Arroyo de la Laguna explained

Arroyo de la Laguna
Name Etymology:Spanish
Pushpin Map:USA California
Pushpin Map Size:300
Pushpin Map Caption:Location of the mouth of Arroyo de la Laguna in California
Subdivision Type1:Country
Subdivision Name1:United States
Subdivision Type2:State
Subdivision Name2:California
Subdivision Type3:Region
Subdivision Name3:Alameda County
Subdivision Type5:City
Subdivision Name5:Pleasanton
Source1:confluence
Source1 Location:Pleasanton
Source1 Coordinates:37.6767°N -121.9122°W
Source1 Elevation:315feet
Mouth:Alameda Creek
Mouth Location:south of Sunol, California
Mouth Coordinates:37.5883°N -121.8908°W
Mouth Elevation:217feet
Tributaries Left:Arroyo Valle
Tributaries Right:Sinbad Creek

Arroyo de la Laguna is a 7.5adj=midNaNadj=mid[1] southward-flowing stream in Alameda County, California, United States which originates at the confluences of South San Ramon Creek and Arroyo Mocho. The Arroyo de la Laguna is fed by tributaries in the Amador Valley and certain eastern slope drainages of the Diablo Range; these tributaries include Arroyo Valle and Sinbad Creek. Arroyo del la Laguna is the major tributary to Alameda Creek which in turn flows into the San Francisco Bay.

From prehistoric times much of the eastern part of the Amador Valley consisted of a lake known as Tulare Lake. With development of the valley starting in the 19th century, drainage alterations in this watershed reduced the lake to a watercourse now called the Arroyo de la Laguna.[2]

Hydrogeology

In the northern portion of the Arroyo de la Laguna catchment basin, the Tassajara Formation underlies Quaternary valley fill material.[3] Contacts of these two formations are often indistinguishable due to similarities of physical characteristics. The prism of sediments identified as valley fill materials contains from eight to ten separate zones of sand and gravel separated by zones of silt and clay.

Rapid development and other historic changes in the upper watershed have caused severe instability in the lower 5 miles of the Arroyo de la Laguna.[4]

See also

Notes and References

  1. U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map, accessed March 15, 2011
  2. http://www.museumca.org/creeks/133B03-OMALaguna.html Arroyo de la Laguna: Watershed Map and Profile
  3. C.Michael Hogan and Marc Papineau, Phase I Environmental Site Assessment, Vicinity of Deerwood Drive and Bollinger Canyon Road, San Ramon, California, Earthurl= Metrics Inc.File ref 7815, San Mateo, Ca. (1989)
  4. Web site: Arroyo de la Laguna Restoration Projects . Alameda County Resource Conservation District . 2017-01-06 .