Santa Ana River

The Santa Ana River rises in the southern San Bernardino Mountains, at the confluence of two tiny streams, Heart Bar Creek and Coon Creek, at an elevation of . Its highest sources are Dollar Lake, at , and Dry Lake, at , both on the northern flank of San Gorgonio Mountain, at the headwaters of the South Fork Santa Ana River. The river flows west through a wide, deep and heavily forested mountain valley. About from its headwaters, it receives its first major tributary, Bear Creek, which enters from the north. Bear Creek receives its water from Big Bear Lake, a popular recreational mountain lake. The river turns south, passing through the Seven Oaks Dam, and reaches the arid Inland Empire lowland covering large parts of San Bernardino County and Riverside County. It receives Mill Creek from the south and passes to the south of San Bernardino, then receives City Creek from the north and San Timoteo Creek from the south. Due to water diversions for groundwater recharge, the river bed is usually dry in this stretch between Mill Creek and the outlet of the Veolia water treatment plant north of Riverside, which restores a year-round flow. From there to Prado Dam the river supports a riparian zone with considerable greenery. Not far below the confluence with San Timoteo Creek, Lytle Creek enters from the north. Lytle Creek is one of the largest tributaries of the Santa Ana river, rising from three forks in the San Gabriel Mountains and flowing southeast, before emptying into the Santa Ana River as Lytle Creek Wash. From there, the river turns southwest, and after passing through western Riverside, it discharges into the normally dry flood control reservoir formed by Prado Dam. Two major tributaries of the river join in the reservoir area: Chino Creek from the north, and Temescal Creek from the south. Temescal Creek drains the largest area of all the tributaries, because it provides the outflow from Lake Elsinore, into which the San Jacinto River flows. It is also one of the longest, at in length. Except during the wettest years when Lake Elsinore fills high enough to overflow, Temescal Creek contributes little to no water into the Santa Ana River. Below Prado Dam, the Santa Ana River crosses into Orange County, and cuts between the Santa Ana Mountains and Chino Hills via the narrow Santa Ana Canyon. The river roughly bisects the county as it flows southwest towards the ocean. In Anaheim, the entire flow of the river (except during wet seasons) is diverted into spreading grounds for groundwater recharge of the north Orange County aquifer, providing about half of the county's municipal water supply. Downstream of there, the river is mostly confined to a concrete channel, serving only for flood control and urban runoff drainage, and is usually dry or a small trickle. At Orange it receives Santiago Creek from the east before entering Santa Ana. After crossing under Interstate 5 it passes through the River View Golf Course, one of its few non-concreted sections within Orange County, and then becomes a concrete channel again through most of Santa Ana and Fountain Valley to a point below the 405 Freeway, where the river bed becomes natural (though the banks remain concrete). The mouth of the river is located in a small tidal lagoon between Huntington State Beach in Huntington Beach and Newport Beach. ==Watershed==

The Santa Ana River drains the largest watershed of California's South Coast region, The southern part of the watershed, drained by the San Jacinto River into Lake Elsinore and via Temescal Creek into the Santa Ana River, constitutes some 45% of the total area and extend its boundaries as far south as the Colorado Desert at Anza-Borrego Desert State Park. The river has over 50 named tributaries, most of which are intermittent streams. As of 2000, about 4.8 million people lived in the Santa Ana River watershed. Most of the population is concentrated close to the river in urban centers such as San Bernardino, Riverside, Anaheim and Santa Ana. The Inland Empire still has large areas dedicated to agriculture and ranching, although it is rapidly urbanizing. In Orange County, nearly all the valley lands are urbanized. Some major bodies of water in the watershed include Irvine Lake, Lake Mathews, Lake Perris, Diamond Valley Lake, Lake Skinner, and Big Bear Lake. All of these are water supply reservoirs constructed by county or state water agencies, and with the exception of Big Bear, much of the water is imported from other parts of California due to the arid local climate. Further south, in San Diego County, the watershed is bordered by those of San Mateo Creek, the Santa Margarita River, and the San Luis Rey River. On the east the watershed shares borders with those of the Whitewater River and the Coachella Valley, flowing into the Salton Sea, because the surrounding land slopes away from the river bed. In its natural state the river would frequently change course into one of many intermittent channels that fan out across the plain. Today, these auxiliary river-beds have been artificially disconnected from the Santa Ana River and converted into flood control channels, including