Laguna Canyon , also called Cañada de las Lagunas ( Spanish for 'Canyon of the Lakes'), is a gorge that cuts through the San Joaquin Hills in southern Orange County , California , in the United States , directly south of the city of Irvine . The canyon runs from northeast to southwest, and is drained on the north side by tributaries of San Diego Creek and on the south by Laguna Canyon Creek. It is deeper and more rugged on the southwestern end near Laguna Beach .
41-485: Geologically, the canyon likely originated millions of years ago as the result of San Diego Creek cutting through the San Joaquin Hills. Uplift diverted that stream to its present course, leaving Laguna Canyon as a wind gap . California State Route 133 runs the entire length of the canyon connecting Laguna Beach and Irvine, while California State Route 73 crosses it, running southeast–northwest. A majority of
82-479: A riprap channel with an unlined bottom, which transitions to a concrete culvert. These improvements help to protect infrastructure in the canyon from storm and landslide damage. There is little development within the main canyon, although the El Toro Creek area is primarily residential . There is also some residential and commercial development downstream of State Route 73. The concrete channel in this area
123-415: A stub . You can help Misplaced Pages by expanding it . Flash flood A flash flood is a rapid flooding of low-lying areas: washes , rivers , dry lakes and depressions . It may be caused by heavy rain associated with a severe thunderstorm , hurricane , or tropical storm , or by meltwater from ice and snow . Flash floods may also occur after the collapse of a natural ice or debris dam , or
164-512: A 100-foot (30 m) waterfall) and larger Willow Canyon join from the right, then about 0.5 miles (0.80 km) later, the creek re-emerges from underground and flows in a riprap lined channel for the next few miles. It receives its major tributary, El Toro Creek, from the left. El Toro Creek, which follows El Toro Road for much of its length, drains parts of Laguna Hills and Aliso Viejo before emptying into Laguna Canyon Creek. The creek turns sharply west and then back south, then shortly after,
205-717: A human structure such as a man-made dam , as occurred before the Johnstown Flood of 1889. Flash floods are distinguished from regular floods by having a timescale of fewer than six hours between rainfall and the onset of flooding. Flash floods are a significant hazard, causing more fatalities in the U.S. in an average year than lightning, tornadoes , or hurricanes . They can also deposit large quantities of sediments on floodplains and destroy vegetation cover not adapted to frequent flood conditions. Flash floods most often occur in dry areas that have recently received precipitation , but they may be seen anywhere downstream from
246-399: A minor fault zone, stayed year round. A Native American path ran through the canyon to the present-day Laguna Beach area, where they fished and collected abalone and limpets . The Tongva lived in villages of 50-100 people, in huts made of brushes and tules on a wooden framework. When Spanish explorers arrived in the mid-18th century, they named the canyon "Cañada de las Lagunas", referring to
287-427: A storm that occurs on a mesa miles away. The flood sweeps through the canyon; the canyon makes it difficult to climb up and out of the way to avoid the flood. For example, a cloudburst in southern Utah on 14 September 2015 resulted in 20 flash flood fatalities, of which seven fatalities occurred at Zion National Park when hikers were trapped by floodwaters in a slot canyon. Flash floods induce severe impacts in both
328-447: A very short time. Second, these rains often fall on poorly absorbent and often clay-like soil, which greatly increases the amount of runoff that rivers and other water channels have to handle. These regions tend not to have the infrastructure that wetter regions have to divert water from structures and roads, such as storm drains, culverts, and retention basins , either because of sparse population or poverty, or because residents believe
369-555: Is a gap through which a waterway once flowed that is now dry as a result of stream capture . A water gap is a similar feature, but one in which a waterway still flows. Water gaps and wind gaps often provide routes which, due to their gently inclined profile, are suitable for trails , roads , and railroads through mountainous terrain. Examples of wind gaps in the Blue Ridge Mountains of Virginia include Swift Run Gap , Rockfish Gap , and Buford's Gap . The last
