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NPS Form 10-900 OMB No. 1024-0018
(Rev. 8-86)
United States Department of the Interior
National Park Service

National Register of Historic Places
Continuation Sheet

Section number 8 Page 5

St. Francis Dam (Site of), Los Angeles County, California — Narrative Statement of Significance
[continued]
Construction of the aqueduct began in 1907. Three years later, the aqueduct faced a cash shortage and a strike, which became a major
political issue during Socialist mayoral candidate Job Harriman’s campaign in 1911. Although he lost the election, Harriman’s
charges that the aqueduct water would disproportionately benefit a handful of rich San Fernando Valley land owners survived the
campaign, to become ensconced in the lore surrounding the aqueduct construction, as well as a rallying cry against the project in the
Owens Valley. It also spurred a 1912 city investigation into corruption in the building of the aqueduct. In 1913, with the completion
of the aqueduct, much of the public protest ebbed as the water began to flow. [Kahrl, 1982: 173-9]

Meanwhile, auxiliary features of the aqueduct and power generation facilities were still under construction. City voters approved the
first power plant bonds in 1910. Powerhouse No. 1 was completed in 1917, even though the initial bond referendum had failed that
year, and in 1920 Powerhouse No. 2 began to generate power. Both were located along the aqueduct, in the upper and lower reaches of
San Francisquito Canyon.

Local Water Storage and the Construction of the St. Francis Dam

Even with the completion of the Owens Valley Aqueduct, the City of Los Angeles’s water supplies remained far from assured. The
population of the city continued to grow much more rapidly than forecasted, reaching over a million by 1925. Further, the return of
drought conditions in the early 1920s caused public anxiety, and seasonal variations in irrigation use in a water system with no
effective storage capacity meant that Owens Valley water was being wasted, flushed out to the ocean during the winter.

In addition, Mulholland, who had originally advocated the continuation of limited agriculture in the Owens Valley, changed his mind
about supporting the city’s land and water rights acquisitions. With the elimination of irrigated agriculture in the upper Owens River
Valley, flows through the aqueduct increased, as did the need for seasonal storage.

The years 1924 to 1927 marked the peak of the “water wars” between the Owens Valley and the City of Los Angeles. Growing
resentment of the city by valley residents sparked often violent protests, included several dynamitings of the aqueduct. Drought,
population growth, and fear of continued insurgency, taken together combined to persuade Los Angeles officials of the need to
develop an extensive reservoir system. These proposed storage facilities were intended to fulfill a dual role: to guarantee a constant
water supply to the burgeoning metropolis, and locate the water supply a sufficient distance from the Owens Valley to provide some
measure of protection from violent acts of insurrection.

Accordingly, William Mulholland set about planning eight new reservoirs and the raising of an existing dam, effectively doubling
water storage capacity to 57,600 acre feet. Mulholland’s preferred site for the largest of these reservoirs would be Big Tujunga
Canyon, located in the San Gabriel Mountains abutting the eastern end of the San Fernando Valley. When land acquisition in the
canyon proved problematic and more expensive than anticipated, he focused his attentions elsewhere. Mulholland’s decisions from
this point forward were to prove particularly fateful to his own career, and even more so, to scores of others who played no part in
them.
As an alternative location of his principal reservoir, Mulholland turned to a site with which he’d become familiar during the
construction of the southern reaches of the Owens Valley Aqueduct ten years earlier. Thirty-five miles north of downtown Los
Angeles, the aqueduct traversed a ridge on the southern flank of San Francisquito Canyon. The canyon was also the site of two
city-owned hydroelectric plants, Powerhouse No. 1, completed in 1917, and Powerhouse No. 2, constructed in 1920.

Mulholland became at least generally familiar with the geological conditions present in the canyon during the construction of the
aqueduct. Noting the presence of unstable Pelona Schist, a “weak material, badly shattered, very susceptible to seepage of water, and
to slippage along the planes of cleavage,” in the slopes, he elected to built a 6.5 mile tunnel within the mountain, rather than the
originally anticipated hillside viaduct.