the Talbert and Huntington Beach channels, which empty into the Pacific very near the mouth of the Santa Ana River. The combined Talbert-Huntington Beach watershed drains of mostly suburbanized land. The river originally had many different outlets to the Pacific, one of which even extended as far north as the San Gabriel River. The original mouth of the river was located at Newport Bay, which drained into the Pacific Ocean, at what is today the entrance to Newport Harbor. Based on a U.S. Coastal Survey from 1878, Newport Bay was predominantly a river estuary with few open channels. The river flowed into the bay bringing with it heavy silt and making boating difficult. To eventually create Newport Harbor, sand deposited by the Santa Ana River had to be constantly dredged away. In 1920, the Bitter Point Dam was built to divert the river away from the bay and on its current course to the ocean at Huntington Beach. Stone jetties were built to form the new river mouth. All of the Islands in Newport Harbor are the product of dredging and man made forming from the sands and silt deposited over time by the Santa Ana River. ==Geology==

is in the background. Ancient igneous, metamorphic and sedimentary rock underlie and form the geologic base of the Santa Ana River watershed. Most of the strata in the flat valleys and basins of the watershed are underlain by thousands of feet of sediment deposited by shallow seas that covered parts of Southern California in ancient times. Most of the mountains in and around the basin consist of granite batholiths about 75 million years old. This rock originally formed at the bottom of the ancestral Pacific Ocean and was uplifted to the highest peaks of the mountains by tectonic action. Even during the ice ages, Southern California mountains were not subjected to extensive glaciation, so the rock has remained for tens of millions of years without significant erosion. The Elsinore–Whittier Fault Zone crosses the Santa Ana River further downstream, near the Orange/Riverside County line. While the Transverse Ranges rise above in many places, the highest peaks of the Peninsular Ranges reach less than half that elevation. The canyon was eroded through bedrock that today divides the groundwater basins of the Inland Empire and the coastal plain. Because groundwater in the watershed generally flows from east to west, it is forced to the surface at the bedrock "sill" of Santa Ana Canyon, resulting in a perennial stream that prior to development flowed freely across the coastal plain to the Pacific. During this period, the Santa Ana changed course multiple times, eroding now-dry wind gaps in the Peninsular Range and the coastal mesas around Huntington Beach and Newport Beach. ==Ecology==

Hundreds of species of animals and plants characterize the Santa Ana River's diversity of climates and vegetation zones. There are over ten of these vegetation zones in the watershed—including the sparsely vegetated alpine and subalpine zones in the mountains, mid-elevation forests of pine, lodgepole and oak, chaparral, coastal sage scrub, the increasingly rare riparian forest and marshes along the river bed, lined with trees and rushes, and the thinly vegetated coastal areas virtually flush with sea level. The watershed supports up to 200 bird species, 50 mammal species, 13 reptile species, 7 amphibian species, and 15 fish species, including steelhead trout. The largest portion of the watershed, the Inland Empire portion, is dominated by a hot, dry desert climate that supports sparse wildlife, while the climate and vegetation of the San Jacinto River and Temescal Creek watershed is similar to that of the southern Central Valley. Downstream of the desert was once the coastal sage scrub and dry grassland community of the Orange County coastal plain, but that region has been almost entirely lost to urbanization. Rimming the arid portions of the watershed are the chaparral zones, consisting of sclerophyllous, thick, low bushes and small trees. The chaparral generally is found between elevations of , and occurs mainly closer to the coast on the windward side of the Peninsular Ranges. The scrub oak is one of the most common plants in chaparral regions, forming a dense groundcover that makes it difficult for humans and large animals such as mountain lions, coyotes, and bobcats to traverse. Chaparral growth is determined by wildfires and droughts, and depends on the semi-arid climate of the region. Perennial and seasonal streams often are lined with live oak and sycamore, which transition into the riparian zones of the main stem Santa Ana River. The largest unbroken riparian corridor is the stretch between Riverside and Prado Dam, where the river has been largely left in its natural state despite pollution from urban runoff. In addition, the flood control basin behind Prado Dam contains of seasonal wetlands. The Santa Ana sucker, a small bottom-dwelling fish, was once found along most of the Santa Ana River, but is now rarely seen. Near the mouth, the river was once abundant in salt marshes, which stretched for miles on either side of the river, even near Upper Newport Bay, which