Colorado River Delta as seen from space (2004)

The Colorado River Delta is the region of land where the Colorado River historically flowed into the Gulf of California, (the Sea of Cortez). The interaction of the river’s flow and the ocean’s tide created a dynamic environment, supporting freshwater, brackish, and saltwater species. Within the delta region, the river split into multiple braided channels and formed complex estuary and terrestrial ecosystems. Image File history File links Download high resolution version (1000x662, 381 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Colorado River Delta ... Image File history File links Download high resolution version (1000x662, 381 KB) Summary Licensing File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Colorado River Delta ... The Colorado River from the bottom of Marble Canyon, in the Upper Grand Canyon Colorado River in the Grand Canyon from Desert View The Colorado River is a river in the southwestern United States and northwestern Mexico, approximately 1,450 mi (2,330 km) long, draining a part of the... The Gulf of California (also known as the Sea of Cortez or Sea of Cortés; locally known in the Spanish language as Mar de Cortés or, much less frequently, Golfo de California) is a body of water that separates the Baja California Peninsula from the Mexican mainland. ... The Gulf of California (highlighted) The Gulf of California (also known as the Sea of Cortez or Sea of Cortés; locally known in the Spanish language as Mar de Cortés or, much less frequently, Golfo de California) is a body of water that separates the Baja California Peninsula... Brackish redirects here. ... Nile River delta, as seen from Earth orbit. ... Estuaries and coastal waters are among the most productive ecosystems on Earth, providing numerous ecological, economic, cultural, and aesthetic benefits and services. ...

Natural history

Until the early 20th century the Colorado River ran free from its headwaters in the Rocky Mountains of Colorado south into Mexico, where it flowed into the Gulf of California. Significant quantities of nourishing silt from throughout the Colorado River Basin were carried downstream, creating the vast Colorado River Delta. (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999 in the... White Goat Wilderness Area, Alberta, Canada Longs Peak of the Rocky Mountains as depicted on the Colorado state quarter The Rocky Mountains, often called the Rockies, are a broad mountain range in western North America. ... Official language(s) English Capital Denver Largest city Denver Area  - Total   - Width   - Length    - % water  - Latitude  - Longitude Ranked 8th 104,185 sq mi  269 837 km² 280 miles  451 km 380 miles  612 km 0. ...

Prior to the construction of major dams along its route, the Colorado River fed one of the largest desert estuaries in the world. Spread across the northernmost end of the Gulf of California, the Colorado River delta’s vast riparian, freshwater, brackish, and tidal wetlands once covered 1,930,000 acres (7,810 km²) and supported a large population of plant, bird, and marine life. Because most of the river’s flow reached the delta at that time, its freshwater, silt, and nutrients helped create and sustain a complex system of wetlands that provided feeding and nesting grounds for birds, and spawning habitat for fish and marine mammals. In contrast to the surrounding Sonoran Desert, the Colorado River delta’s abundance was striking. Scrivener Dam, in Canberra, Australia, was engineered to withstand a once-in-5000-years flood event A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment. ... Nile River delta, as seen from Earth orbit. ... A riparian zone schematic from the Everglades. ... A subtropical wetland in Florida, USA, with an endangered American Crocodile. ... Spawn is a comic book character. ... Sonoran Desert wildlife Mountains in the Sonoran Desert 3D photograph of Saguaro National Park at dusk. ...

