Board of Review to Evaluate Mulholland Dam (1930)
Concerned about the political fallout that might emerge from the State’s External Review Panel, in March 1930 the City of Los Angeles Board of Water & Power Commissioners appointed their own Board of Review for Mulholland Dam, which included Harvey Van Norman, Chief Engineer and general manager of the city’s Bureau of Waterworks and Supply, and Los Angeles consulting engineers Louis C. Hill of Quentin, Code & Hill and A. L. Sonderegger (water resources engineer). Their report was issued on March 27th and recommended that a massive earth and rock fill embankment be placed against the downstream face of Mulholland Dam, “because this would add to the stability of the structure and because of the psychological effect it would have, changing the apparent menace to a pleasing view carrying no suggestion of a dam. The panel added that the massive fill “would make it impossible for the dam to fail if subjected to an earthquake shock great enough to destroy Hollywood.” They also recommended “that Hollywood Reservoir be maintained at a level 31 feet below spillway crest in order to maintain the resultant thrust within the middle third of the structure.” As a result of this report, the dam’s spillway was lowered from elevation 746 ft to 715 feet in March 1932.
Board of Engineers to Evaluate Mulholland Dam (1931)
Unhappy with the findings of the previous boards, Los Angeles Mayor John C. Porter and City Councilman James M. Hyde (representing Hollywood) requested that the Board of Water & Power Commissioners appoint a second board to examine the possibility of abandoning Mulholland Dam and Hollywood Reservoirs, because of anxiety of the residents of Hollywood, living below it. On April 15, 1931 a new board of consulting engineers was appointed to examine the abandonment and how alternative water supplies might be employed to assuage its removal. This new board was comprised of Los Angeles consulting engineers B. F. Jakobsen and Charles T. Leeds, and USC Geology Professor Allen E. Sedgwick. The board issued a preliminary report in July 1931 the panel recommended removing the dam to ally public fears and apprehension. This board failed to agree in its final report and presented two separate opinions. Jakobsen and Sedgwick favored dismantling the structure because the resultant thrust was not within the middle third of the dam’s base and a fault in the foundation. In his minority report, Leeds disagreed and stated his belief that the dam was safe as it stood, without any retrofitting.
Geological Report of the Suitability of Foundations for Mulholland Dam (1931)
In response to the majority report cited above, The Los Angeles Board of Water & Power Commissioners retained Columbia University Geology Professor Charles P. Berkey to make an independent assessment of the foundation conditions of Mulholland Dam and issue a report concerning the suitability of said foundations to support the curved concrete gravity dam. At the time, Berkey was the most respected engineering geologist in America and was serving on the Colorado River Board appointed by Congress to review the technical aspects of the Hoover Dam. Berkey’s examination of the dam’s foundation exonerated the criticisms by Allen Sedgwick, and he pronounced the rock sufficiently sound to support a concrete gravity dam.
Board of Consultants-Proposed Alterations & Improvements for Enlargement of the Chatsworth Reservoir (1931)
Chatsworth Dam and reservoir was built by the City of Los Angeles for their Los Angeles [Owens River] Aqueduct in 1918, in the southwestern corner of the San Fernando Valley. It was built of hydraulic fill and tamped fill on the crest, and provided with a paved concrete face, with a design capacity of 10,000 acre-feet. The earthen embankments were constructed on a pervious foundation of unconsolidated late Quaternary age alluvium. On August 30, 1930 the M 5.2 Santa Monica Bay earthquake caused noticeable vertical cracking of the embankment crests, due to partial liquefaction and lurching, which increasing leakage.
As a consequence of these problems, a Board of Consultants appointed by the Los Angeles Department of Water & Power to review that agency’s design of proposed improvements to the reservoir, which were intended to enlarge its storage capacity. This board was comprised of: retired Stanford Professor Charles D. Marx, Los Angeles consulting engineer J. B. Lippincott, and Caltech Geology Professor John Buwalda. Although this board approved of the various measures proposed by LADWP to bolster the embankments and repair the observed cracks and differential settlement (this work was carried out in 1931-32, by regarding embankments and recompacting with sheepfoot rollers).
The reservoir was never capable of storing its design capacity because of excessive foundation seepage (the Chatsworth Park Reservoir, a 40 ft high embankment dam constructed nearby in 1900, never retained more than 10 feet of water). The dam was eventually taken out of service in August 1969 because of concerns for its seismic safety, given the pervious nature of its foundations.