has also served as an alternate mouth of the river. The alpine and subalpine zones, despite their high elevation (above ) and significant rainfall (at least per year, except in drought years), are sparsely vegetated. The windswept terrain of the alpine zone is primarily small brush and weeds, while trees—mostly small gnarled pines and junipers—occur in canyons and shielded depressions in the subalpine zone. Inland elevations above support much denser forest. Jeffrey pine, ponderosa pine, black oak, lodgepole pine, and willow constitute most of the forested lands. The mountain habitats of the watershed support many animals typical of Californian mountain regions, including squirrels, chipmunks, black bears, mule deer, and many species of migratory birds. In the canyons of the San Bernardinos, the river is abundant in rainbow trout and is lined with alders, willow and cottonwoods. Where the river and its large upper tributaries empty out of the mountain canyons into the Inland Empire basin, they are surrounded by the alluvial scrub zone, a mix of desert and upper riparian vegetation. Along the main stem, this zone begins at the base of Seven Oaks Dam and ends at the Lytle Creek confluence. The steelhead is an anadromous fish, similar to salmon, that migrates up rivers and streams to spawn. Unlike salmon, which usually only reproduce once, steelhead may reproduce multiple times and have a much longer life span. Steelhead was once found along the entire main stem of the Santa Ana River, as well as on some of its main tributaries—Santiago Creek, San Antonio and Chino Creeks, Cucamonga Creek, Lytle Creek, City Creek, and Mill Creek. Few, if any, steelhead were present in Temescal Creek (although one of its tributaries was stocked in the 1930s There is a population of wild stream resident coastal rainbow trout upstream of Seven Oaks Dam and in the upper reaches of a few tributaries. Invasive species—those that are not native to the region—have caused problems in the watershed for many years. One of the most troublesome invasive species is the giant reed, which plagues many coastal Southern California waterways. The giant reed is similar to a tall grass or thin bamboo, but grows quickly and can take over native stands of vegetation, block the streambed, hurts the habitat of native animals, and increases the hazard of wildfires. Perhaps the largest effect that giant reed has is its usage of water. To support its fast growth rate, the giant reed population in the Santa Ana River watershed can consume of water per year. Other invasive species also have affected the Santa Ana River. One of the most prominent is the brown-headed cowbird, which feeds off parasites and insects identified with cattle, which were brought to Southern California during the Spanish Rancho period. The brown-headed cowbird is a "brood parasite", or a bird that lays its eggs in another bird's nest. One of the most afflicted birds is the least Bell's vireo, whose population also suffers from the loss of riparian habitat. The least Bell's vireo is considered an endangered species, as is the southwestern willow flycatcher, whose habitat is often shared with the other bird. ==History==

First peoples Human habitation on the Santa Ana River dates back 9,000 to 12,000 years ago, close to the early stages of the Holocene period. The first Native Americans to live in the area were nomadic tribes that traveled from place to place, grazing animals on fertile grasslands and gathering fruits and seeds for food. The ancestors of these early people originated from the Shoshone and Uto-Aztecan people of the northwestern United States. Eventually, the human population of the watershed reached a peak of about 15,000. About 8,000 years ago, the climate experienced a change becoming more arid and the originally nomadic tribes began to stay in individual places longer, becoming semi-nomadic. However, they did not establish agriculture, nor did they raise animals or live in villages. Several major premodern Native American groups eventually gained control of lands along the river: the Yuhaviatam or Yuharetum people in the upper basin, the Payomkowishum in the southeastern basin, the Cahuilla in the desert areas of the watershed, and the Tongva people in the lower basin. The Yuhaviatam generally lived in the mountain headwaters of the Santa Ana River and its tributaries rimming the present-day Inland Empire basin, in present-day San Bernardino County, as well as in the foothills of the San Bernardino Mountains. Spanish period in 1835 When Spanish explorer Juan Rodriguez Cabrillo sailed along the Southern California coast on his voyage of 1542, he passed the mouth of the Santa Ana River without noting it. Although no missions were actually located along the Santa Ana River or within the watershed, the river basin was nearly depleted of native people because the Spanish forced them to work at nearby missions, including Mission San Gabriel Arcangel and Mission San Luis Rey. The affected tribes were usually renamed after the missions, resulting in tribal names such as Gabrieliño and Luiseño. Difficult working and living conditions and European