The use of time domain reflectometry (TDR) to monitor movement in embankments and slopes is an emerging technology. TDR was originally developed for the telecommunication industry to locate breaks in cables. TDR is a time dependant pulsing electronic signal that detects changesin the impedance of a coaxial cable. Deformations such as cimping or shearing of the cable can be located quickly and accurately. By installing either vertical or horizontal cables in embankments or slopes, movement of slip planes, shear zones, or tension cracks can be easily detected. This paper reports on the use of TDR to monitor 20 to 30 feet hight embankment levees in the Sacramento / San Joaquin Delta region of Nother California.