by Paul R. Spitzzeri
With its frequent years of low rainfall and drought punctuated by occasional intervals of heavy rains and significant flooding, greater Los Angeles’ massive growth from the late 1880s onward, especially in the suburbs, increasingly forced local leaders to confront the question of flood control.
Massive floods in the winter of 1913-14 brought the issue to the forefront and county leaders responded by creating a flood control plan on a major scale. Headed by Los Angeles County flood control engineer J.W. Reagan, the plan sought to build dams all along the San Gabriel Mountains and in other locations to protect foothill and low-lying communities from the threats posed by floods.
One area of concentration for Reagan and others in county government was the eastern section of the county in the foothill communities of San Dimas and La Verne. In mid-January 1916, some ten inches of rain fell in a two-day storm and water rushed down from the steep granite slopes of the San Gabriel Mountains and along Thompson Creek and Live Oak Canyon, the former roughly on the border of La Verne and Claremont and the latter to the west. Citrus groves were hard hit, as were residential areas in the west part of La Verne.
A project quickly coalesced to build a dam in Live Oak Canyon, north and a little east of the town. In 1920, Ross Construction Company put in a bid for just under $70,000 to construct the dam. By contrast, a much larger one slated for San Dimas Canyon to the west brought in a bid of over $600,000.
Work appears to have begun not long afterward, though the cost, not surprisingly, ballooned to about $90,000 when the Los Angeles Times reported on 29 January 1922 that
Live Oak Canyon , north of La Verne, and now in course of construction, will cost $90,000 and will only be capable of conserving 500 acre feet of storm water, but flood control engineers think the project is going to be of inestimable value to that district. The dam will be seventy feet high. It will hold back the waters of Live-oak Creek, which run[s] down the steep sides of the mountains in that vicinity and descend to San Gabriel Wash with such velocity, during heavy storms, that they frequently wash deep ravines in valuable citrus groves thereabouts.
On 3 December of that year, the Times ran a lengthy feature on Reagan’s initial efforts in dam building and flood control, specifically in the La Verne/San Dimas area, observing that
having built the Devil’s Gate [above Pasadena], San Dimas, and Live Oak Canyon dams as a starter in the great storm water control and conservation program which was launched by this county about seven years ago, J.W. Reagan, Chief Engineer of the Los Angeles County Flood Control District, has hitched up his belt another notch and is ready to put the harness on San Dimas Wash.
The article noted that, at times, the wash was only a rivulet with minimal flow, but at others, had raging flood waters creating havoc in the region. Saying the wash posed a serious problem for a half-century, the piece added that “ever since the Pomona Valley developed into the great fruit basket of the Southland, San Dimas Wash has been a public nuisance.”
Earlier in 1922, the San Dimas Canyon dam, much larger than Live Oak at twice the height and a corresponding length, was finished, but it was stated that it could not alone handle the major flows in heavy rain years and that this was a threat to San Dimas and further southwest to Covina.
Reagan’s solution, therefore, was to build a massive reservoir at Puddingstone, in the eastern end of the San José Hills stretching east of Puente out to Pomona. The natural swale there would be ideal for the storage of up to 20,000 acre-feet of water and a 140-foot high concrete dam at the northwest corner and two small earthen dams at the west end would hold the water.
The water would be brought down from the reservoir created by San Dimas Canyon Dam by a diversion channel running between San Dimas and La Verne. A water line would then go northwest for providing water for the growing town of Glendora.
A supplementary survey indicated that, when water from San Dimas Canyon was not sufficient to fill the reservoir, a tunnel could be built from the east fork of the San Gabriel River to run to Puddingstone. It was claimed that, if desired, water could be delivered to Pasadena because of the height of the reservoir site.
In addition, the dam would limit water to San Dimas Wash, emerging from the canyon and flowing southwest into Covina, and Walnut [Creek] Wash, which runs from Puddingstone southwest through a deep canyon, where the Michael D. Antonovich Trail is now, and into Covina and West Covina.
In its edition of 6 April 1923, the Times reported that members of the chambers of commerce of Covina, San Dimas and La Verne met to arrange for a celebration for the completion of the San Dimas and Live Oak Canyon dams to be held on the 21st.
The festivities at the San Dimas Dam were to include a picnic, a visit to the Live Oak Canyon Dam and to the proposed Puddingstone site, where an explanation of that project was to be given. Invitations were to be sent to other chambers, as well as fruit exchanges, packing house associations, water companies, service clubs, elected officials and others throughout greater Los Angeles, though it was added that the event was open to all.
On 9 September 1927, the Covina Argus, in an article about local flood control projects of which a massive one in San Gabriel Canyon was soon to begin, gave descriptions of the several dams in the area, including Live Oak Canyon. It observed that the dam was 70 feet high, 54 feet thick at the base and six at the top, and just over 300 feet in length. The drainage was some three square miles and there was a spillway capacity of 600 acre feet.
Shortly after that, in 1928, the Puddingstone reservoir and dam, approved soon after Reagan’s recommendations were made and with construction starting in 1923, were completed, making a significant difference to both flood control and water supply in the eastern Los Angeles County area.
Subsequent decades passed with occasional mention of Live Oak Canyon Dam, especially during the cataclysmic flooding of early March 1938 which wreaked havoc throughout greater Los Angeles. La Verne was inundated from four days of floodwaters from over 11 inches of rain rushing down from the rain-swollen San Gabriels and then being released from the opening of the flood gates at the Live Oak Canyon Dam. Business activity basically ceased and homes were surrounded by water.
Puddingstone reservoir reached 54 feet and was expected to rise further because of water released from both San Dimas Canyon and Live Oak Canyon. These canyons were reported to be virtual waterfalls because of the vast volume of water rushing down them and the pressure was such that water roared out of the channels and into the air. San Dimas Canyon Dam had so much water that it overflowed the spillway.
In early December 1966, a torrent of rainfall struck the region. It was reported in newspapers throughout the country that the reservoir was perhaps an hour from overflowing when local authorities called for the evacuation of 200 persons living below the dam, a condition that changed with the continuing suburbanization and population growth in the area. After the evacuation, flood control officials released water through a natural channel in the canyon to ease the stress on the dam and reservoir.
Today’s highlighted artifacts are a pair of snapshots taken of the Live Oak Canyon Dam in August 1925. One photo shows a man standing at the center of the dam above the spillway, while a car is on a dirt area at the other end from the photographer. The second image is from downstream of the dam and shows much of the concrete arch configuration and the central spillway.
These images are notable examples showing the early progress of the region’s emerging flood control system about a decade after initial efforts to develop plans were formulated and specifically concerning projects for eastern Los Angeles County as it grew rapidly both for residents and the highly lucrative citrus belt that stretched along the San Gabriel Mountains foothills.