The Santa Ana River: How It Shaped Orange County

The mouth of a swollen Santa Ana River near Newport Beach and Huntington Beach, 1927. Courtesy of the Orange County Archives.

On the banks of the Santa Ana River -- at nearly 100 miles, the longest in Southern California -- the interplay between nature and culture becomes visible. Since the first humans arrived in Southern California several millennia ago, people have maintained a complicated relationship with the Santa Ana River, accepting its life-giving water but fearing its wrath. The Santa Ana shaped settlement patterns and land use at the same time that people drastically reshaped the river.

Today, like the region's other watercourses, the Santa Ana River bears little resemblance to its wilder, historical self. But -- despite being tamed by two massive dams and confined for much of its course to a concrete flood control channel -- the river remains one of the most important natural features of the Southern California landscape.

Rising in Southern California's Transverse Ranges, the Santa Ana is an ancient river; geologists suspect that the river's course predates the uplift of the Santa Ana Mountains, which the river cuts straight through at Santa Ana Canyon. Over millions of years, fed by infrequent but reliably intense storms, the river has carried sediment from the mountains and deposited on the shore, slowly forming a coastal plain that today is home to millions of suburbanites.

Story Continues Below
Support KCET

The Tongva (Gabrielino) people were among the first to live with the river they called Wanaawna, establishing several villages within sight of the willows and sycamores that lined the riverbed. The reliable water source fed the trees that grew nearby and provided shade. Several Tongva villages lined the river in the area of present-day Orange County, including the village of Hotuuknga near Anaheim and across the river from Olive. Downstream was Pasbegna near present-day Santa Ana.

Roughly once a generation, the Tongva witnessed a flood that mingled the waters of the Santa Ana with those of the San Gabriel and Los Angeles rivers and turned the coastal plain into a giant, ephemeral lake. According to an oral tradition circulated by the Luiseño people of southern Orange County, a great flood (described as a rising ocean) once covered the entire countryside, wiping out the villages on the lowlands and sparing only those camped atop the high ground of Red Hill.

The river was tame on July 28, 1769, when the first Europeans crossed it near Hotuuknga. Juan Crespí, diarist for Gaspar de Portolà's Spanish expedition, described the scene:

We came to the banks of a river which has a bed of running water about ten varas [about 28 feet] wide and half a vara [about 17 inches] deep...The bed of the river is well grown with sycamores, alders, willows, and other trees...It is evident from the sand on its banks that in the rainy season it must have great floods which would prevent crossing it...
On [the river's] right bank there is a populous village of Indians, who received us with great friendliness. Fifty-two of them came to the camp, and their chief told us by signs which we understood very well that we must come to live with them; that they would make houses for us, and provide us with food, such as antelope, hares, and seeds. They urged us to do this, telling us that all the land we saw...was theirs, and that they would divide it with us.

But when a Spanish party returned two years later with plans to establish Alta California's fourth mission on the site, the Tongva greeted their arrival with hostility. The missionaries retreated several miles to the northwest and instead established their mission -- Mission San Gabriel Arcangel -- in the San Gabriel Valley.

Eventually, the newcomers dispossessed the Tongva of nearly all their land,
and the river water that once sustained villages of hunter-gatherers came to support a series of increasingly intensive economic regimes, each one leaving a bigger environmental footprint and making more demands on the river as a natural resource.

First was the light agricultural economy of the Spanish ranchos, which introduced irrigation to the fruitful plains surrounding the Santa Ana River. As grantees of the 48,000-acre Rancho Santiago de Santa Ana, the Yorba and Peralta families were pioneers in this respect, digging canals to irrigate their fields and vineyards. The ditches -- or zanjas, as they were known in Spanish -- also provided water for the pueblo of Santa Ana Abajo (now known as Old Santa Ana) and several other adobe settlements along the river.

After the Mexican-American War, another wave of newcomers drew even more water from the river as the Mexican ranchos disintegrated in the face of new political and economic realities. In place of the sprawling cattle ranches, towns began to sprout from the Santa Ana's flood plains, nourished by the river's water and its rich soil deposits.

A group of German immigrants founded Anaheim (the name roughly means "home on the Santa Ana") as an agricultural colony in 1857. Under the supervision of their superintendent, civil engineer George Hansen, the colonists built a seven-mile canal to irrigate what some claimed was then the world's largest vineyard. The vines thrived in Anaheim's loamy soil.

River water also sustained the Mormon colony of San Bernardino (founded 1851) and the towns of Santa Ana (1869) and Riverside (1870), among others.

Agriculture became more intensive with the arrival of an important new crop: the orange. By the end of the nineteenth century, the river connected Southern California's two great orange belts, winding its way from the vast expanse of navel orange groves situated at the base of the San Gabriel and San Bernardino mountains to the Valencia groves that flourished in Orange County's lower elevations.

Water from the Santa Ana River helped make its watershed a leading agricultural region. Oranges grew both at the base of the mountains where the river rose and on the Orange County coastal plain. Courtesy of the Orange County Archives.

A series of flumes and canals carried Santa Ana River water 17 miles to Tuffree Lake (now Tri-City Park) near Placentia. Courtesy of the Placentia Public Library.

Santa Ana Canyon before flood control measures transformed the river's appearance. Courtesy of the Photo Collection, Los Angeles Public Library.

The Santa Ana River once emptied into the Newport Bay. The 1920 construction of Bitter Point Dam rerouted the river so that it bypassed the bay and emptied directly into the ocean. Courtesy of the Title Insurance and Trust, and C.C. Pierce Photography Collection, USC Libraries.