Early explorers reported jaguars, beavers, deer, and coyotes in addition to the abundance of waterfowl, fish, and other marine and estuary organisms (Spamer, 1990; {Aldo Leopold, 1948}). Early explorers also encountered local people known as the Cucapá, or the people of the river. The Cucapá are descendants of the Yuman-speaking Native Americans and have inhabited the delta for nearly a thousand years. Spanish explorer Hernando de Alarcón made the first recorded contact with the Cucapá in 1540 and reported seeing many thousands. The Cucapá used the delta floodplain extensively, for harvesting Palmer’s saltgrass, a wild grain, and for cultivating maize (corn), beans, and squash. Binomial name Panthera onca (Linnaeus, 1758) The jaguar (Panthera onca) is a large member of the cat family found primarily in the warm regions of the Americas. ... Species C. canadensis C. fiber Beavers are semi-aquatic rodents native to North America and Europe. ... Subfamilies Capreolinae Cervinae Hydropotinae Muntiacinae A deer is a ruminant mammal belonging to the family Cervidae. ... Binomial name Canis latrans Say, 1823 The coyote (Canis latrans, meaning barking dog, also prairie wolf [2]) is a member of the Canidae (dog) family and a relative of the domestic dog. ... Falcated Duck at Slimbridge Wildfowl and Wetlands centre, Gloucestershire, England Wildfowl or waterfowl, also waterbirds, is the collective term for the approximately 147 species of swans, geese and ducks, classified in the order Anseriformes, family Anatidae. ... Orders See text. ... Aldo Leopold (January 11, 1887 - April 21, 1948) was a United States ecologist, forester, and environmentalist. ... Cocopa is a Native American tribe which emigated from Baja California and settled on the lower reaches of the Colorado River. ... The Yuman people are a group of Native American ethnic groups in the same language and cultural group as the Quechan (formerly known as Yuma). ... Hernando Ruiz de Alarcón, a Spanish navigator of the 16th century, noted for having led an early expedition to the peninsula of Baja California, meant to be coordinated with Francisco Vasquéz de Coronados overland expedition, and for penetrating the lower Colorado River, perhaps as far as the... Events January 6 - King Henry VIII of England marries Anne of Cleves, his fourth Queen consort. ... It has been suggested that this article or section be merged with Flood plain. ... #REDIRECT shoshanna[[sisainplants. ... This article is on the plant. ... Species - hubbard squash, buttercup squash - cushaw squash C. moschata- butternut squash C. pepo- most pumpkins, acorn squash, summer squash References: ITIS 223652002-11-06 Hortus Third Squashes are four species of the genus Cucurbita, also called pumpkins and marrows depending on variety or the nationality of the speaker. ...

On the map the Delta was bisected by the river, but in fact the river was nowhere and everywhere, for he could not decide which of a hundred green lagoons offered the most pleasant and least speedy path to the Gulf.

--Aldo Leopold, from A Sand County Almanac, describing the Colorado River Delta as it existed in 1922

Aldo Leopold (January 11, 1887 - April 21, 1948) was a United States ecologist, forester, and environmentalist. ...

After dam construction

Today, conditions in the delta have changed. Like other desert river deltas, such as the Nile Delta and the Indus River, the Colorado River delta has been greatly altered by human activity. Decades of dam construction and water diversions in the United States and Mexico have reduced the delta to a remnant system of small wetlands and brackish mudflats. As reservoirs filled behind dams and captured floodwaters, freshwater flows no longer reached the delta. NASA satellite photograph of the Nile Delta The Nile Delta is the delta formed in Northern Egypt where the Nile River spreads out and drains into the Mediterranean Sea. ... The Indus River in Northern Areas of Pakistan, near the rock Aornus. ... Scrivener Dam, in Canberra, Australia, was engineered to withstand a once-in-5000-years flood event A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment. ...

The construction of Hoover Dam in the 1930s marked the beginning of the modern era for the Colorado River Delta. For six years, as Lake Mead filled behind the dam, virtually no freshwater reached the delta. Even spring flooding was captured. This ecologically devastating event was repeated from 1963 to 1981 as Lake Powell filled behind the Glen Canyon Dam. With these reservoirs now filled, the dams are used to regulate flow so that water can be reliably apportioned among the users of the Colorado River Compact, and its use maximized. Most flood flows can be contained, regulated, and added to the river’s capacity to sustain the Western United States' urban centers and agriculture. Floodwaters are released only when the Bureau of Reclamation, the agency managing the dams, predicts flows that exceed the system’s capacity for use and storage. Hoover Dam Downstream from Hoover Dam, showing the river, power stations, and power lines. ... Lake Mead from space, November 1985 Lake Mead is the largest man-made lake and reservoir in the United States. ... Lake Powell is a man-made reservoir on the Colorado River, straddling the border between Utah and Arizona. ... Glen Canyon Dam on 19 June 2005. ... The Colorado River Compact is a 1922 agreement among seven U.S. states in the basin of the Colorado River in the American Southwest governing the allocation of the rivers water among the parties of the interstate compact. ... If you have been redirected here after viewing any statistical information, note that as defined by the Census Bureau, the western United States includes 13 states: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, and Wyoming. ... The United States Bureau of Reclamation (Formerly the United States Reclamation Service) is a division of the U.S. Department of the Interior which oversees water development projects in the western United States. ...

