John Samuel Eastwood (1857, in Minnesota – 1924, in California) was an American engineer who built the world's first reinforced concrete multiple-arch dam on bedrock foundation at Hume Lake, California, in 1908, and was one of California's pioneers of hydroelectric power production. Eastwood's papers are held at the Water Resources Collections and Archives, University of California, Riverside.
Early life
right|thumb|[[Mountain Dell Dam]]
Born to Dutch parents in 1857 in Minnesota, Eastwood attended the University of Minnesota as a civil engineering student; prior to graduation in 1880 he headed west to work on railroad construction projects in the Pacific Northwest, including on the Northern Pacific Railroad. In 1883, he moved to Fresno, California and established an office as civil engineer and surveyor. He became Fresno's first City Engineer in 1885, but apparently was not well suited for office–bureaucratic life and soon resigned. For the remainder of his career he focused on work within the private sector or as a consulting engineer. In 1886, Eastwood began work for the Smith & Moore Lumber Company (later known as the Kings River Lumber Co.) laying out the right of way for the company's 54 mi. long lumber flume to the Sanger, Ca. lumber yards and estimating the potential yield of timber lots in the Converse Basin. Unfortunately, the financial capabilities of the company proved insufficient to meet the great cost of constructing the dam in the remote reaches of the mountains, and, as a result, Eastwood was forced to rely on an undammed, natural supply of water to drive the turbines and generators. It was this inability to impound and store runoff, along with interference in seasonal water runoff by the Fresno Gas and Electric Company, that led to the demise of the San Joaquin Electric Company in 1899 after a long drought dried up the North Fork of the San Joaquin River.