The Arroyo Simi ( Spanish for "Small Stream of Simi", sometimes also referred to as Simi Creek)Appleton, Bill (2009). ''Santa Susana''. Arcadia Publishing. Page 27. . is a westwards-running

creek A creek in North America and elsewhere, such as Australia, is a stream that is usually smaller than a river. In the British Isles it is a small tidal inlet. Creek may also refer to: People * Creek people, also known as Muscogee, Native Americans ...

, located in

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, United States, running from the city of Simi Valley and crosses the

valley A valley is an elongated low area often running between Hill, hills or Mountain, mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers ...

from east to west, before entering the city of

Moorpark Moorpark is a city in Ventura County in Southern California. Moorpark was founded in 1900. The town grew from just over 4,000 citizens in 1980 to over 25,000 by 1990. As of 2006, Moorpark was one of the fastest-growing cities in Ventura County.. ...

. It originates at Corriganville Park by the Santa Susana Pass, and streams westwards into Moorpark where it merges with Arroyo Las Posas by Hitch Road. It extends for through the Simi Valley, and leaves the city limits by Oak Park at the western end Simi Valley, and continues for seven miles in Moorpark. It is a tributary to the

Calleguas Creek Calleguas Creek (; Chumash: ''Kayïwïsh'', meaning "the head") is the terminus of a river system in Ventura County, California. It drains the Calleguas Creek Watershed, an area 30 miles long and 14 miles wide (343 square miles), which includes Sim ...

, which enters the Pacific Ocean by its

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

at Mugu Lagoon by Naval Air Station Point Mugu. Besides an

arroyo Arroyo often refers to: * Arroyo (creek), an intermittently dry creek Arroyo may also refer to: People * Arroyo (surname) Places United States ;California * Arroyo Burro Beach, a public beach park in Santa Barbara County, California * Arroyo ...

, it has been described as a channel, waterway, river, drain, wash, and stream. Arroyo Simi drains an area of 343 square miles in southern Ventura County. In its natural state, it is an

ephemeral Ephemerality (from the Greek word , meaning 'lasting only one day') is the concept of things being transitory, existing only briefly. Academically, the term ephemeral constitutionally describes a diverse assortment of things and experiences, fr ...

creek, which is only seasonally filled during winter time and periods of heavy rain. Today it is for the most part a concrete lined water drain that flows year round. Tributaries to the Arroyo Simi includes Alamos Canyon-, Sycamore-, Dry Canyon-, Tapo Canyon-,

Las Llajas Canyon Las Llajas (pronounced YAH huhs) Canyon within the Marr Ranch Parkland contains the 1920s residential subdivision called Marrland and the surrounding open space area administrated by the Rancho Simi Recreation and Park District (RSRPD) and is l ...

-, White Oak-, Runkle Canyon-, and Bus Canyon Creeks, as well as the Erringer Road- and North Simi Drains. Arroyo Simi Greenway is an ongoing construction project by the City of Simi Valley in order to increase the recreational use of its river parkways. The project includes new paved hiking- and biking trails along the Arroyo Simi, exhibit signs, sixteen new trail entries, and more. The area is administrated as the Arroyo Simi Bike Path by the Rancho Simi Recreation and Park District (RSRPD). It is home to native flora, fish, and avifauna. It is home to fish species such as the

brown bullhead The brown bullhead (''Ameiurus nebulosus'') is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (''Ameiurus melas'') and yellow bullhead (''Ame ...

, green sunfish, bluntnose minnow, and

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 ...

. It is an important habitat for various species of freshwater-nesting birds in the Simi Valley. Some of the species include the

great blue heron The great blue heron (''Ardea herodias'') is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North America and Central America, as well as the Caribbean and the Galápagos ...

white-faced ibis The white-faced ibis (''Plegadis chihi'') is a wading bird in the ibis family, Threskiornithidae. This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western United States south ...

black-crowned night heron The black-crowned night heron (''Nycticorax nycticorax''), or black-capped night heron, commonly shortened to just night heron in Eurasia, is a medium-sized heron found throughout a large part of the world, including parts of Europe, Asia, and N ...

green heron The green heron (''Butorides virescens'') is a small heron of North and Central America. ''Butorides'' is from Middle English ''butor'' "bittern" and Ancient Greek ''-oides'', "resembling", and ''virescens'' is Latin for "greenish". It was long c ...

black-necked stilt The black-necked stilt (''Himantopus mexicanus'') is a locally abundant shorebird of American wetlands and coastlines. It is found from the coastal areas of California through much of the interior western United States and along the Gulf of Mexic ...

great egret The great egret (''Ardea alba''), also known as the common egret, large egret, or (in the Old World) great white egret or great white heron is a large, widely distributed egret. The four subspecies are found in Asia, Africa, the Americas, and ...

snowy egret 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 ...

belted kingfisher The belted kingfisher (''Megaceryle alcyon'') is a large, conspicuous water kingfisher, native to North America. All kingfishers were formerly placed in one family, Alcedinidae, but recent research suggests that this should be divided into three ...

black phoebe The black phoebe (''Sayornis nigricans'') is a passerine bird in the tyrant-flycatcher family. It breeds from southwest Oregon and California south through Central and South America. It occurs year-round throughout most of its range and migrates ...

, killdeer,

common yellowthroat The common yellowthroat (''Geothlypis trichas'') is a New World warbler. In the U.S. Midwest, it is also known as the yellow bandit. It is an abundant breeder in North America, ranging from southern Canada to central Mexico. The genus name ''Geot ...

, greater yellowlegs, American coot, and

mallard The mallard () or wild duck (''Anas platyrhynchos'') is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa, and has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Arge ...

.(Pages 30–33).

References

{{reflist, 2 Rivers of Ventura County, California Geography of Simi Valley, California Moorpark, California Santa Susana Mountains Simi Hills Washes of California Rivers of Southern California