Colorado has done nothing to cause any devestation. There are many skeptics, however they are stupid and don't matter. Damming done in Colorado is for the good of the great citizens there. Little Doug is the biggest idiot ever. The loss of freshwater flows to the delta over the twentieth century has reduced delta wetlands to about 5 % of their original extent, and nonnative species have compromised the ecological health of much of what remains. Stress on ecosystems has allowed invasive plants to out compete native species along Colorado River riparian areas. Native forests of cottonwood and willow have yielded to sand and mudflats dominated by the nonnative tamarisk (also known as salt cedar), arrowweed, and iodinebush, a transformation that has decreased the habitat value of the riparian forest (Briggs and Cornelius, 1997). Invasive plants are defined by their ability to invade and disrupt an ecosystem. ... Species Populus deltoides L. Populus fremontii [[]] Populus nigra L. The cottonwoods are three species of poplars in the section Aegiros of the genus Populus, native to North America, Europe and western Asia. ... Species About 350, including: Salix acutifolia- Violet Willow Salix alaxensis- Alaska Willow Salix alba- White Willow Salix alpina- Alpine Willow Salix amygdaloides- Peachleaf Willow Salix arbuscula- Mountain Willow Salix arbusculoides- Littletree Willow Salix arctica- Arctic Willow Salix atrocinerea Salix aurita- Eared Willow Salix babylonica- Peking Willow Salix barrattiana- Barratts... Species See text The genus Tamarix (tamarisk) comprises about 50-60 species of flowering plants in the family Tamaricaceae, native to drier areas of Eurasia and Africa. ...

High flows throughout the 1980s

Full reservoir conditions coupled with a series of flood events throughout the 1980s and early 1990s resulted in flood releases that reached the delta. These flows reestablished an active floodplain and revegetated many areas of the floodplain within irrigation and flood control levees, and helped to reestablish riparian forests. MacGyver - 1980s hero The 1980s decade refers to the years from 1980 to 1989, inclusive. ... The 1990s decade refers to the years from 1990 to 1999, inclusive. ...

Ecology

The delta supports a variety of wildlife, including several threatened and endangered species. Mexico’s Environmental Regulations on Endangered Species lists the following endangered species found in the terrestrial and aquatic regions of the delta (Diario Officiel, 1994):

• the desert pupfish, also listed as an endangered species in the U.S., the largest remaining population anywhere is in La Ciénega de Santa Clara
• the Yuma Clapper Rail, also listed as an endangered species in the U.S.
• the bobcat
• the vaquita porpoise, the world's smallest marine mammal, listed as a species of special concern by the U.S. Marine Mammal Commission. There are thought to be less than 250 vaquita left in the world.
• the totoaba, now virtually extinct, a steel-blue fish that grows up to seven feet (2 m) and 300 pounds (136 kg), and once supported a commercial fishery that closed in 1975 (Postel et al., n.d.).

