San Diego Hydrogeology


Santa Ysabel - SDSY (12S/1W-34L2-5)

Lithologic Summary

Land-surface elevation is 402.23 feet above NAVD88. Depth is in feet below land surface. Drilled by U.S. Geological Survey using hydraulic rotary, October 23, 2010. Total depth drilled 355 feet. Screened intervals: 280-340, 190-210, and 70-90 feet.

Depth (ft) Description
From To
0 19 Sand (f-vc) w/ minor gravel (peb); Lt olive brown (2.5Y 5/6)
19 30 Silty Clay; V. dark grayish brown (2.5Y 3/2)
30 66 Sand (f-vc) w/ minor gravel (peb); Grayish green (GLEY2 5/10G)
66 75 Silty Sand (f-c) w/ minor clay; V dark grey (2.5Y 3/1)
75 83 Silty Clay; Brown (10YR 4/3)
83 87 Sand (m-vc) w/ gravel (peb); Grayish green (GLEY2 5/10G)
87 100 Clayey Silt; Brown (10YR 5/4)
100 120 Clayey Silty Sand (f-vc); Yellowish Brown (10YR 5/4)
120 230 Weathered bedrock; Biotite Hornblend Granodiorite; Salt & Pepper
230 355 Bedrock; Biotite Hornblend Granodiorite; Salt & Pepper

Project Chief: Wes Danskin
Phone: 619-225-6132
Email: wdanskin@usgs.gov


Welcome to the United States Geological Survey (USGS) San Diego Hydrogeology (SDH) project website, which provides geologic and hydrologic information for the transboundary San Diego–Tijuana area, USA and Mexico. This website provides background information about the project; a variety of news items; a large amount of data, in particular for USGS multiple-depth, monitoring-well sites; geologic and hydrologic models; and additional resources including photos, illustrations, and references.

Last updated: July 2023.

Some additional data may be available from the USGS database National Water Information System (NWIS).


Questions about San Diego Hydrogeology? Please contact Wes Danskin (email: wdanskin@usgs.gov or send a letter). 619.225.6132