diseases such as smallpox killed much of the native population during the roughly 50-year-long Mission Period. The Secularization Act of 1833, passed by the newly independent country of Mexico, eventually brought an end to the Mission Period. The post-Mission Period native population was almost entirely devastated. The population was very little, their native religions were nearly lost, and most of their land had been taken by Spanish settlers. Other ranchos on the river followed, including ones in inland areas that had not been exploited in the Mission Period. Spread throughout the ranchos on the Santa Ana River were a few towns, military outposts and trading posts. The Santa Ana River valley was one of the most prosperous regions in Southern California for many decades. American settlement In the late 1840s, California fought for its independence from Mexico in the Mexican–American War. The Santa Ana river played an important part in the victory of the Americans over the Mexican army. In 1847, one year after the Bear Flag Revolt, a Mexican military force set out northwards to attack a smaller American force in the Los Angeles area. However, the Santa Ana River flooded, preventing the Mexicans from crossing the river to attack the Americans. When the river's flow finally subsided, the American forces had been reinforced enough to drive the Mexicans out of the region. When the California Republic was assimilated into the United States in 1848, American settlers began to move into the Santa Ana River region in great numbers. The Mexican ranchos were divided into smaller individual properties, and irrigated agriculture began on a large scale. The city of Santa Ana Viejo, the original location of Santa Ana, was founded in this period. In 1854, Mormons settled in the upper Inland Empire area and started the city of San Bernardino, gaining prosperity by using water from the river, as well as Lytle Creek and Mill Creek, to irrigate crops. The levees along the river burst in many places, flooding part of the Inland Empire into a continuous body of water several miles wide stretching from the mouth of Santa Ana Canyon to where the river cuts through the Santa Ana Mountains. Downstream in Orange County, the river overwhelmed nearly all the existing floodworks and transformed the coastal plain into a transient inland sea. The flow, now calculated as a 1,000-year flood, peaked at roughly , over half the average flow of the Mississippi River. Even after the flood, detrimental conditions continued in the region. For the two years following the flood, an intense drought caused the deaths of tens of thousands of head of livestock. Despite all of the hardships experienced in the three years, after conditions finally returned to normal, the Santa Ana River watershed again became a prospering agricultural region. 1934 and 1938 saw a further pair of devastating floods that in part brought an end to the area's citrus industry. In the Los Angeles flood of 1938, the Santa Ana again burst its banks and flooded Anaheim and Orange in up to of water, stripping away thousands of acres of rich topsoil and destroying many of the citrus groves. Almost 60 people were killed in the disaster and about of land were flooded, With the extreme damage from the floods, the U.S. Army Corps of Engineers made the decision to dam and concrete the river beginning in the 1940s, and declared it as the greatest flood hazard in the U.S. west of the Mississippi River. With the increased flood protection afforded by the Prado Dam, major industrial development migrating south from the Los Angeles Basin, and the Southern California housing boom in the 1950s and 1960s, the Santa Ana River watershed began its third and final transition—from agricultural to urban. In 1964, the Santa Ana River Mainstem Project, which involved concreting the lower of the river, was first proposed. Construction work began in 1989, and today, through much of Orange County, the river's channel is essentially an enormous box culvert. The second dam, Seven Oaks Dam, was completed in 1999. This dam captures flood runoff from Santa Ana Canyon before it can enter the Inland Empire. Today, the river lies mainly between levees and concrete channels, and especially in its lower course, functions only as a flood drainage channel. ==Pollution and restoration==

As with many Southern California rivers, the Santa Ana is heavily polluted and used. The main stem above Seven Oaks Dam is free-flowing, as are many of its upper tributaries. Once the river enters the Inland Empire basin, however, much of its flow is diverted for municipal and agricultural water use. Most of the flow in the river below the city of San Bernardino consists of effluent from 45 wastewater treatment plants and dry season urban runoff, which is collected behind Prado Dam. Any flow that makes it downstream to Orange County is diverted by another pair of dams into approximately of groundwater recharge basins, providing approximately of municipal water for the county every year, or one-third of its water supply. Downstream of that dam, the river gathers further urban runoff before finally making