410-602: Is augmented by donations of vacant land. The proposal to stop the development was supported by a crowd of eight to eleven thousand on November 11, 1989. This large group gathered in downtown Laguna Beach and marched out to the photographic mural "The Tell", created by the Laguna Canyon Project , in the Sycamore Hills area of Laguna Canyon. This protest was called the "Walk to Save Laguna Canyon". Several years later, two to three thousand gathered to protest
451-432: Is enough to carry away most SUV-sized vehicles. The U.S. National Weather Service reported in 2005 that, using a national 30-year average, more people die yearly in floods, 127 on average, than by lightning (73), tornadoes (65), or hurricanes (16). In deserts , flash floods can be particularly deadly for several reasons. First, storms in arid regions are infrequent, but they can deliver an enormous amount of water in
SECTION 10
#1732798668610492-515: Is forced into a concrete-lined box culvert that carries it through downtown Laguna Beach (This stretch is also known as Broadway Creek.) It then is diverted completely underground and its channel winds to an outfall at Main Beach, one of the most popular beaches in Laguna Beach. Laguna Canyon and its side tributaries have received some flood control modifications. These include debris basins at
533-462: Is no trail that follows the main canyon (as it is traversed by State Route 133), there are many trails, mostly hiking, that lead up narrow side canyons, as well as a trail that circumnavigates Laguna Lakes. Several connecting trails run east-south towards Aliso and Wood Canyons, providing access between the two watersheds. Lying to the north of Aliso Canyon , the Laguna Canyon area lay within
574-468: Is one of the last remaining sanctuaries for many plants native to Southern California. Approximately one hundred species of plants, most native to California, are found in Laurel and Willow Canyons alone. These include monkey flower , goldenrod , and sagebrush . Laguna Canyon forms the center section of an approximately 17,500-acre (71 km) strip of wilderness preserve running northeast–southwest along
615-465: Is one of the last remaining wild areas in Orange County in a strip of preserves along the San Joaquin Hills about 20 miles (32 km) long and 8 miles (13 km) wide. Recently, State Route 133 between the 405 and 73 freeways has been expanded to four lanes from the original two lanes, and much of the original road down the center of the canyon has been demolished and re-vegetated. The new road
656-531: Is part of the Laguna Coast Wilderness Park, while the upper section also has a few smaller wilderness preserves. The upper section contains Barbara's Lake which is Orange County's only natural lake formed by groundwater rising along a local fault line . This and two smaller intermittent ponds are the namesake of the canyon. A section of the lower canyon within the city limits of Laguna Beach is heavily developed. The northernmost extreme of
697-512: Is small and undersized for major floods, which caused it to overflow in the late 1990s and again in 2010. The Laguna Canyon area supports a variety of native Southern California wildlife, including large mammals such as mountain lions , bobcats , coyotes and mule deer . Like Aliso and Wood Canyons Regional Park to the south, the canyon supports over one hundred species of birds. Some of its endangered species include California gnatcatcher , cactus wren , and orange-throated whiptail . Except for
738-658: The Laguna College of Art and Design , the Sawdust Art Festival venues and other establishments. Most of the remaining wild areas are now found in the side canyons. Urban runoff has resulted in bacterial pollution downstream at Main Beach in Laguna Beach. Several organizations are now dedicated to preserving the remaining wild areas of the canyon, including the Laguna Canyon Foundation. Wind gap A wind gap (or air gap )
779-649: The Pacific coast . Most of the canyon is covered Laguna Coast Wilderness Park , which is 7,000 acres (28 km). It is bordered on the south by Aliso and Wood Canyons Regional Park, and on its north by Crystal Cove State Park . The parks are managed by the County of Orange and the California Department of Fish and Game , while portions of Laguna Coast are also owned by the City of Laguna Beach. Although there
820-546: The Laguna Lakes, the canyon has no fish habitat, and riparian habitat is sparse because the local creeks have only seasonal flow. The dominant vegetation cover of coastal sage scrub typically goes through approximately 25-year cycles, with its peak biodiversity reached in roughly 10 years after the beginning of a new 25-year period. Such periods are typically separated by wildfires , which clear away dead or dying vegetation and leave bare ground for new growth. The canyon
