This line shapefile represents the depth to groundwater below the ground surface in California during the spring of 2015. This layer is a smoothed approximation of the groundwater level 'surface' based on the measurement data. The measurement values may not exactly match the contour values because of the contour smoothing process. Depth information is represented in feet below the ground surface. Water level measurements are selected based on measurement data and well construction information (where available) and approximate groundwater levels in the unconfined to uppermost semi-confined aquifers.This layer is intended to be used as a compliment to data, reports, and other information provided by the California Groundwater Information Center.