The embankment monitoring system comprises an optic sensor chain (10) and an interrogator (20). The optic sensor chain (10) comprises a series of intrinsic fiber optic sensors (12) that are mutually spaced with respect to each other in a longitudinal direction of the optic sensor chain and at least one optic fiber (14) to optically connect the plurality of intrinsic fiber optic sensors to the interrogator. The interrogator is configured to issue an optic interrogation signal and the intrinsic fiber optic sensors are configured to respond to the optic interrogation signal with an optic measurement signal that is indicative for at least one physical parameter (P1) sensed by the intrinsic fiber optic sensors. The interrogator is further configured to process the optic measurement signals of the intrinsic fiber optic sensors to estimate a depth (d) as a function of a position (p) along said optic sensor chain (10).