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 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 metropolitan area is home to 1,000, ...

, 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 watershed that encompasses parts of seven U.S. s ...

. 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 Hol ...

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 togeth ...

, 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, 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 C ...

; during those times, the Rio Hardy served as an overflow channel 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 to the west and the southern slope of Cerro Prieto. 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 Hardy's wetlands are a nesting ground for the snowy egrets (Egretta thula), and with the bird habitat, 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 ...

, 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