JSDH article page 169

Water was vital to the city's growth, and Frank Kimball joined with the railroad's San Diego Land and Town Company to build the dam on the Sweetwater River that he had envisioned since 1868. When finished on April 7, 1888, at 90 feet in height, it was 20 feet higher than any other masonry dam in the country. Excursion trains on the new NC&O railway brought people to marvel at the structure. The reservoir was not filled until the legal case of George Neal was settled, compensating him for the loss of his land that would be covered by the rising water. In 1902 the dam was taken over by the Sweetwater Water Company that raised the height of the central dam in 1911 to 110 feet. It held fast in the great rains of 1916 that destroyed the Otay dam, although both ends of the Sweetwater dam made of earth and rock gave way. The water from the reservoir brought prosperity to the citrus and olive groves that filled thousands of acres of Kimball's National Ranch. However, it would be decades before water pipes reached every home, and horse-drawn water wagons were a common sight in the city streets.

Sweetwater Reservoir fills the valley behind the dam.