Board of Consultants to Evaluate Earthquake Design of Pine Canyon [Morris] Dam (1932-33)
After discovery of the dormant fault at the base of the dam’s right abutment, a panel of experts was convened by the City of Pasadena to provide advice on how the dam’s design might be altered to make it safe, using conservative assumptions. This panel was comprised of Professor H. M. Westergaard of the University of Illinois, Professor Lydik Jakobsen of Stanford University, seismologist Harry O. Wood of the Carnegie Institute in Pasadena (absorbed into Caltech in 1934).
The exposed fault was found to dip into the base of the right abutment at an angle of about 60 degrees from horizontal, towards the northwest. The dam was provided with a specially-designed “slip joint,” which is three feet of open space extending up the entire height of the dam. This slip joint can accommodate up to 6.55 feet of dip slip, without impacting the resultant thrust in the dam.
Pine Canyon Dam was also instrumented with Carlson strain meters, identical to those used in Hoover Dam during the same interim (1931-35). Photo-elastic studies of the intensity and distribution of stresses in the dam were also carried out by J. H. A. Brahtz, under the supervision of Professor Theodore von Karman at Caltech. The dam’s chute spillway was also model tested at Caltech, leading the addition of the interior training walls, to promote laminar flow and reduce edge effects. The spillway capacity is 80,000 cfs.
Board of Consulting Engineers for the Bouquet Canyon Dams (1932-33)
This board was appointed by the Los Angeles Department of Water & Power to review the plans prepared by LADWP for the proposed Bouquet Canyon Dams, replacing the ill-fated St. Francis Dam, and intended to store a year’s supply of water from the Los Angeles Aqueduct, south of the San Andreas fault. The board was comprised of three prominent southern California engineers: Charles T. Leeds, Louis C. Hill, and J. B. Lippincott. DWP had previously solicited input from a number of other engineers and geologists, including: geologists Charles P. Berkey of Columbia University, Allen E. Sedgwick of USC, Robert T. Hill, retired from the USGS, F. Leslie Ransome of Caltech, and consulting mining engineer Rush T. Sill. Other engineers providing input included Thaddeus Merriman (retired Chief Engineer New York Board of Water Supply) and R. E. McDonnell, of the newly formed State Division of Safety of Dams.
External Review Panel to evaluate Bouquet Canyon Dam (1932)
This panel was convened in 1932 under the auspices of the State’s new Dam Safety Act of 1929 to evaluate the proposed Bouquet Canyon Dams in Bouquet Canyon (described above). This panel was appointed by the State Engineer, Edward J. Hyatt, and was chaired by retired Stanford University civil engineering chairman Charles D. Marx, San Francisco consulting engineer Walter L. Huber, and F. C. Herrmann, former Chief Engineer of the Spring Valley Water Co of San Francisco.
Coroner’s Jury in the Inquest of Victims of the Long Beach Earthquake (1933)
Inquest convened by Los Angeles County Coroner Frank A. Nance to investigate the structural failure of public buildings during the M 6.3 Long Beach earthquake of March 10, 1933, which killed 120 people, destroyed 70 schools and damaged 120 more. The jury was comprised of ‘construction experts,’ whose charge was to “go beyond the mere determination of the cause of the deaths in order to find the reasons for the loss of life and to develop the possibility of providing more earthquake-resistant construction, particularly for schools and public buildings.”
Architect John C. Austin, former President of the Los Angeles Chamber of Commerce, served as Chairman of the Jury. He was assisted by mining/petroleum engineer Sterling C. Lines, among others.
The jury convened for 8 days in early April 1933 and issued a verdict of just 3,500 words, which included: “that every masonry building of any height, and every wood-frame building more than two stories high, be designed by either a licensed architect or a registered structural engineer and that every skeleton frame building be designed structurally by a registered structural engineer or a certified architect who qualifies as a structural engineer.”
The Coroner’s Jury recommended that earthquake provisions of the new Uniform Building Code be immediately adopted in Los Angeles County. District Attorney Burton Fitts transmitted the findings of the Coroner’s Jury to the 1933 Los Angeles County Grand Jury, to seek their opinion as to what course of action should be undertaken. They recommended that the Uniform Building Code should immediately be adopted by the County. Local governments in Southern California soon followed. The cities of Long Beach, Los Angeles, Santa Monica, Beverly Hills, and Pasadena adopted similar building codes.
