corrosion. The trestles across the marshes are not equal in permanence to other portions of the system, and in general the timber work is old arid not In the best condition. The materials used in the distributing mains are of good quality and the breaks in the mains were due to a great and' unforeseeable settlement of the ground.

RECOMMENDATIONS MADE.
The sub committee continues with recommendations as follows:

First --The protection against fires afforded by the system of the Spring Valley Water Company was inadequate, even as it existed before the earthquake-fire and for the less severe requirements then considered sufficient system is in a less efficient state now than before the fire, and, as shown by the earthquake, the emergency requirements are much more severe than hitherto realized.

Second— ln order to secure the certainty of fire protection it is imperative that the city own or control its own water supply. Definite and stringent legal agreement would better the present conditions of dual control, but if the strained relations continue which have existed between the city and the Spring Valley Water Company for many years no effective relief can be obtained except by city ownership.

Third--The three conduits leading from the storage reservoirs were ruptured by the shock. The destruction of the Pilarcitos conduits was due to Its nearness to the fault line and shows that future conduits should be placed as far away from faults as possible. The most serious injury to the Crystal Springs and San Andreas conduits occurred at marsh crossings. The lessons of the earthquake that marsh crossings should be avoided when possible. When soft ground must be crossed permanent material and substantial construction should be used. If timber is used it should protected from

Fourth --The failure to control was not due to the breaking of out-of-town conduits, but primarily to the fact that the eighty million gallons of water stored in the distributing reservoirs with in the city, a quantity sufficient to check even such a conflagration was rendered unavailable by reason of breaks in important distributing mains. The failures in the pipes of the distributing system occurred only In firm or soft ground and were not due in any case to the use of poor material. To meet earthquake conditions, the main arteries of the distributing system should be so laid as to avoid as far as possible all places where slips and ground movements resulted from the earthquake should have frequent cross connections and should be furnished, with a great number of gates and large hydrants properly disposed. All service pipes should be fitted with some device, such as a balanced valve, which will close automatically should the service pipe be broken.

We recommend that park locations shall not stand In the way of laying supply mains on lines which will give the best service. This is forced on our attention b the devious line of the main supply pipe to the Richmond District which should have crossed Golden Gate Park.

Where soft or made ground must be crossed special precautions should be taken to protect the pipe from injury by settlement of the ground for example, by the use of flexible joints slip joints, unyielding supports and sinuous alignment. It is entirely practicable, in our opinion, to provide a system of mains which as a system will not be seriously Injured by such an earthquake as occurred on April 18, 1906, or even one of greater severity. The character of the injury to the only one distributing reservoir damaged by the earthquake shows that a sufficient quantity of water for successfully fighting fires can be safely stored within the city limits. To add to the quantity of water stored within the city limits the number of the distributing reservoirs should be increased.

AUXI LIARY SALT WATER MAI NS.
Fifth— To afford additional fire protection within the congested value district we recommend that a separate system of mains be installed to be supplied with water pumped from the bay. We advise the installation of two pumping stations on solid ground, one at the base of Telegraph Hill and the other at the base of Rincon Hill, each to be capable of delivering at least 7500 gallons per minute with a hydrant pressure of 200 pounds per square inch. The foundations of the suction lines should receive special care in design and construction. The main artery connecting the two stations should be swung to the westward sufficiently to avoid insecure ground.

The system should be fitted at several points on the water front with connections into which fireboats or other floating pumps could discharge; At least one such boat should be provided simultaneously with the installation of the separate system recommended. It should be fitted with pumps of the same capacity as one of the land stations and with modern equipment for fighting fires along 'the dock front. We have communicated this recommendation to the sub-committee on special session of the Legislature to the end that the initiative may be taken to have such boat or boats provided by the proper State authorities. To avoid marine growths and corrosion the system should normally be kept filled with fresh water under pressure supplied from the regular service through connections provided with check valves to prevent salt water from backing into the fresh water system.

Sixth — We do not recommend the carrying out of the Twin Peaks reservoir project for the fire protection of the congested district, believing the above outlined system to be preferable. This reservoir scheme involves long mains, injury to which would render the system useless. The pressure which would result in the low district would also be greater than desirable.

Seventh — We indorse the action already taken by the city authorities for the acquisition of a municipal water supply and recommend that the construction of the special fire-protection system and the acquisition of a municipal system be carried out as quickly as possible.

Source: San Francisco Call, Volume 99, Number 181, 29 May 1906 — SPRING TO WATER SUPPLY IS REPORTED TO HAVE ALWAYS BEEN INSUFFICIENT. [CHAPTER]

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