Welsh water have a storm flow map which is updated daily on releases. I have started monitoring these releases to try and work out the pattern- if there is one. And why they happen- given no storms for the last 3 months. This is a image of the area where welsh water have works or storm overflows in the area which ends up in the Taf and so the estuary. The paler symbol in the above screen grab is a overflow that has released in the last 24 hours. I will update the spreadsheet