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Water Supply Development in San Diego and a Review of Related Outstanding Projects
by Mike Sholders
People create cities near water to maximize opportunities for commerce, recreation, and most importantly to ensure drinking water for the population. In San Diego County, natural streams and lakes are very small, compared to other large cities, and most are in the coastal range many miles from the metropolitan area.
San Diego is classified as a semiarid section of the United States and has so little annual rainfall that the agricultural area is continuously dependant upon irrigation. The average annual rainfall on the County’s coastal plain over the last 150 years is about 10 inches. Mountain streams provide only a limited and extremely variable water supply. Many reservoirs have been constructed to store water for use in dry years and to provide regulation of water flow. Only a few watersheds have reliable groundwater, and their wells provide only a small percentage of the water needed for the County’s large agricultural producers.
Fortunately, the early pioneers and community leaders planned for and constructed water supply facilities that were necessary to sustain the County’s population. They also had the vision to recognize the need for imported water from the Colorado River and other sources. The planning and construction of water supply facilities for sufficient imported water has been a serious issue that still remains today.
This article addresses the history of the planning and construction of the major water supply facilities that make San Diego one of the finest and most desirable cities in the world. Also, it will emphasize the role and importance of civil engineering to the water supply development in San Diego County.
The history of water utilization in San Diego County may be broken down into four periods: the Mission Period (1769-1834), the Early California Period (1835-1885), the Boom Period (1886-1895), and the Present Day Period or Planned Development (1869 to the present).
The Mission Period, from 1769 to 1834, was characterized by the efforts of the Franciscan missionaries to obtain water for the Mission San Diego de Alcala and for the Presidio. There were many attempts to obtain a good source of water supply. The first was water from the dug wells in the gravels of the San Diego River. Later efforts to obtain a good supply included ditches with sand and brush diversion dams and storage of water in small reservoirs and cisterns. These efforts culminated in the construction of the Padre Dam (Old Mission Dam) in 1816, a brick and mortar storage and diversion dam near the head of Mission Gorge and an aqueduct to carry the waters to the Mission and the Mission lands. The Padre Dam itself is still in existence. However, since its completion, some portions of the dam have been destroyed by floods.
The Early California Period, from 1835 to 1885, is best characterized by the lack of any coordinated or planned development of a water supply. From 1834 to 1872, almost all water was obtained from dug and drilled wells, both in the San Diego River and the New Town (downtown San Diego) area. In 1873, the first planned development of water was started, with the incorporation of the San Diego Water Company. During the early years of the company, water was still pumped from wells and distributed to consumers in both San Diego and Old Towns.
The Boom Period of 1886-88 saw San Diego’s population grow at tremendous rate, and the entire population seemed to think that San Diego and the County area were going to continue growing rapidly. Developers, investors, and speculators planned immense water conservation projects and, within a period of fourteen years, formed many water-related companies. These ventures included: the San Diego Land and Town Company in 1881, the Otay Water Company in 1886, Linda Vista Irrigation District also probably in 1886, the San Diego Flume Company in 1886, the Mount Tecarte Land and Water Company in 1897, the Pamo Water Company in 1888, and the Southern California Mountain Water Company in 1895.
There were numerous other plans that never had a name or reached the incorporation stage. Engineering achievements during this period include the building of the Sweetwater Dam and distribution system and the Cuyamaca Dam and flume. After the completion of Cuyamaca Dam and flume, water was purchased from the San Diego Flume Company and distributed to the populace.
A more planned period of development began after the boom was over. Only three of the companies listed above survived the drought of 1895-1904; the Otay Company, the Flume Company, and the Mountain Water Company. However, the plans of those that failed pointed the way to later developments. In fact, all the major reservoirs that are being considered for development at the present time, or that have been built, were a part of the plan of at least one of those original companies.