Joint Technical Committee on Earthquake Protection (1933)
The Joint Technical Committee on Earthquake Protection was organized following the March 1933 Long Beach Earthquake. It was the first earthquake with strong motion recorders in the near-field area, which measured horizontal accelerations between 0.1 and 0.3g, far higher than many expected. The committee ,members were drawn from the American Society of Civil Engineers, American Institute of Architects, Structural Engineers Association of Southern California, American Association of Petroleum Geologists, Seismological Society of America, Associated General Contractors, Los Angeles Engineering Council of Founder Societies, Board of Fire Underwriters of the Pacific, and the Los Angeles Board of Education, Chamber of Commerce, and other civic organizations.
The representatives included: Caltech President Robert A. Millikan as Chairman, Professor Romeo R. Martel of Caltech (Vice Chairman), architect John C. Austin, Sumner Hunt, David J. Witmer, civil engineer Raymond A. Hill, foundation engineer R.V. Labarre, structural engineer Oliver G. Bowen, structural engineer Blaine Noice, Caltech geology Professor John P. Buwalda, consulting geologist Harry R. Johnson, P.L. Connolly, Harold H. Crowell, L.E. Dixon, petroleum engineer Ralph J. Reed, J.E. Shield, Harry H. Baskerville, Zack J. Farmer, and William A. Simpson. Their report was titled: Long Beach Earthquake and Protection Against Future Earthquakes -- Summary of Report by Joint Technical Committee on Earthquake Protection, Dr. Robert A. Millikan, Chairman, dated June 7, 1933. This became the seminal document which influenced the Riley and Field Acts passed by the State legislature, shortly thereafter (see below).
Boards of Consulting Engineers to the Los Angeles County Flood Control District (1931-38)
In October 1930, the Los Angeles Flood Control District (LACFCD) began surveying a dam site two miles downstream of their ill-fated Forks Dam site, described above. In August 1931 E. Cortland Eaton, Chief Engineer of LACFCD recommended that the county board of supervisors that the County establish an engineering consulting board to supervise the final exploration and design work for the proposed rockfill dams in San Gabriel Canyon: San Gabriel Dam No. 1 and No. 2 on the West Fork (later named Cogswell Dam). This 1931 board consisted of: Louis C. Hill of Quentin, Code & Hill consulting engineers in Los Angeles, A.J. Wiley of Boise, Idaho, retired USGS geologist Robert T. Hill of Dallas, Texas, and Stanford geology Professor C.F. Tolman.
In June 1932 LACFCD received approval from the State Division of Dam Safety to build San Gabriel Dam No.1 as a 375-ft high rockfill dam. The county let the first contract in January 1933, after rejecting the first and second round of bids, which exceeded the estimated cost of $10 million. Construction began in the spring of 1933, but was shut down in mid-October 1934, when LACFCD sought to sort out the recommendations made by two different panels (described below).
By the fall of 1933 problems with perceived suitability of the excavated rock prompted Chief Engineer E. Cortland Eaton to name a special board of consultants to review the conditions at the dam and quarry sites in San Gabriel Canyon. This second board was amended to include the following individuals: George A. Elliott of the Spring Valley Water Co. in San Francisco, Louis C. Hill of Los Angeles, consulting mining engineer Rush T. Sill (BSGeE ’06 CSM) and Professor C. F. Tolman of Stanford University. This board issued reports on the San Gabriel Dam in July and September 1934 which called attention to the weathered condition of the rock being excavated for the dam in San Gabriel Canyon, and suggesting that it was unsuitable for the original design of the rockfill dam, which called for side slopes of 1.6:1 to as steep as 1.3:1.
In August 1934 E.C. Eaton resigned from his post as Chief Engineer of the Los Angeles County Flood Control District (LACFCD), and was replaced by Samuel M. Fisher. Prior to Fisher’s appointment another board of consulting engineers was appointed to advise the county on various aspects of San Gabriel Dam Numbers 1 and 2. This board was comprised of: Chairman Leroy F. Harza (BSME 1901 South Dakota State; BSCE ’06 Wisconsin) of the Harza Engineering Co. of Chicago, Ralph J. Reed, Chief Engineer of the Union Oil Co. of Los Angeles, and I. C. Steele of PG&E in San Francisco, a noted expert on rockfill dams.