861-399: The Laguna Lakes. A land grant called La Bolsa de San Joaquín occupied the canyon area up to the 19th century. By 1905, Laguna Beach began to draw municipal water from springs in Laguna Canyon. Before Laguna Canyon became a wilderness park, a housing development was proposed to be built in and around the canyon, tentatively called "Laguna Laurel". The 2,150-acre (8.7 km) community, which
SECTION 20
#1732798668610902-492: The San Diego Creek watershed is very small, allowing for the canyon's modern use as a transportation route. Laguna Canyon Creek begins as an ephemeral creek draining a mountainside west of the valley floor down into the canyon. It is briefly culverted where it crosses under Laguna Canyon Road, but most of the upper course flows in a natural channel. It soon passes the Laguna Lakes and receives Little Sycamore Canyon from
943-479: The U.S. National Weather Service (NWS) Storm Data datasets to connect the impact of flash floods with the physical processes involved in flash flooding. This should increase the reliability of flash flood impact forecasting models. Analysis of flash floods in the United States between 2006 and 2012 shows that injuries and fatalities are most likely in small, rural catchments, that the shortest events are also
984-479: The built and the natural environment. The effects of flash floods can be catastrophic and show extensive diversity, ranging from damages in buildings and infrastructure to impacts on vegetation, human lives and livestock. The effects are particularly difficult to characterize in urban areas. Researchers have used datasets such as the Severe Hazards Analysis and Verification Experiment (SHAVE) and
1025-486: The canyon is located within the Laguna Coast Wilderness Park ; small portions are part of Aliso and Wood Canyons Wilderness Park and the cities of Irvine, Laguna Beach, Laguna Woods and Aliso Viejo . Laguna Canyon is approximately 8 miles (13 km) long and 1 mile (1.6 km) wide at the widest points. The city of Irvine lies to the northeast, Lake Forest and Aliso Viejo to the east,
1066-477: The canyon lies near a residential area that adjoins Interstate 405 . The canyon was most likely formed by San Diego Creek cutting through the rising San Joaquin Hills over a span of about 1.22 million years. At some point, however, the creek changed course, and the water gap it had formed was walled off by the mountains and became a separate watershed. The gradient of the drainage divide separating Laguna Canyon and
1107-456: The construction of California State Route 73 (which would cross the canyon), but the highway was built eventually. In 1993, a massive wildfire burned over 16,000 acres (65 km) in Laguna Canyon and Laguna Beach, and ranked behind the 1948 Santa Ana Canyon fire as one of the worst fires in Orange County history. The fire was in part caused by strong Santa Ana Winds , which caused flames that rose up to 200 feet (61 m) high. The canyon
1148-439: The dangers of flash floods. What makes flash floods most dangerous is their sudden nature and fast-moving water. A vehicle provides little to no protection against being swept away; it may make people overconfident and less likely to avoid the flash flood. More than half of the fatalities attributed to flash floods are people swept away in vehicles when trying to cross flooded intersections. As little as 2 feet (0.61 m) of water
1189-432: The flood effects are grouped into 4 categories: (i) impacts on built environment (ii) impacts on man-made mobile objects,(iii) impacts on the natural environment (including vegetation, agriculture, geomorphology, and pollution) and (iv) impacts on the human population (entrapments, injuries, fatalities). The scale was proposed as a tool on prevention planning, as the resulting maps offer insights on future impacts, highlighting
1230-643: The high severity areas. Flash floods can cause rapid soil erosion. Much of the Nile delta sedimentation may come from flash flooding in the desert areas that drain into the Nile River . However, flash floods of short duration produce relatively little bedrock erosion or channel widening, having their greatest impact from sedimentation on the floodplain. Some wetlands plants, such as certain varieties of rice, are adapted to endure flash flooding. However, plants that thrive in drier areas can be harmed by flooding, as
