CS1A - Concurrent Session 01A: 1883 Disaster at English Dam

Eureka! The discovery of gold in California in 1848 and the ensuing California Gold Rush instigated an early period of dam building throughout the state. As hydraulic mining methods became more popular, more dams were needed to supply water for those seeking their fortune. English Dam, constructed in the mid-1850’s on the Middle Fork of the Yuba River, was one of those dams. Completed in 1857 and repaired and raised in the mid-1870’s, the dam was composed of three timber crib and rockfill structures. The middle dam, the largest of the three, was over 100-feet tall and 300-feet long. On the morning of June 17, 1883, two violent explosions were heard (Dynamite? Sabotage!), and a breach was seen in the upper cribwork of the middle dam. The breach continued to enlarge, and, within an hour, nearly the entire contents of the reservoir were emptied, estimated at over 13,000 acre-feet of water. The resulting flood wave caused a rise of 40-feet at a point 43 miles below the dam. Although some property damage was reported, no casualties were known to have occurred as a result of the dam failure. The 1883 English Dam failure was followed shortly after by the 1884 Sawyer Decision (Woodruff v. North Bloomfield Gravel Mining Company), which brought an end to hydraulic mining in California, and is widely considered to be the State’s first environmental law. This case study will (1) highlight information about the history and construction of English Dam, (2) describe the 1883 failure, including downstream consequences, and (3) briefly discuss dam building in California during the Gold Rush era and the fallout of the 1884 Sawyer Decision as it related to dam and levee safety.