This second board issued their own report concerning the San Gabriel Dams, dated October 8, 1934. This group recommended that San Gabriel Dam No. 1 be re-designed with flatter side-slopes, incorporating 1,500,000 yds3 of the less-suitable waste rock into the dam’s sloping shells, flattening the downstream slope from 1.3:1 to 2.5:1. In the end, approximately 10.8 million yds3 of rock were excavated for the project. The dam was completed in July 1937, the spillway in February 1938, and the outlet works in August 1939.
San Gabriel Dam No. 2 is a 242 ft high rockfill dam constructed by the district in 1932-34 along the West Fork of the San Gabriel River. Boulders weighing as much as 30 tons were incorporated into the five million yd3 fill. Much material was sluiced into the canyon during the early going (1932), without benefit of mechanical compaction. After severe winter rains in early 1934, the embankment settled as much as 12 feet, destroying the concrete slab lining the upstream face. The board recommended removal and replacement of the old facing, covering it with timber and sluicing of additional 60,000 yds3 against the downstream face. The structure was renamed Cogswell Dam in 1952.
During the tenure of C. H. Howell (BSCE ’05 Illinois) as Chief Engineer (Feb 1935-Oct 1938) the district employed F. E. Trask, former chief engineer for the California State Advisory Board of the Public Works Administration (who had also designed several dams in southern California), William P. Creager, consulting engineer from Buffalo, NY, and Chicago consulting engineer Leroy F. Harza, to advise the County on various aspects of dam design and construction. All of these men were well respected nationally, and Creager had written the textbook Engineering for Masonry Dams, published in 1917 and 1929.
First dynamic properties evaluation of a dam (1934)
In the wake of the Ms 6.25 March 1933 Long Beach Earthquake, the U.S. Coast Geodetic Survey allotted funds for the determination of dynamic properties of important structures. They hired a young structural engineer named John A. Blume, PE (AB ’33; MEng ’35; PhD ‘67 Stanford), who built a dynamic exciter and used it on Morris Dam to determine the fundamental periods of vibration and deflection characteristics. Blume determined that the fundamental period of vibration was 0.20 seconds and about 0.17 seconds for the second mode. He reported these findings in a articles titled ”A machine for setting structures and ground into forced vibration,” which appeared in the Bulletin of the Seismological Society of America in 1934 (v. 24:361-386).
Special Consulting Board for San Gabriel Dam No 1 (1934-35)
In November 1934 State Engineer Edward Hyatt used his powers granted under the Dam Safety Act of 1929 to appoint a special board of consultants to examine the design of the San Gabriel Dam No. 1 by the Los Angeles County Flood Control District, after considering concerns raised by the U.S. Forest Service and recommendations to the LACFCD by their own consulting boards. This board was comprised of: former Stanford Professor Charles D. Marx, SE consulting structural engineer of San Francisco, Walter L. Huber, PE consulting civil engineer of San Francisco, and F.C. Herrmann, former Chief Engineer of the Spring Valley Water Co of San Francisco. The board issued a report on May 13, 1935 disapproving the use of random rock fill for stability of the earth-rockfill dam, slated to be the highest of its type in the world. The project was shut down between Nov. 13, 1934 and July 26, 1935, to allow the state’s board to review the project and come to an agreement with the LACFCD on a revised design. Construction work resumed in August 1935, and the new design dropped the side slopes of the embankments to 3:1, while increasing the spillway capacity to >200,000 cfs. The panel believed that these adjustments would increase the dam’s cost to $11.57 million, but the final cost of the project was $17 million.
City of Los Angeles ad hoc Geologic Hazards Committee (1956-60)
Following a violent two-day storm that caused considerable property damage in January 1956, the city formed this committee in May 1956. That same month Los Angeles began requiring geologic reports prior to issuing grading permits and the City promptly formed an ad hoc Geologic Hazards Committee, comprised of geologists (Drs Richard Jahns and Robert Stone, and possibly, others) and soils engineers (Leroy Crandall, L.T. Evans, and possibly, others). This committee recommended that the City require more exhaustive engineering geologic assessments of hillside development. This was a problem, because the City did not have a geologist on staff to review such reports, nor was there any means by which to judge the qualifications of geologists submitting such reports. Between 1956-61 Los Angeles and several other cities began requiring geologic reports for development of hillside parcels, but geologist were not required to make observations during construction until several years later (described below).