it into the Pacific. A number of organizations have been formed to try to gain public interest in restoring the river. One of the most prominent is the Santa Ana Watershed Project Authority (SAWPA), formed by five municipal water districts in the Santa Ana River area. A second one is the Santa Ana River Dischargers Association. Both have conducted studies as to what beneficial uses the Santa Ana River would have aside from water supply and flood control, as well as the removal of some of the concreted sections of the lower river. This set of studies is known as the "Use-Attainability Analysis", which was submitted to the state Congress, which approved it. However, upon submission to the EPA, it was rejected. As a result, little work has been done to repair the ecological damage that has been caused by urbanization along the river. Other projects include the Santa Ana Watershed Planning Advisory Committee, ==Recreation==

There are many recreational opportunities along the Santa Ana River. The Santa Ana River watershed includes parts of the Cleveland National Forest, San Bernardino National Forest, Angeles National Forest, Mount San Jacinto State Wilderness Area, Chino Hills State Park, and Lake Perris State Recreation Area. Big Bear Lake, Lake Elsinore, and Lake Irvine are popular recreational lakes in the watershed. The river never actually flows through any of these lakes, but they each have drainage to the river via tributaries. The Santa Ana River bicycle path which, when complete, will run from the river's mouth at Huntington Beach to near the San Bernardino Mountains, currently extends about along the river to Prado Dam. The proposed distance along the trail is over . In Riverside County, the Hidden Valley Wildlife Area also has of recreational paths. Some entities have been opting for a Santa Ana River Park, which would encompass a strip of land on either side of the river for its entire course. The city of Redlands would like to develop riverside green space near the historic downtown district. ==Crossings==

The Santa Ana River has 70 significant crossings, bridges and dams. This list places them from mouth to source. ===Orange County=== • State Route 1 (Pacific Coast Highway) (Newport Beach/Huntington Beach) • Victoria Street/Hamilton Avenue (Costa Mesa/Huntington Beach) • Santa Ana River bicycle path (Costa Mesa/Huntington Beach) • Adams Avenue (Costa Mesa/Huntington Beach) • Interstate 405 (San Diego Freeway) (Costa Mesa/Fountain Valley) • Talbert Avenue/MacArthur Boulevard (Santa Ana/Fountain Valley) • Slater Avenue/West Segerstrom Avenue (Santa Ana/Fountain Valley) • Warner Avenue (Santa Ana/Fountain Valley) • Harbor Boulevard (Santa Ana) • Edinger Avenue (Santa Ana) • McFadden Avenue (Santa Ana) • Bolsa Avenue/1st Street (Santa Ana) • 5th Street (Santa Ana) • Former Pacific Electric Railway Railway Bridge (future OC Streetcar) • Fairview Street (Santa Ana) • Westminster Avenue/17th Street (Santa Ana) • Santa Ana River bicycle path (Santa Ana) • Garden Grove Boulevard/Memory Lane (Orange/Santa Ana) • State Route 22 (Garden Grove Freeway) (Orange) • Interstate 5 (Santa Ana Freeway) (Orange) • Chapman Avenue (Orange/Anaheim) • Orangewood Avenue (Orange/Anaheim) • State Route 57 (Orange Freeway) (Orange/Anaheim) • Metrolink Orange County Line & Amtrak Pacific Surfliner (Orange/Anaheim) • Katella Avenue (Orange/Anaheim) • Railroad Bridge (Orange/Anaheim) • Taft Avenue/Ball Road (Orange/Anaheim) • Lincoln Avenue (Orange/Anaheim) • Glassell Street/Kraemer Boulevard (Orange/Anaheim) • Metrolink Inland Empire–Orange County Line (Anaheim) • Tustin Avenue (Anaheim) • State Route 91 (Riverside Freeway) (Anaheim) • Lakeview Avenue (Anaheim) • State Route 90 (Imperial Highway) (Anaheim) • Santa Ana River bicycle path (Anaheim) • Weir Canyon Road (Anaheim/Yorba Linda) • bnsf railway bridge • Gypsum Canyon Road (Yorba Linda) ===Riverside County=== • Green River Road (Corona) • Metrolink 91/Perris Valley & Inland Empire-Orange County lines (Corona) • State Route 71 (Corona Freeway) • Prado Dam • River Road (Norco/Eastvale) • Hamner Avenue (Norco) • Interstate 15 (Ontario Freeway) (Norco) • Van Buren Boulevard (Jurupa Valley) • Metrolink Riverside Line (Jurupa Valley/Riverside) • Mission Boulevard/Buena Vista Avenue (Jurupa Valley/Riverside) • State Route 60 (Pomona Freeway) (Jurupa Valley/Riverside) • Market Street (Jurupa Valley/Riverside) ===San Bernardino County=== • Riverside Avenue (Colton) • La Cadena Drive (Colton) • Metrolink Inland Empire-Orange County Line (Colton) • Railroad Bridge (Colton) • Mount Vernon Avenue (Colton) • Amtrak Sunset Limited & Texas Eagle (Colton) • Interstate 10 (San Bernardino/Redlands Freeway) (Colton) • Interstate 215 (San Bernardino/Riverside Freeway) (San Bernardino) • E Street (San Bernardino) • Waterman Avenue (San Bernardino) • Arrow commuter rail service (San Bernardino) • Orange Show Road (San Bernardino) • Tippecanoe Avenue (San Bernardino) • Alabama Street (Redlands) • State Route 210 (Foothill Freeway) (Redlands) • Orange Street (Redlands) • Greenspot Road (Highland) • Santa Ana Canyon Road • Seven Oaks Dam • State Route 38 ==See also==