Provision of Data - Welsh Water

Storm overflow map (with sites in the Menai catchment included)

The map provides near real-time information about the activity of our storm overflows, as indicated by their monitors.  The map icons will indicate if they are operating, not operating or if they have operated in the past 24 hours. To begin with, the map shows storm overflow activity at designated bathing waters (inc Menai Straits designated Shellfish Waters).  It also includes non-designated swimming sites, as identified in the Swim Survey we undertook last year (which around 1,800 people responded to) inc storm overflows on the Afon Cegin and Ogwen at Bethesda.

Over the coming months, more storm overflows will be added incrementally until it includes all 2,300 of our storm overflows, which we will complete before March 2025 at the latest. The map cannot give information on water quality as storm overflows are just one of a number of factors that may be impacting an area/watercourse. A link to the map is available here