This dataset contains daily S-wave velocity models derived from time-lapse elastic full-waveform inversion (FWI) conducted over a two-year period (2021–2023) along Sandhill Road, California, for groundwater monitoring, along with analysis code. It also includes virtual source gathers retrieved from December 2022 and two days of continuous distributed acoustic sensors (DAS) recordings. Seismic data were acquired using a novel, noninvasive technique that leverages existing telecommunication fiber-optic cables as DAS and uses vehicle traffic as repetitive Rayleigh wave sources. The dataset provides high-resolution spatiotemporal measurements of subsurface S-wave velocity variations, capturing groundwater table dynamics in response to rainfall events.