At the turn of the last century, the City of San Diego began purchasing some of the properties of the existing water companies to ensure a reliable water supply for its population. In 1901, the City purchased the facilities of the San Diego Water Company that lay within the City limits for $600,000. In February, 1913, it purchased the Barrett-Otay System from the Southern California Mountain Water Company for $2,500,000. In 1920, the City began purchasing water from the San Dieguito Mutual Water Company. Five years later, it purchased the San Dieguito system from the San Diego County Water Company for $3,750,000.
The City of San Diego also began building water projects itself. In 1913, the City built the Mission Valley pumping station. The following year the Bonita pipeline, eight miles of 28-inch riveted steel pipe, was installed. During the 1916 flood, the Otay reservoir dam, built of rock fill with a steel plate core, was overtopped and destroyed. In 1917 and 1918, the Otay reservoir dam was replaced with a gravity section concrete arch dam 145 feet high. Then, over the period of 1921 to 1923, Barrett Dam, a gravity section concrete arch dam 171 feet high, was constructed. Lakeside-University Heights pipe line, 17 miles of 36-inch lock joint riveted steel pipe, was installed in 1927. In that same year, the Lakeside and Riverview pumping plants were installed. Work was undertaken in 1927 through 1931 to improve the spillway at Hodges Dam. In 1928, a water filtering plant was built in University Heights, with sixteen gravity filter units. The lower Otay-San Diego second main pipeline was installed in 1929, with 8.1 miles of 40-inch electric welded steel pipe, another 8.1 miles of 36-inch pipe. The El Capitan Dam, a fill-rock embankment, 217 ft. high, was completed in 1935 at a cost of $3,000,000. These are just a few of the projects that provided a reliable water supply to San Diego County.
Early in the last century, planners began looking for sources of water beyond the local watersheds. Civil Engineers began working on the development of the Colorado River as early as 1902, when Congress enacted the Reclamation Act. A special appropriation was awarded to the Bureau of Reclamation in 1914, for intensive studies of the river basin. Civil Engineers in the U.S. Geological Service provided the basic data needed from stream gauging stations that was used to predict the amount of water available for conservation and development purposes. These studies were completed and a report compiled by the Bureau of Reclamation Project Engineer, John T. Whistler, in March, 1919.
More funds were made available for further studies in May, 1920 and the Chief Engineer for the Bureau of Reclamation, Frank E. Weymouth, directed further investigations. This resulted in a famous report known as the Fall- Davis Report that was submitted to the Senate in 1922. This report recommended the construction of the All- American Canal to serve Imperial Valley and the construction of Boulder Dam, later known as the Hoover Dam. This report was the substance of the Swing- Johnson bill authored by Senator Hiram E. Johnson and Congressman Phil Swing of California. Wemouth prepared a report in February,1924, that fixed the site of the Boulder Dam at Black Canyon. This report caught the attention of Engineers and political leaders in southern California and resulted in the formation of the Metropolitan Water District in 1928. Mr. Weymouth became the first Chief Engineer and General Manager of the Metropolitan Water District.
The Colorado River Compact was developed in 1922 by another engineer, Herbert Hoover, who was then the Secretary of Commerce. This Compact apportioned the use of the Colorado River water between its upper and lower basins, with the point of division at Lees Ferry. The upper basin states are Wyoming, Colorado, Utah and New Mexico. The lower basin states are Nevada, Arizona and California. The apportionment to each of the states was to be 7,500,000 Acre Feet per year for beneficial consumption, with a further grant to the lower basin states to increase their use by 1,000,000 acre feet per year. Arizona refused to ratify the Compact, so it applied just to the other six states. A provision in the final version limited the use of California to 4,400,000 acre feet per year, plus not more than one half of the surplus water not apportioned. The six states ratified the Compact by 1929, and the Boulder Dam Project was adopted by Congress, with the provision that applied, at the time, only to the six states. Herbert Hoover, now president, issued the final proclamation on Mar 6, 1929. Arizona finally ratified the Compact in February, 1944.
