Department of Water Resources Home

Levee Repair - Geotechnical Evaluations

DWR Levee Repairs Program
Department of Water Resources

3310 El Camino Avenue,
Suite 140
Sacramento, CA 95821

Mailing Address:
P. O. Box 219000
Sacramento, CA 95821-9000

For public comments or questions e-mail:

Geotechnical field crews drill borings to collect soil samples from a flood control levee. Geotechnical subsurface investigations (drilling to collect core soil samples and cone penetration tests) are underway along the American River.

The investigations, which include cone penetrometer testing (CPT) and drilling borings to collect soil samples, will be conducted through mid-May. Crews with drill rigs and CPT rigs (shown to the left and below) may be visible on the levees during normal daytime working hours.

American River Map and Schedule

Please note that because the schedule is fluid and susceptible to weather, access, and other conditions, dates are subject to change. The map/schedule will be updated with current information as it becomes available; please check back frequently for the most up-to-date information.

For media inquiries, please contact Elizabeth Scott, DWR Public Affairs, at (916) 835-5344.

CPT rig with probe deployed. Much of the geotechnical evaluation of levees and levee foundations is done by relatively straightforward methods of drilling, boring, and pushing cone probes to collect samples and evaluate subsurface soil conditions.

Ongoing subsurface explorations being conducted as part of the levee evaluation program are based on levee-specific investigation plans that typically call for collecting samples at 1,000-foot intervals along the levees. Additional landside explorations are also being performed to better define existing subsurface conditions.

Collected samples are analyzed in laboratories to help characterize subsurface soil conditions and identify potential problems or weaknesses in the flood control structures. These tests look at such factors as moisture, density, soil grain size distribution, and shear strength.

A field crew member prepares a sample for laboratory analysis. As the geotechnical team performs its investigations, specialists also conduct biological surveys and cultural resources screening to protect wildlife, habitat, and any archaeological resources.


Cone Penetration Testing (CPT) At-a-Glance
Subsurface Exploration (Drilling) At-a-Glance

Map of Sacramento River Explorations (completed)
Map of Davis Explorations (completed)
Map of Woodland Explorations (completed)