Arroyo Valle or Arroyo Del Valle is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data
The National Map
, accessed March 15, 2011 westward-flowing

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...

that begins in northeastern

Santa Clara County, California Santa Clara County, officially the County of Santa Clara, is the sixth-most populous county in the U.S. state of California, with a population of 1,936,259, as of the 2020 United States Census, 2020 census. Santa Clara County and neighboring Sa ...

, and flows northwesterly into

Alameda County Alameda County ( ) is a List of counties in California, county located in the U.S. state of California. As of the 2020 United States Census, 2020 census, the population was 1,682,353, making it the 7th-most populous county in the state and List ...

where it is dammed to form

Lake Del Valle Lake Del Valle is a storage reservoir located southeast of Livermore, in Alameda County, California. It is within Del Valle Regional Park. Lake description It is on Arroyo Valle (Spanish for "creek of the valley") in the Diablo Range. The lake ...

. After that Arroyo Valle is tributary to Arroyo de la Laguna which in turn flows into Alameda Creek and thence to

San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from a ...

. In the past, the Arroyo Valle had a significant

steelhead Steelhead, or occasionally steelhead trout, is the common name of the anadromous form of the coastal rainbow trout or redband trout (O. m. gairdneri). Steelhead are native to cold-water tributaries of the Pacific basin in Northeast Asia and N ...

migration; however, degradation of the stream in the latter half of the 20th century has decimated this

anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

fish population.

History

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

Watershed and Course

The Arroyo Valle watershed drains . The upper reaches of Arroyo Valle stretch into northeastern

Santa Clara County Santa Clara County, officially the County of Santa Clara, is the sixth-most populous county in the U.S. state of California, with a population of 1,936,259, as of the 2020 United States Census, 2020 census. Santa Clara County and neighboring Sa ...

where the mainstem is formed by the confluence of San Antonio Creek and Arroyo Bayo. San Antonio Creek's origin is on the western slope of

Mount Stakes Mount Stakes is a mountain in the Diablo Range in California. The peak is located on the Santa Clara– Stanislaus county line and is located less than 1 mile north of Henry W. Coe State Park. It rises to an elevation of and is the highest poin ...

, west of the Santa Clara-

Stanislaus County , image_skyline = , image_caption = Images, from top down, left to right: Modesto Arch, Knights Ferry's General Store, a view of the Tuolumne River from Waterford , image_flag = , i ...

border, about southeast of Livermore. San Antonio Creek traverses the

San Antonio Valley The community of San Antonio Valley, also called San Antonio or San Antone, is located along the Diablo Range in eastern Santa Clara County, California. The locale is bordered by Alameda County to the north and Stanislaus County to the east. ...

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

in southeastern

. Downstream from the reservoir, Arroyo Valle drains much of the southern portion of the city of Livermore, and it also flows through and drains a considerable fraction of the city of Pleasanton, both in the

Livermore Valley The Livermore Valley, historically known as the Valle de San José (Valley of San José), is a valley in Alameda County, California, located in the East Bay region. The city of Livermore is located in the valley. Geography The valley is bound ...

. The stream is tributary to Arroyo de la Laguna, which is in turn tributary to Alameda Creek, which ultimately reaches San Francisco Bay at

Fremont, California Fremont is a city in Alameda County, California, United States. Located in the East Bay region of the San Francisco Bay Area, Bay Area, Fremont has a population of 230,504 as of 2020, making it the fourth List of cities and towns in the San Fra ...

Ecology

Water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

measurements in Arroyo Valle in the Livermore Valley indicate a pH level of 7.0, or neutral with respect to

acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...

ity;

phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phospho ...

levels were not detectable. In the middle reaches of Arroyo Valle south of Livermore, there has been considerable historic

grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other ...

use. Depth to groundwater in this reach of the watershed typically ranges from to and flows to the west.''Environmental Site Assessment, Murdell Lane, Unincorporated Alameda County'', EMI Report 10202, September 29, 1989 Subsequent to this reach, the Arroyo del Valle flows down the moderately sloping hills to enter

gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

pits, where extraction (but not processing) has historically been conducted by Lone Star Industries. Historically, Arroyo Valle was connected to Tulare Lake, a lagoon in the Livermore-Amador Valley, and thus to the Alameda Creek watershed. There are historical records of

steelhead trout Steelhead, or occasionally steelhead trout, is the common name of the anadromous form of the coastal rainbow trout or redband trout (O. m. gairdneri). Steelhead are native to cold-water tributaries of the Pacific basin in Northeast Asia and N ...

(''Oncorhynchus mykiss'') in Arroyo Valle although now the Lake Del Valle Dam is an impassable barrier to spawning runs.

References

{{reflist

External links

Arroyo Valle northern watershed map
at Oakland Museum of California
Current conditions for Arroyo Valle
at US Geological Survey; shows current and historical gage height, discharge rate, and temperature Rivers of Alameda County, California Rivers of Santa Clara County, California Tributaries of Alameda Creek Diablo Range Livermore Valley Livermore, California Geography of Pleasanton, California Rivers of Northern California

History

Watershed and Course

Ecology

See also

References

External links