The San Diego City Council first discussed the necessity for drawing water from the Colorado River on July 25th, 1921. Dr Elwood Mead, the Director of the Bureau of Reclamation was very supportive of the idea and defined the many benefits that the City could derive by filing for a permit to obtain Colorado River water. On May 18, 1923, the Boulder Dam Association supported this concept. This group consisted of many influential citizens in southern California, and John L. Bacon, Mayor of San Diego was its first president. Following a systematic and effective campaign of public education, the demand for action was culminated on April 18, 1926, when Bacon signed an application to the State Division of Water Resources for the right to deliver 112,000 acre feet per year from the Colorado River. This application was later broadened to include the County of San Diego.
Two contracts assured the benefits of the Hoover Dam and Lake Mead to the City and County of San Diego. The first, the result of much effort by San Diego’s Civil Engineer H.H. Savage, was executed on February 15, 1933 and provided 250,000 acre feet of capacity in Lake Mead and for the delivery of 112,000 acre per year to San Diego at a point in the river immediately above Imperial Dam. The second achievement by Mr. Savage, in co-operation with Congressman Phil D. Swing, dated October 2, 1934, provided for the construction a diversion dam, main canal and appurtenant structure for the all American Canal to satisfy the 153 cubic feet per second (cfs) allotment of lake-river water for San Diego.
Construction of an aqueduct to bring Colorado River water to the Los Angeles area began as soon as work on Boulder Dam was under way. As financed and constructed by the Metropolitan Water District of Southern California, the Colorado River Aqueduct is designed, with some ultimate enlargement, to deliver 1500 cfs to the District’s present fourteen constituent areas and to other areas that may become annexed to the District. The Aqueduct was completed and placed under operation in 1941, at a cost of $190,000,000.
However, this did not get the water to San Diego. World War II caused a great increase in water consumption in San Diego, and it became imperative to bring Colorado River as soon as possible. The Bureau of Reclamation completed studies in 1943, comparing the costs of two possible connections for linking with the Los Angeles area aqueduct. An office was opened in Escondido and field surveys were completed.
In early 1945, military establishments, war industries, and war housing projects were using over 50 per cent of the water being delivered to consumers from the San Diego water system, and a threatened shortage in the City water supply had become a problem of national importance. An interdepartmental committee was appointed by the President of the United States to study the water supply of the city and to recommend a plan for securing a supplemental supply. The report of the Committee was published as Senate Document No. 249, 78th Congress, 2d Session. It recommended the immediate construction by the Federal Government of an aqueduct connecting with the Colorado River Aqueduct near San Jacinto, with the War Department, the Navy Department and the Federal Works Agency bearing the cost (estimated at $17,500,000). The recommended emergency aqueduct was to have a design capacity of 85 cfs. Tunnels and other permanent structures were to be constructed with a design capacity of 165 cfs, provided the bids to be received for such portions of the project indicated an increase of cost no greater than would warrant this action. The report further recommended “that the San Diego County Water Authority or the City of San Diego continue and press negotiations with the Metropolitan Water District of Southern California to the end that an equitable arrangement be worked out, which would make possible permanent service by way of route 1 (the emergency aqueduct connection) in order that the value and permanent utility of the emergency work may be realized, and to protect against the possibility of an interruption in the supplemental water supply on the termination of the war emergency.” The committee’s report and recommendations, dated October 21, 1944, were accepted by the President of the United States. Directives were issued to the departments concerned to proceed with construction. After welcoming some opposition from other Federal Agencies, construction began in the fall of 1945.