1271-414: The most dangerous, that the hazards are greatest after nightfall, and that a very high fraction of injuries and fatalities involve vehicles. An impact severity scale is proposed in 2020 providing a coherent overview of the flash flood effects through the classification of impact types and severity and mapping their spatial extent in a continuous way across the floodplain. Depending on the affected elements,
Laguna Canyon - Misplaced Pages Continue
1312-504: The mouth of nearly every major tributary, stretches of lined or unlined flood control channels , and other structures. The debris basins, sometimes called retention basins , are circular depressions constructed by the Orange County Flood Control Division to slow down flash floods . The upper Laguna Canyon area has a few flood control channels and the lower creek is encased entirely in one; this begins as
1353-512: The right; this creek drains a narrow side canyon which runs about 2 miles (3.2 km) eastward. The creek continues southward, and then passes beneath Laguna Canyon Rd. again and receives Camarillo Canyon, a short and steep tributary, from the right. The stream then runs south under the twin California State Route 73 bridges and enters an underground culvert beneath an onramp. While in this culvert, Laurel Canyon (which harbors
1394-567: The risk of flash floods is not high enough to justify the expense. In fact, in some areas, desert roads frequently cross a dry river and creek beds without bridges. From the driver's perspective, there may be clear weather, when a river unexpectedly forms ahead of or around the vehicle in a matter of seconds. Finally, the lack of regular rain to clear water channels may cause flash floods in deserts to be headed by large amounts of debris, such as rocks, branches, and logs. Deep slot canyons can be especially dangerous to hikers as they may be flooded by
1435-624: The source of the precipitation, even many miles from the source. In areas on or near volcanoes , flash floods have also occurred after eruptions, when glaciers have been melted by the intense heat. Flash floods are known to occur in the highest mountain ranges of the United States and are also common in the arid plains of the Southwestern United States. Flash flooding can also be caused by extensive rainfall released by hurricanes and other tropical storms , as well as
1476-442: The sudden thawing effect of ice dams . Human activities can also cause flash floods to occur. When dams fail , a large quantity of water can be released and destroy everything in its path. The United States National Weather Service gives the advice "Turn Around, Don't Drown" for flash floods; that is, it recommends that people get out of the area of a flash flood, rather than trying to cross it. Many people tend to underestimate
1517-652: The tribal boundary of the Tongva , a Native American group whose territory expanded from north-central Orange County well past the San Gabriel River and into the Los Angeles Basin . Aliso Creek , whose watershed borders Laguna Canyon to the east, formed the tribal boundary between the Tongva and Acjachemen . Laguna Canyon Creek was a seasonal stream but the Laguna Lakes, formed by springs arising from
1558-408: The undeveloped San Joaquin Hills to the west, and Laguna Beach to the south. The drainage divide of the canyon near its northern end separates Laguna Canyon Creek from the San Diego Creek watershed. State Route 133, locally called Laguna Canyon Road, winds through Laguna Canyon for the entire length of the gorge. California State Route 73 bisects the gorge east–west. The lower section of the canyon
1599-423: Was constructed further from the creek bed to lessen environmental impacts. The northernmost extreme of the canyon is being developed into a residential area consisting of 590 homes, called Laguna Crossing, the first phase of which was opened in 2013. Other parts of Laguna Canyon have been impacted by development. The last 3 miles (4.8 km) of the canyon, closest to downtown Laguna Beach, are urbanized, containing
1640-402: Was proposed to contain 3,200 housing units as well as a number of businesses, was canceled in the 1990s after the City of Laguna Beach purchased four of its parcels in order to provide space for a wilderness park, while the City of Irvine purchased one, and Laguna Coast Wilderness Park was opened and dedicated in 1993. Occasionally, the park system (which adjoins Aliso/Wood Canyons Regional Park )
1681-645: Was the original crossing of the Blue Ridge Mountains near Bedford for the Virginia and Tennessee Railroad , later the Norfolk and Western Railway , a precursor of today's Norfolk Southern Railway system. Another wind gap with substantial importance in U.S. history is the Cumberland Gap near the junction of Kentucky, Virginia, and Tennessee. This article about geography terminology is