Birmingham Anglers Association

The weed was stripped out of the Severn during the huge floods of 2019 - 2020. It has not grown back since.
I believe that the phosphate, herbicide (weed killer, routinely spread on fields in August/Sept to 'speed up ripening of crops') and fertiliser pollution has been the main problem - the river was just about surviving up to 2019. It now no longer has the capacity to regenerate, not helped at all by the insane decision by the government in 2021 to allow sewage discharges throughout the year (and not just in times of high river levels).
The Teme was the dire warning that we have to give our rivers more respect and care - it just took the Severn a little longer to collapse due to its bigger catchment/volume.

http://www.shropshirestar.com/news/local-hubs/south-shropshire/2017...