The accurate assessment of dehydration is crucial in many diverse clinical applications. Currently used methods for assessing dehydration rely on either skin pinch tests or analysis of urine. Therefore, therefore is a need for wearable non-invasive devices for continuous dehydration monitoring. This paper presents a novel sensor design for the monitoring of dehydration levels by the use of chipless microwave resonators. The sensor design incorporates a metallic layer beyond the tag sensor itself, resulting in an isolation of the dehydration sensing system from conflicting ambient signals that provides a targeted sensing system to the tissue itself with reduced interference. The sensitivity of the sensor is high, with a ~100 KHz shift for a 1% change in dehydration).