# Arroyo Valle

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River in California, United States

Arroyo Valle Arroyo De Los Taunamines Arroyo del Valle in Pleasanton, California Arroyo Valle watershed (Interactive map) Location Country United States State California Region Santa Clara County City Pleasanton, California Physical characteristics Source Confluence of San Antonio Creek and Arroyo Bayo • coordinates 37°23′08″N 121°34′21″W / 37.38556°N 121.57250°W / 37.38556; -121.57250[1] • elevation 1,808 ft (551 m) Mouth Confluence with Arroyo de la Laguna • coordinates 37°39′43″N 121°54′22″W / 37.66194°N 121.90611°W / 37.66194; -121.90611[1] • elevation 302 ft (92 m)[1] Basin size 430 km2 (170 sq mi) Basin features Progression Arroyo Valle > Arroyo de la Laguna > Alameda Creek > San Francisco Bay > Pacific Ocean Tributaries • left Pino Creek, Sycamore Creek (Santa Clara County), Trout Creek (Santa Clara County) • right Spring Canyon Creek, Sulphur Gulch, Colorado Creek, Dry Creek, Eylar Canyon Creek, Lang Canyon Creek

Detail

The arroyo in [Pleasanton](/source/Pleasanton%2C_California)

**Arroyo Valle** or **Arroyo Del Valle**[2] is a 36.4-mile-long (58.6 km)[3] westward-flowing [stream](/source/Stream) that begins in northeastern [Santa Clara County, California](/source/Santa_Clara_County%2C_California), and flows northwesterly into [Alameda County](/source/Alameda_County%2C_California) where it is dammed to form [Lake Del Valle](/source/Lake_Del_Valle). After that Arroyo Valle is a tributary to [Arroyo de la Laguna](/source/Arroyo_de_la_Laguna) which in turn flows into [Alameda Creek](/source/Alameda_Creek) and thence to [San Francisco Bay](/source/San_Francisco_Bay). In the past, the Arroyo Valle had a significant [steelhead](/source/Rainbow_trout) migration; however, degradation of the stream in the latter half of the 20th century has decimated this [anadromous](/source/Anadromous) fish population.[4]

## History

Arroyo Valle was also once known as **Arroyo De Los Taunamines** (Stream of the Taunamines), for the [Costanoan](/source/Costanoan) Taunamines people who lived there. In 1853 it was renamed Arroyo del Valle (Stream of the Valley).[5]

## Watershed and Course

The Arroyo Valle watershed drains 147 square miles (380 km2).[6] The upper reaches of Arroyo Valle stretch into northeastern [Santa Clara County](/source/Santa_Clara_County) where the mainstem is formed by the confluence of [San Antonio Creek](/source/San_Antonio_Creek_(Santa_Clara_County)) and [Arroyo Bayo](/source/Arroyo_Bayo).[7] San Antonio Creek's origin is on the western slope of 3,804 feet (1,159 m) [Mount Stakes](/source/Mount_Stakes), west of the Santa Clara-[Stanislaus County](/source/Stanislaus_County) border, about 32 miles (51 km) southeast of [Livermore](/source/Livermore%2C_California). San Antonio Creek traverses the [San Antonio Valley](/source/San_Antonio_Valley%2C_California) as it heads west to Arroyo Valle. Arroyo Bayo also has its origin on Mount Stakes southwestern slope and traverses Upper San Antonio Valley as it also heads west to Arroyo Valle.

Arroyo Valle is dammed by the Del Valle Dam, which forms the reservoir [Lake Del Valle](/source/Lake_Del_Valle) in southeastern [Alameda County](/source/Alameda_County).

Downstream from the reservoir, Arroyo Valle drains much of the southern portion of the city of [Livermore](/source/Livermore%2C_California), and it also flows through and drains a considerable fraction of the city of [Pleasanton](/source/Pleasanton%2C_California), both in the [Livermore Valley](/source/Livermore_Valley). The stream is a tributary to [Arroyo de la Laguna](/source/Arroyo_de_la_Laguna), which is in turn tributary to [Alameda Creek](/source/Alameda_Creek), which ultimately reaches San Francisco Bay at [Fremont, California](/source/Fremont%2C_California).

## Ecology

[Water quality](/source/Water_quality) measurements in Arroyo Valle in the Livermore Valley indicate a [pH](/source/PH) level of 7.0, or neutral with respect to [acidity](/source/Acid); [phosphate](/source/Phosphate) levels were not detectable.[8]

In the middle reaches of Arroyo Valle south of Livermore, there has been considerable historic [grazing](/source/Grazing) use. Depth to groundwater in this reach of the watershed typically ranges from 50 feet (15 m) to 100 feet (30 m) and flows to the west.[9] Subsequent to this reach, the Arroyo del Valle flows down the moderately sloping hills to enter [gravel](/source/Gravel) pits, where extraction (but not processing) has historically been conducted by [Lone Star Industries](/source/Lone_Star_Industries).

