Arroyo Mocho is a 34.7 miles (55.8 km) stream in eastern Alameda County, California

Alameda County, California

Alameda County is a county in the U.S. state of California. It occupies most of the East Bay region of the San Francisco Bay Area. As of the 2010 census it had a population of 1,510,271, making it the 7th most populous county in the state...

 that traverses the cities of Livermore

Livermore, California

Livermore is a city in Alameda County. The population as of 2010 was 80,968. Livermore is located on the eastern edge of California's San Francisco Bay Area....

 and Pleasanton

Pleasanton, California

Pleasanton is a city in Alameda County, California, incorporated in 1894. It is a suburb in the San Francisco Bay Area located about east of Oakland, and west of Livermore. The population was 70,285 at the 2010 census. In 2005 and 2007, Pleasanton was ranked the wealthiest middle-sized city in...

.

The underlying aquifer is the Mocho Subbasin

Mocho Subbasin

The Mocho Subbasin is the largest of the groundwater subbasins in the Livermore Valley watershed. This subbasin is bounded to the west by the Livermore Fault Zone and to the east by the Tesla Fault...

, whose eastern boundary is the Tesla Fault

Tesla Fault

The Tesla Fault is a seismically active geological fault structure associated with the Diablo Range in the vicinity of the Livermore Valley in Contra Costa County, California.-Geology:...

. Some groundwater flow occurs across this fault boundary, but flows are discontinuous below a depth of 50 feet (15.2 m) across the Tesla Fault and south of the Arroyo Mocho channel across the Livermore Fault.

See also

• Arroyo del Valle
  Arroyo del Valle
  Arroyo del Valle or Arroyo Valle is a westward-flowing stream in Alameda County and Santa Clara County, California, USA, that is tributary to Arroyo de la Laguna which in turn flows into Alameda Creek. The stream drains much of the southern portion of the city of Livermore, and it also flows...
  
  
• Hacienda Business Park
  Hacienda Business Park
  Hacienda Business Park is a 900 acre mixed used job center and housing development in Pleasanton, California.-History:Approved in 1982 and ratified by Pleasanton voters in 1983, the business park covers approximately 20 square blocks and features many multi-story office buildings and headquarters...
  
  
• List of watercourses in the San Francisco Bay Area