Coast and rivers watch

Check for recent storm overflow (CSO) discharges in our region using our interactive map.

Check our map

We have installed monitors on all 1,295 storm overflows in our region.

These monitors feed into our interactive map, which shows where they are and provides live information about when they operate. The discharge data is refreshed every 15 minutes.

It also shows rainfall levels and provides alerts about storm overflows impacted by high groundwater levels, which can cause discharges during dry weather.

Chisel beach on a sunny day

About our monitors

Why have we installed them?

We have installed monitors on our storm overflows to:

  • be open and transparent with customers and stakeholders about discharges
  • identify the ones that operate most frequently so that improvements can be made
  • help the Environment Agency monitor our performance.

How do they work?

Our monitors typically track the level of flow entering our sewer network. When a sewer reaches max capacity, the monitor will trigger an alert, meaning the overflow is operating.

They monitor when a discharge starts and finishes. They do not measure the volume of the discharge. The map also shows the type of discharge, including whether it is mainly groundwater or has been partially treated.

How accurate are they?

Our monitors are usually very accurate, but weather, debris, vegetation, animals and insects can occasionally trigger an alert when a storm overflow isn't operating.

We work hard to ensure our monitors are as reliable as possible, which is why we sometimes need to take them offline for cleaning, maintenance and refurbishment.

We are also continually developing our system to prevent false alarms and increase confidence in our data.