There a many sites now offering river height information, often with different options, however they all use the Environment Agency's data, so listed below are links to the pages relevant to Bewdley.
That said Gauge Map is a popular one that may also be of interest, which you can access here: Open Gauge Map for Bewdley
River Gauge Map
The map below shows the River Severn from Montford to Bewdley. The measuring stations that are upstream of Bewdley are highlighted in red.
Montford Measuring Station
Water levels displayed at Montford station takes on about 20 hours to get to Bewdley.
Shrewsbury (Welsh Bridge) Measuring Station
Water levels displayed at Welsh Bridge station takes on about 10 - 15 hours to get to Bewdley.
Bridgnorth Measuring Station
Water levels at Bridgnorth station takes about 5 - 6 hours to get to Bewdley.