Although not extensively studied, the delta’s significance for migratory birds is indisputable, as it is the principle freshwater marsh in the region. A total of 358 bird species have been documented in the Colorado River Delta and upper Gulf of California region. From these, two are listed as endangered, six as threatened, and sixteen are under special protection in Mexico. Two wintering species and five breeding species have been locally extirpated, including the Southwestern Willow Flycatcher, the Fulvous-whistling Duck, and the Sandhill Crane. Binomial name Rallus longirostris Boddaert, 1783 The Clapper Rail (Rallus longirostris) is a member of the rail family, Rallidae. ... Binomial name Lynx rufus (Schreber, 1777) The Bobcat (Lynx rufus, commonly misinterpreted as Felis rufus) is a small wild cat indigenous to North America. ... Binomial name Phocoena sinus Norris & McFarland, 1958 Vaquita range The Vaquita (Phocoena sinus) is a rare species of porpoise. ... // Long-distance land bird migration Many species of land migratory birds migrate very long distances, the most common pattern being for birds to breed in the temperate or arctic northern hemisphere and winter in warmer regions, often in the tropics or the temperate zones of the southern hemisphere. ... This article does not cite its references or sources. ...

Biosphere reserve

The Gulf of California lies within the jurisdictional boundaries of Mexico and its states of Baja California and Sonora. In 1974, the Mexican government designated portions of the upper Gulf and lower Colorado River Delta as a reserve zone. The Gulf of California (also known as the Sea of Cortez or Sea of Cortés; locally known in the Spanish language as Mar de Cortés or, much less frequently, Golfo de California) is a body of water that separates the Baja California Peninsula from the Mexican mainland. ... Wikipedia does not yet have an article with this exact name. ... Baja California is the northernmost state of Mexico. ... Sonora is a state in northwestern Mexico, bordering the states of Chihuahua to the east, Sinaloa to the south, and Baja California to the northwest. ...

The United Nations Educational, Scientific and Cultural Organisation (UNESCO) designated over 3 million acres (12,000 km²) of upper Gulf of California and the Colorado River Delta as a Biosphere Reserve in June 1993. Within this 3 million acres (12,000 km²), over 1 million acres (4,000 km²) nearest the Colorado River Delta are designated as the Reserve “core area”, with the remaining 2 million acres (8,000 km²) of open water and shoreline designated as a “buffer area”. UNESCO logo The United Nations Educational, Scientific and Cultural Organization, commonly known as UNESCO, is a specialized agency of the United Nations system established in 1946. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

UNESCO considers areas for designation as Biosphere Reserves only after the nation in which the site is located submits a nomination. Once designated, Biosphere Reserves remain under the sovereign jurisdiction of the countries where they are located. Federal Mexican governmental agencies with administrative authority over the Biosphere Reserve include the National Commission of Protected Natural Areas (CONANP) and the Secretary of the Environment, Natural Resources and Fisheries (SEMARNAP) .

In addition to designation as a Biosphere Reserve, 2500 km² (618,000 acres) within Colorado River Delta (Humedales del Delta del Río Colorado) are designated as a Ramsar Wetland under the U.N. Convention on Wetlands. Ramsar Wetlands are wetlands of international importance in terms of their ecology, botany, zoology, limnology or hydrology. The U.N. designation is considered following a nomination by the nation in which the site is located. . ... This article is about the United Nations, for other uses of UN see UN (disambiguation) Official languages English, French, Spanish, Russian, Chinese, Arabic Secretary-General Kofi Annan (since 1997) Established October 24, 1945 Member states 191 Headquarters New York City, NY, USA Official site http://www. ...

External links

• http://www.conanp.gob.mx/anp/consulta/subzoni230204.pdf - Map of the Biosphere Reserve (in español)
• http://www.environmentaldefense.org/documents/425_Delta.pdf - A Delta Once More: Restoring Riparian and Wetland Habitat in the Colorado River Delta
• http://www.gulfconference.org/proceedings.html - Gulf of California Conference Proceedings (Technical Conference)
• http://www.ibwc.state.gov/html/colorado_river.html International Boundary and Water Commission Site on Colorado River Operations
• http://www.ibwc.state.gov/Files/Minutes/Min306.pdf - IBWC Minute 306 (Conceptual Framework for U.S. - Mx Studies for Future Recommendations Concerning the Riparian and Estuarine Ecology of the Limitrophe Section of the Colorado River and its Associated Delta.)
• http://www.ibwc.state.gov/FAO/CRDS0901/EnglishSymposium.pdf Proceedings of IBWC Colorado River Delta Symposium