Devices, methods and systems for wave and water level measurement using a single DC (direct current)-coupled CW (continuous wave) Doppler radar for detecting water elevation changes in time when installed up to several meters from the water surface. The radar is wireless and can stream continuous data to a local PC (personal computer) or base station in range of its radio. The radar can sample up to 40 Hz and can run on batteries for continuous sampling. The radars can include multiple radar configurations of 1, 2 and 4 radar configurations. Applications for this radar can include the measurement of beach run-up, free surface elevation in tidal zones, and storm surge elevations near bridges and critical infrastructure during storm events.