Board of Engineering Consultants to California Department of Water Resources (1956-60)
Chair Walter L. Huber (1883-1960), consulting engineer in San Francisco, A. H. Ayers (former Bureau of Reclamation and Six Companies Office Engineer), Samuel B. Morris (1892-1962), Raymond A. Hill, (1892-1973), partner Leeds, Hill & Jewett, and Ralph A. Tudor (1902-62) of Tudor Engineering Co. of San Francisco. This was the panel of five engineers that oversaw development of the California Water Plan (summarized in DWR Bulletin 3 in 1957).
City of Los Angeles Engineering Geologist Qualifications Board (1958)
This board was established by the Los Angeles Dept. of Building & Safety on February 10, 1958 to provide a means of improving the quality of engineering geologic reports for hillside residential development. This panel was chaired by Professor Richard H. Jahns at Caltech. The board then prepared an article titled “Desired Content of Geological Reports,” which was edited by Jahns and widely distributed, beginning in May 1960 (Milburn, 1965; Jahns, 1969). In the early 1960s this board was comprised of soils engineers J. Robert Davis and LeRoy Crandall, and engineering geologists Beach Leighton and Dick Proctor.
Los Angeles County Engineering Geologist Qualifications Board (1960)
Early in 1960, it became apparent that standardization of the quality of engineering geologic reports submitted to the County of Los Angeles was necessary. The grading division recommended and the Board of Supervisors adopted Ordinance No. 7754 which established the Los Angeles County Engineering Geologist Qualifications Board to examine, test, and register consultants. This Board was formed to act in the absence of State regulation of this profession as a board of examination and certification of engineering geologists who wished to submit reports required by County ordinances. The Board consisted of five regular members, plus an ex-officio member. The regular members served without compensation and were frequently called upon to meet, more than once per month during the early 1960s, when qualifications were being examined at a rapid rate. The original members of this board were: County Geologist Dennis Evans, Paul Merifield, Perry Ehlig, and Richard J. Proctor. This Board was instrumental in the upgrading of the standards of engineering geologic reports in southern California.
Los Angeles Grading Advisory Board (1960 onward)
A Grading Advisory Board for LA Dept of Building & Safety was established around ~1960. Its members included soils engineers Leroy Crandall, Fred Converse, and L.T. Evans, USC Geology Professor Tom Clements and Caltech Geology Professor Dick Jahns. Jim Slosson succeeded Prof. Jahns when he moved to Penn State in the summer of 1960.
Orange County Engineering Geologist Qualifications Board (1962)
The three geologists originally appointed to the Orange County Engineering Geologists Qualifications Board in 1962 were Drs. Robert Stone, John F. Mann, and F. Beach Leighton.
Orange County Grading Board of Appeals (adopted in 1962; and amended in 1981)
An Orange County Grading Board of Appeals was created in August 1962 by Board of Supervisors Ordinance No. 3279, Grading and Excavation Code, and later defined in the Orange County Grading Manual adopted by the Board of Supervisors in 1981 (Resolution No. 81-1358). The purpose of the board was to hear and act upon appeals by property owners, their agents in control, or permittees holding grading permits to reverse or modify, or otherwise alter determinations and orders of the County’s building officials made pursuant to the procedures authorized in Section 7-1-812, Hazardous Conditions, of the Orange County Grading and Excavation Code adopted in 1962.
The members were required to include a civil engineer, soils engineer, engineering geologist, a contractor, and a layman. Nominees and one alternate for each slot were approved by the County Board of Supervisors for three year terms.
In April 1986 the Grading Appeals Board was comprised of the following individuals, with their designated alternates: civil engineers William Church and alternate Richard Hunsaker; Soils Engineers Dr. Bing C. Yen and alternate Dr. John T. Gaffey II; engineering geologists Richard Lung and C. Michael Scullin; General Engineering Contractors Charles W. Poss and Donald Gladden; and Laymen William Willis and Fred Sawyer. It is not known if Orange Country still maintains this board of appeals.