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John Samuel Eastwood

From Alfawiki
John Samuel Eastwood
Born1857
Minnesota, United States
Died1924
California, United States
OccupationEngineer
Known forConstructing the first reinforced concrete multiple-arch dam; advancing hydroelectric power generation in California

John Samuel Eastwood (1857, Minnesota – 1924, California) was an American engineer recognized for constructing the first reinforced concrete multiple-arch dam founded on bedrock at Hume Lake, California, in 1908. He played a crucial role in advancing hydroelectric power generation in California. His professional documents are preserved at the Water Resources Collections and Archives, University of California, Riverside.

Early life

Eastwood was born in Minnesota to Dutch immigrant parents and pursued civil engineering studies at the University of Minnesota. Prior to earning his degree in 1880, he contributed to railroad construction efforts across the Pacific Northwest, including work on the Northern Pacific Railroad. In 1883, he relocated to Fresno, California, where he established a civil engineering and surveying practice. Two years later, in 1885, Eastwood became Fresno’s inaugural City Engineer but soon resigned to concentrate on private consulting and engineering projects. By 1886, he was employed by Smith & Moore Lumber Company (which later became Kings River Lumber Co.), where he surveyed a 54-mile lumber flume route to Sanger, California, and assessed timber resources within Converse Basin.

In early 1895, Eastwood assumed the role of chief engineer at the San Joaquin Electric Company, overseeing the design and construction of one of California’s earliest hydroelectric facilities. As reported in the April 1896 issue of the Journal of Electricity, he implemented emerging long-distance alternating current transmission technology to supply power to the Fresno vicinity. This plant established records for penstock head height (1,410 ft.), transmission distance (35 miles), and high-voltage three-phase output (11,000 volts). Nevertheless, financial limitations hindered dam construction in remote mountainous locations, necessitating reliance on natural undammed water flows for turbine operation. The inability to store runoff water combined with seasonal water diversions by Fresno Gas and Electric Company led to the San Joaquin Electric Company's collapse in 1899 after an extended drought depleted flow from the North Fork of the San Joaquin River.

Big Creek Complex

Eastwood served as engineer for the Pacific Light and Power Company, where he designed a significant hydroelectric initiative along the South Fork of the San Joaquin River—currently known as the Big Creek Hydroelectric Project, managed by Southern California Edison. The enterprise was controlled by financier and electric railway entrepreneur Henry E. Huntington, along with partners A.G. Wishon, Alan C. Balch, and William Kerckhoff. Eastwood’s plans included storage dams intended to guarantee steady power supply during dry periods.

Although his designs predated 1907, construction was postponed due to financial turmoil caused by the Panic of 1907. During this delay, Eastwood developed an innovative cost-effective reinforced concrete dam design that minimized material usage and expenses. In 1908, he engineered and constructed the groundbreaking Hume Lake Dam for the Hume-Bennett Lumber Company in the Sierra Nevada mountains. Finished in 1909, this project validated the practicality of multiple-arch dam structures. Shortly thereafter, Eastwood secured a commission to design a comparable dam to replace the 1884 Big Bear Valley Arch Dam near San Bernardino.

Although Eastwood planned to implement multiple-arch dams at Big Creek, he was dismissed from the project in November 1910. Initially granted 5,400 shares in the newly formed Pacific Light and Power Corporation, he forfeited these shares after failing to pay a $5 per share assessment in 1912, which compelled him to surrender his ownership stake. At age 53, Eastwood faced limited financial resources and subsequently dedicated himself to further developing multiple-arch dam designs as his professional focus.

Multiple arch dams

During the early 1900s in Salt Lake City, critical water shortages led to bond measures in 1914 to finance the construction of three storage dams, notably the substantial Mountain Dell Dam located in Parley's Canyon, which was developed between 1914 and 1925.

By this period, Eastwood had already completed four dams in California and established a reputation as an expert dam engineer. He contributed articles to Western Engineering detailing projects such as Big Bear Valley Dam, Los Verjeles Dam in Yuba County, and Kennedy Dam near Jackson, including a special promotional insert in the March 1915 edition.

Following the initial construction of Mountain Dell Dam, Eastwood broadened his involvement in water management and dam engineering throughout California, Idaho, Arizona, Mexico, and British Columbia. Known for his practical approach, he continued active fieldwork until his accidental drowning near Fresno in August 1924 at age 67. He was interred at Mountain View Cemetery, a site he had originally mapped out as Fresno’s inaugural City Engineer.

The Eastwood generating station at Shaver Lake, California, named to honor him, is a 200 MW underground pumped-storage hydroelectric facility carved into solid granite and completed in 1987.

Work

Throughout his professional life, Eastwood engineered 17 dams: one each in Utah, Arizona, and British Columbia; two in Idaho; and twelve within California. Among his most significant projects are:

External links

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