We're developing a solution that will work by corroborating the outfalls' physical locations with river catchment data sourced from the environment agency to create an accurate and future proof analysis of the sewage pollution in Dorset and the wider south-west.
The WHO recommend against swimming in a body of water affected by a discharge for at least 48 hours after the end of the event. This website works by checking all of the storm sewer overflows upstream of Poole Harbour, Christchurch Harbour, and Poole Bay. If multiple overflows are operating at the same time, they're counted as a single discharge. If you would like to see how this is calculated, the workings are shown in the browser console.