The Hardy River ( es, Río Hardy) is a -long

Mexican Mexican may refer to: Mexico and its culture *Being related to, from, or connected to the country of Mexico, in North America ** People *** Mexicans, inhabitants of the country Mexico and their descendants *** Mexica, ancient indigenous people ...

river formed by residual agricultural waters from the

Mexicali Valley Mexicali (; ) is the capital city of the States of Mexico, Mexican state of Baja California. The city, seat of the Mexicali Municipality, has a population of 689,775, according to the 2010 census, while the Calexico–Mexicali, Calexico–Mexical ...

, and running into the

Colorado River The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid drainage basin, watershed that encompasses parts of ...

. The river is believed to have been an ancient channel of the Colorado, as well as the primary outflow for the prehistoric

Lake Cahuilla Lake Cahuilla ( ; also known as Lake LeConte and Blake Sea) was a prehistoric lake in California and northern Mexico. Located in the Coachella and Imperial valleys, it covered surface areas of to a height of above sea level during the Holocen ...

History

In prehistoric times, during the

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

, the Colorado River periodically flowed north into the

Salton Sink The Salton Sink is the low point of an endorheic basin, a closed drainage system with no outflows to other bodies of water, in the Colorado Desert sub-region of the Sonoran Desert. The sink falls within the larger Salton Trough and separates the ...

, forming a large lake called

. Eventually, this lake would fill, to about 30 feet above sea level, and at that point overflow its banks near

Cerro Prieto Cerro Prieto ( coc, Wee Ñaay, eng, "Black Hill") is a volcano located approximately 29 km (18 mi) SSE of Mexicali in the Mexican state of Baja California. The volcano lies astride a spreading center associated with the East Pacific R ...

, and run south to the

Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja Ca ...

; during those times, the Rio Hardy served as an

overflow channel Overflow may refer to: Computing and telecommunications *Integer overflow, a condition that occurs when an integer calculation produces a result that is greater than what a given register can store or represent *Buffer overflow, a situation whereb ...

for Lake Cahuilla. In the 19th century, an English lieutenant, R. W. H. Hardy, explored the Colorado River Delta, and noted that the main channel of the Colorado followed this course. Later, in the 1880s, sea captains noted that the main channel of the Colorado had moved east; this earlier channel became known as Hardy's Colorado.

Hydrology

The watershed of the Hardy River includes runoff from the eastern foothills of

Sierra de Los Cucapah Sierra de Los Cucapah is a mountain range in Baja California state, Northwestern Mexico. It is located south of Mexicali. The range is named after the Cocopah who arrived in the area around 700 b.c and still live in the area. The Sierra de los Cu ...

to the west and the southern slope of

. Due the dynamic course of the Colorado River within Mexicali Valley, the Hardy River may have periodically become the primary watercourse of the Colorado as it flowed south to the

Wildlife

The Rio Hardy is home to a variety of wildlife, including the

mosquitofish The western Mosquitofish (''Gambusia affinis'') is a North American freshwater fish, also known commonly, if ambiguously, as simply Mosquitofish or by its generic name, ''Gambusia'', or by the common name gambezi. Its sister species, the easte ...

and the

sailfin molly The sailfin molly (''Poecilia latipinna'') is a species of fish of the genus ''Poecilia''. They inhabit fresh, brackish, salt, and coastal waters from North Carolina to Texas and the Yucatán Peninsula of Mexico. Taxonomy The sailfin molly was o ...

The Hardy's wetlands are a

nesting ground In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

for the

snowy egrets The snowy egret (''Egretta thula'') is a small white heron. The genus name comes from Provençal French for the little egret, , which is a diminutive of , 'heron'. The species name ''thula'' is the Araucano term for the black-necked swan, app ...

(Egretta thula), and with the

bird habitat Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

, are part of a protected Mexican

biosphere reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or o ...

, the '' Reserva de la Biosfera del Alto Golfo de California y Delta del Rio Colorado''.

Water quality

In recent years, the Hardy has become a drain for agricultural waters polluted with pesticides and fertilizers from the Mexicali Valley. The water quality in the Hardy is being monitored at Mexicali by the ''Centro de Investigacion en Alimentacion y Desarrollo A.C.'' (Food and Development Research Center) to measure the effects of discharge from the Las Arenitas wastewater treatment plant.http://www.epa.gov/border2012/regional/workgroup-ca.html

Sources

The State of Baja California: Hydrology

* ttp://www.epa.gov/border2012/regional/workgroup-ca.html E.P.A.: California-Baja California Regional Workgroup: California-Baja California Water
Río Hardy: A tribe without a river, by Celia Rosario Rivas and Luis Carlos Romero-Davis, Tucson Citizen, June 20, 2006

Contaminants in Potential Prey of the Yuma Clapper Rail, U.S. Fish and Wildlife Service

References

{{Colorado River system Tributaries of the Colorado River Rivers of Baja California