Historically, Arroyo Valle was connected to [Tulare Lake](/source/Tulare_Lake_(Alameda_County)), a lagoon in the Livermore-Amador Valley, and thus to the Alameda Creek watershed. There are historical records of [steelhead trout](/source/Steelhead_trout) (*Oncorhynchus mykiss*) in Arroyo Valle although now the Lake Del Valle Dam is an impassable barrier to spawning runs.[6]

## See also

- [List of watercourses in the San Francisco Bay Area](/source/List_of_watercourses_in_the_San_Francisco_Bay_Area)

- [Arroyo de la Laguna](/source/Arroyo_de_la_Laguna)

- [Alameda Creek](/source/Alameda_Creek)

## References

1. ^ [***a***](#cite_ref-gnis_1-0) [***b***](#cite_ref-gnis_1-1) [***c***](#cite_ref-gnis_1-2) ["Arroyo Valle"](https://edits.nationalmap.gov/apps/gaz-domestic/public/search/names/232367). *[Geographic Names Information System](/source/Geographic_Names_Information_System)*. [United States Geological Survey](/source/United_States_Geological_Survey), [United States Department of the Interior](/source/United_States_Department_of_the_Interior).

1. **[^](#cite_ref-2)** [U.S. Geological Survey Geographic Names Information System: Arroyo Valle](https://edits.nationalmap.gov/apps/gaz-domestic/public/search/names/255060)

1. **[^](#cite_ref-NHD_3-0)** U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. [The National Map](https://viewer.nationalmap.gov/viewer/) [Archived](https://web.archive.org/web/20120329155652/http://viewer.nationalmap.gov/viewer/) 2012-03-29 at the [Wayback Machine](/source/Wayback_Machine), accessed March 15, 2011

1. **[^](#cite_ref-4)** [Arroyo del Valle Creekwatch](http://pleasanton.k12.ca.us/avhsweb/thiel/creek/index.html) [Archived](https://web.archive.org/web/20160303180220/http://pleasanton.k12.ca.us/avhsweb/thiel/creek/index.html) March 3, 2016, at the [Wayback Machine](/source/Wayback_Machine)

1. **[^](#cite_ref-5)** Page Mosier & Dan Mosier (1986). [*Alameda County Place Names*](https://books.google.com/books?id=JRkSAQAAIAAJ). Fremont, California: Mines Road Books. p. 12. [ISBN](/source/ISBN_(identifier)) [978-1-889064-02-4](https://en.wikipedia.org/wiki/Special:BookSources/978-1-889064-02-4). Retrieved March 12, 2016.

1. ^ [***a***](#cite_ref-Trout_6-0) [***b***](#cite_ref-Trout_6-1) Charles H. Hanson; Janet Sowers; Allen Pastron (August 2004). [Evaluation of the Potential Historical and Current Occurrence of Steelhead within the Livermore-Amador Valley](https://www.alamedacreek.org/reports-educational/pdf/Zone%207%202004.pdf) (PDF) (Report). Alameda County Flood Control and Water Conservation District - Zone 7. Retrieved April 30, 2021.

1. **[^](#cite_ref-7)** ["Arroyo Bayo"](https://edits.nationalmap.gov/apps/gaz-domestic/public/search/names/218394). *[Geographic Names Information System](/source/Geographic_Names_Information_System)*. [United States Geological Survey](/source/United_States_Geological_Survey), [United States Department of the Interior](/source/United_States_Department_of_the_Interior).

1. **[^](#cite_ref-8)** [Water Quality Testing in Arroyo del Valle](http://www.pleasanton.k12.ca.us/amador/creek/projects/Bio99/JJM/exp.html) [Archived](https://web.archive.org/web/20050309101321/http://www.pleasanton.k12.ca.us/amador/creek/projects/Bio99/JJM/exp.html) March 9, 2005, at the [Wayback Machine](/source/Wayback_Machine)

1. **[^](#cite_ref-9)** *Environmental Site Assessment, Murdell Lane, Unincorporated Alameda County*, EMI Report 10202, September 29, 1989

## External links

- [Arroyo Valle northern watershed map](http://museumca.org/creeks/133B09-OMAValle.html) at Oakland Museum of California

- [Current conditions for Arroyo Valle](https://waterdata.usgs.gov/nwis/uv?site_no=11176500) at US Geological Survey; shows current and historical gage height, discharge rate, and temperature

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Adapted from the Wikipedia article [Arroyo Valle](https://en.wikipedia.org/wiki/Arroyo_Valle) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Arroyo_Valle?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.