A 1961 view of the pre-channelization Santa Ana River in Santa Ana Canyon. Courtesy of the Orange County Archives.

The Santa Ana River watershed became one of the nation's most productive agricultural regions, but with each town start, grove planting, or capital investment, the river came to be seen as more of a threat. Orange County was especially vulnerable; a swollen river rushing out of Santa Ana Canyon had the potential to jump its banks where the river turns south near Anaheim. If that happened, it would spread out in a sheet over the entire coastal plain.

In 1862, that worst-case scenario came to pass.

A weather phenomenon now known as an ARkStorm had brought 40 days of nearly uninterrupted rain to Southern California, submerging much of Orange County in several feet of water. Floodwaters drowned crops and killed herds of cattle. Upstream, intensive logging in the San Bernardino Mountains magnified the flood's impact as destructive debris flows buried productive fields and wiped out entire towns. Among the towns destroyed was the ironically named Agua Mansa ("smooth water"), then the largest settlement between Los Angeles and New Mexico.

Farms recovered, and many communities rebuilt, but after another major flood devastated the watershed in 1916, residents started clamoring for protection from the river's rare but deadly fury. Noting that Orange County's population had more than quadrupled in the thirty years between 1890 and 1920, engineer J. B. Lippincott recommended sweeping flood control measures, including dams on tributaries, a widened river channel, and reinforced levees. The centerpiece of Lippincott's plan was a 70-foot dam capable of holding a reservoir of 174,000 acre-feet of water.

That structure -- Prado Dam -- would eventually get built just east of the Santa Ana Canyon, but not before one more devastating flood.

On March 3, 1938, following days of heavy rain, the Santa Ana River again flooded much of Orange County. An eight-foot wall of water roared out of Santa Ana Canyon and destroyed the Mexican communities of Atwood and La Jolla, killing 43. The violent river smashed through railroad bridges and carried houses off their foundations and into orange groves. Much of Anaheim lay underwater.

The human story of the 1938 flood is richly documented in the collections of the Center for Oral and Public History at Cal State Fullerton.

In one oral history, Eddie Castro recalls how he and his family escaped the rising floodwaters in the local schoolhouse: "The sound of breaking homes could now be heard. I remember this very well. It sounded like real large squeaks and scratches, cracks, and booms. All was very quiet. It seemed like we were just waiting to hear the next crash."

Frances Ramirez, who lived in Atwood when the floodwaters came, remembers taking refuge on high ground: "We parked on the little hill, and then we stayed in the car. Just the three boys got down [to] check and see if his dad was coming...they told us that they could see dogs and cows and pigs--and at that time they could have anything--and, houses breaking up in the water. Oh, it was ugly, ugly."

In all, the flood left more than 50 people dead and thousands homeless. Just five months later, work began on Prado Dam.

The dam's completion in 1941 would mark the beginning of a decades-long, multi-billion-dollar effort by local agencies as well as the U.S. Army Corps of Engineers to protect Orange County and upstream riverside communities from the Santa Ana River. The river's course through San Bernardino and Riverside counties preserves many wild aspects, but in Orange County work crews replaced the river's braided channel and meandering course with a straight, concrete channel and broad, sandy retarding basins.

By curbing the river's capacity to flood, the engineers' work opened up more areas to development and helped make possible Orange County's rapid postwar suburbanization--ironically magnifying the risk posed by a surging river that somehow manages to escape its shackles.

The government's long campaign to manage the Santa Ana River culminated in the massive Seven Oaks Dam, which stands 550 feet high in the river's canyon through the lower San Bernardino Mountains. When the dam opened in 2000, engineers declared Orange County safe from a 100-year flood.

Today, many who live near the once-feared river are rediscovering it as a recreational site. A paved pathway accompanies much of the river on its course, and activists hope soon to link various segments to form one continuous 110-mile trail from the mountains to the sea, allowing joggers, bikers, and equestrians to enjoy the river's surviving charms where the Tongva once strolled.

In 1916, a flooded river destroyed the Atchison, Topeka, & Santa Fe Railroad bridge near Olive. Courtesy of the Orange County Archives.

Aerial view of a flooded Santa Ana River in 1938. Courtesy of the California Historical Society Collection, USC Libraries.

Floodwaters submerged much of Anaheim in 1938. Courtesy of the Anaheim Public Library.

After the 1938 flood, local agencies built Prado Dam, visible on the center-right, just upstream from Santa Ana Canyon. Courtesy of the Orange County Archives.

1974 aerial view of the Santa Ana River near its outlet, where it is confined to a flood control channel. Courtesy of the Orange County Archives.

Many of the archives who contributed the above images are members of L.A. as Subject, an association of more than 230 libraries, museums, official archives, cultural institutions, and private collectors. Hosted by the USC Libraries, L.A. as Subject is dedicated to preserving and telling the sometimes-hidden stories and histories of the Los Angeles region. Our posts here provide a view into the archives of individuals and institutions whose collections inform the great narrative—in all its complex facets—of Southern California.

Follow us on Facebook and Twitter, and find Nathan Masters on Twitter and Google+.

About the Author

A writer specializing in Los Angeles history, Nathan Masters serves as manager of academic events and programming communications for the USC Libraries, the host institution for L.A. as Subject.
RSS icon


The Good and Bad of Changes Coming to Crenshaw High


Rain Shadow Desert: Why the Rain Often Skips The Desert