The San Vincente Aqueduct was designed as a gravity conduit, tapping the Colorado River Aqueduct of the Metropolitan Water District at the westerly portal of San Jacinto tunnel, and extending in a southerly direction to discharge into San Vincente reservoir. The total length is 71.1 miles, of which 30.4 miles are in Riverside County and 40.7 miles are in San Diego County. From the regulating reservoirs near the San Jacinto tunnel to San Vincente reservoir consists of pipelines and tunnels are of sufficient size to carry the full capacity of 185 cubic feet per second. The San Diego Aqueduct was completed and place in operation in December 1947, providing for about one half of the ultimate capacity needed. Construction of a second barrel was completed by the County Water Authority in 1954 and a second aqueduct was completed in 1958.
One unique feature of the San Diego Aqueduct is that the elevation at the Lake Mathews Metropolitan Water District connection is so high that all of the deliveries to the member agencies are by gravity so that pumping is never required. The quality of water from the Colorado River depreciates each year with regard to total dissolved solids, affecting water hardness, and is approaching unacceptable limits. Therefore, further river water from the California Aqueduct is needed to improve quality. Other sources of water such as seawater distillation and wastewater reclamation are constantly being evaluated. So far, these supplies are either too expensive or not acceptable as portable water.
The San Diego County Water Authority, consisting of five cities, three irrigation districts and one public utility district, was organized June 9, 1944, under an enabling act of the California State Legislature known as the County Water Authority Act. The primary purpose was to import Colorado River water to San Diego County. The Water Authority staff consists of 34 Board Members and a staff of Engineers that occupy a $16,000,000 facility in San Diego and a smaller field office in Escondido. These engineers and staff are busy planning new projects that will improve the reliability of the system to accommodate the predicted population to the year 2050.
The California Aqueduct became a second major aqueduct system to bring water to Southern California. It captures water from the Feather River, funnel its south through the Sacramento/San Joaquin Bay-Delta, feeds it into the California Aqueduct, pumps it over the Tehachapi Mountains, and delivers it to reservoirs near the Antelope Valley north of Los Angeles. This aqueduct, also called the State Water Project launched a bitter north-south controversy. Northern Californians asked, “Why should the southerners be allowed to steal our water?” Southern Californians countered, “It’s not their water; it’s California’s water and we’re all Californians. Eventually, under the leadership of Governor Pat Brown, the State Water Project was built, and it started delivering water to Southern California. With that new resource, both the County Water Authority and the Metropolitan Water District could make good on their commitments to provide water to new areas - for a while. One controversial component of the original plan, a “Peripheral Canal” around the environmentally sensitive Delta, was never built. As a result, the State Water Project has never delivered as much water as originally intended. The effort to find an alternative method to deliver the full contracted amount continues to this day. Concern over environmental and ecological degradation in and around the Delta complicates the problems. During the 1990’s, Governor Pete Wilson and President Bill Clinton initiated an unprecedented collaboration of state and federal agencies, as well as urban, agricultural, and environmental groups, to develop a long-term solution that restores the Bay-Delta as both a reliable water supply and a healthy habitat for fish and wildlife. This collaborative body became known as the CalFed Bay-Delta Program. San Diego County hopes to benefit from that solution with a more reliable water supply and higher-quality drinking water.
Since the State Water Project supplemented water supplies from the Colorado River, San Diego County now relies on imported water for 75 to 95 percent of its total supply. In 2002, almost three million people living and working in San Diego County depend upon the County Water Authority to make the investments necessary to secure and deliver a reliable water supply. The Authority and its member agencies finance and maintain the water supply and delivery system necessary to support the near 90 billion a year economy and quality of life enjoyed in San Diego County. Significant milestones in planning for the future include a water conservation and transfer agreement between County Water Authority and the Imperial Irrigation District that will provide up to 200,000 acre feet per year until the year 2073. This agreement represents that largest long-term water transfer in the U.S. history. Also part of future planning is the Emergency Water Storage Project, a system of reservoirs, pipelines and other facilities to increase emergency storage and pumping capabilities critical to the reliability of water supply. This action will ensure the region has enough water and flexibility to deliver the water during potential disruptions due to draught, earthquakes of other disasters.