Please Add to the blog of Dam Disasters that occurred in January.
“Lower Otay Dam Disaster – United States (1916) – Death Toll: 40
The Lower Otay Dam constructed on Otay River is situated in San Diego County, California, United States. Its purpose was to serve as a large water reservoir.
In January 1916, after a heavy rain spell hit on the southern region of California, the dam topped up and started releasing water. Unfortunately no proper rescue measures were taken and the reservoir emptied causing great damage in the nearby areas.”
via Top 15 Worst Dam Disasters Ever.
The dam failed at the right abutment on 27 January 1916. It was a earth and rock fill dam with a steel core.
“Lower Otay Lake and Dam is a rock fill structure with a massive masonry pour as a base for the steel plates. The steel plates, riveted together, acted as a diaphragm to control seepage and can be seen at the middle of the dam. A pyramid formed by the steel members during construction was used as a crane to move rock, steel and concrete to their proper location in the structure. Explosives were used to break rock into smaller units for use in the dam. As an example of the effect of blasting, records show that 100,000 pounds of powder loosened 150,000 tons of rock.”
https://www.sandiegohistory.org/journal/2002-1/hill.htm