Bob Norman, water quality specialist at Lake Hemet Municipal Water District, is interested in water and history. He brings that passion to the Idyllwild Community Recreation Council’s Speaker Series in a talk and slideshow about the Lake Hemet Dam. And, according to Norman, without the dam there would have been no Hemet.
“Hemet was the first town in California to be designed on paper and the dam was critical to that design,” said Norman. In the 1880s, developers Edward L. Mayberry and William F. Whittier combined land purchases in the area of what would become Hemet with some to the west of Garner Valley in the San Jacintos to create a water source that would make development in the Hemet area possible.
A natural granite gorge at the site of the present dam at the head of a valley leading toward Hemet, made construction of the dam possible. The Mayberry Whittier group of investors planned to construct a masonry dam bridging the gorge that would create Lake Hemet, a water storage facility that would supply the nascent town of Hemet.
Norman notes engineers used blocks of granite cemented together to build the 122.5-foot-tall dam. At the time of its completion in 1895, it was the tallest masonry dam in the world. It would remain so until construction of the Roosevelt Dam in Arizona in 1911. In 1923 builders raised Hemet Dam’s height by another 12.5 feet.
The Mayberry Whittier group had purchased 6,000 acres in the San Jacinto valley. “With the dam came building of the town [of Hemet], farming, orchards and water certificates,” said Norman.
He also noted that large earthquakes in Hemet and San Jacinto in 1899 (6.4 magnitude) and 1918 (6.9) that destroyed much of the infrastructure of both towns did nothing to the dam. “Even though the [San Jacinto] fault line runs very close to the dam the way it was constructed (100 feet thick at the bottom, seated in a 13-foot trench of solid concrete) makes it very strong,” Norman said. The consulting hydraulic engineer on both Hemet and later Sweetwater Dam in San Diego County, James Dix Schuyler, said when the Hemet Dam was built, “This is a structure that will stand for all time.”
Norman wants attendees to know that his talk will not be about the city of Hemet or the Lake Hemet Municipal Water District. It will focus only on events leading up to the construction of the dam and spillway, the construction process and events that followed and affected the dam and lake.
Norman’s talk takes place at Silver Pines Lodge at 6 p.m., Thursday, Nov. 15. There is a wine and cheese reception at 5:30. Both are free to the public. The Lake Hemet Municipal Water District is co-sponsoring the event.