San Diego Hydrogeology


Sweetwater - SDSW (17S/2W-28R4-9)

Lithologic Summary

Land-surface elevation is 17.40 feet above NAVD88. Depth is in feet below land surface.  Drilled by U.S. Geological Survey using hydraulic rotary, August 12, 2009. Total depth drilled 2006 feet. Screened intervals: 1810-1850, 1300-1320, 960-980, 540-560, 170-190, and 45-65 feet.

Depth (ft) Description
From To
0 28 Gravelly sand, M-VC w/ granules; Lt yellowish brown (2.5Y (6/4)
28 38 Silty sand, VF; Olive brown (2.5Y 4/3)
38 63 Gravelly sand, M-VC sands w/ granules to medium pebbles; Yellowish brown (10YR 5/6)
63 115 Sandy clay, FV-M; Brownish yellow (10YR 6/6)
115 154 Sandy gravel, gran-med peb and M-VC; Lt yellowish brown (2.5Y 6/3)
154 182 Silty clay; Brown (10YR 4/3)
182 278 Sandy gravel, gran-med peb and M-VC; Lt. yellowish brown (2.5 6/3)
278 296 Clayey sand, M-VC; Dark yellowish brown (10YR 4/4)
296 338 Gravelly sand, F-VC and gran-sm peb; Lt yellowish brown (2.5Y 6/4)
338 465 Gravelly sand, M-VC and gran-med peb; Lt olive brown (2.5Y 5/3)
465 580 Slightly silty gravelly sand, VF-VC and gran; Lt yellowish brown (2.5Y 6/3)
580 596 Gravelly silty sand, VF-VC and gran; Olive (5Y 5/3)
596 740 Gravelly sand, VF-VC and gran-med peb; Grayish brown (2.5Y 5/2)
740 880 Clayey silt with shell fragments; Very dark gray (2.5Y 3/1)
880 1,030 Clayey silt; Very dark gray (2.5Y 3/1)
1030 1,040 Sand, VF-M with shell fragments; Very dark gray (2.5Y 3/1)
1040 1,115 Clayey silt; Very dark gray (2.5Y 3/1)
1115 1,180 Clayey silt with shell fragments; Very dark gray (2.5Y 3/1)
1180 1,278 Clayey silt; Very dark gray (2.5Y 3/1)
1278 1,360 Silty gravelly sand with some shell fragments; Very dark gray (2.5Y 3/1)
1360 1,460 Slightly gravelly silt/clay; Olive gray (5Y 5/2)
1460 1,575 Slightly sandy silty clay, F-C sand; Olive gray (5Y 5/2)
1575 1,605 Clayey/silty sand, F-C sand; Olive gray (5Y 5/2)
1605 1,635 Silty clay; Olive gray (5Y 5/2)
1635 1,710 Sand, M-VC; Olive gray (5Y 5/2)
1710 1,785 Gravelly sand; Olive gray (5Y 5/2)
1785 1,850 Sandy gravel, partially cemented, well compacted, cobbles; Dark grayish brown (10YR 4/2)
1850 1,918 Slightly silty sand, VF-C sand; Dark grayish brown (10YR 4/2)
1918 1,962 Sandy silt, VF-VC sand; Dark gray (2.5Y 4/1)
1962 2,006 Silty sand, M-VC sand (1962' to 1980'); VF sand (1980' to 2006'); Dark gray (2.5Y 4/1)

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