Live map

We’re pleased to be launching our interactive map ahead of legislation and hope it will increase transparency for our customers, who understandably are interested in the operation of overflows within their local area and across the region.

We’ve decided to launch this map now ahead of bathing water season so customers can make an informed decision about entering watercourses but appreciate there are many other considerations to think about too such as currents, depth, temperature and any inputs upstream.

Whilst we aim to deliver continuously accurate data, our monitors work in challenging conditions measuring fine margins so we do experience false readings and calibration issues from time to time. Whilst we try to remove these readings through instrument validation prior to publishing to our map, a number of these have to be removed outside of the real-time environment. That means that it can sometimes indicate there’s a discharge when in fact there’s an issue with the monitor or the monitor is experiencing communication issues. Once we spot these issues, we investigate, but this doesn’t always mean the map will be updated immediately.

Our monitors might show as unavailable at times, and this could be due to: 

• The monitor has stopped communicating with our systems, often they are in remote areas with poor network coverage, and we do get interruptions to data.
• We believe the monitor is producing inaccurate data
• We’ve identified an issue with the device

We’re sorry about any missing information and aim to get monitors working again as soon as we can. This may take some time if the installation location is difficult to get to, for example, if it is in a manhole on a busy road and we require approval from the local authority before we can access it.

Monitors may also be offline if significant investment works is taking place on-site. For example, if we’re upgrading one of our wastewater treatment works the monitor may be offline while we’re doing the work. 

Some unavailable monitors do still record discharge activity, but the data isn't reliable. While a monitor is unavailable, we won't display any further details about it. The monitor could be broken and unable to record active discharges. Or, it could falsely indicate active discharges when there aren't any. We take the monitor offline to investigate exactly what's happened.

We apologise for any missing information and aim to get unavailable monitors working again as soon as we can. 

We make the data available as quickly as we can. Any delays to this happening are due to sensor, communication and system limitations.

The data has to flow through different systems before it's published on the website:

• Monitors take measurements every two minutes or 15 minutes depending on the receiving watercourse status.
• We use a cloud-based data platform to collate and process the alerts from the monitors. New alerts are loaded into the platform every 15 minutes, which are then processed through some initial before being sent to the mapping software to show the latest alerts.

This means data is usually available within an hour of a discharge starting. If there are communication issues, the data is safely stored until connection is re-established. In these instances, data is available later than usual. In rural settings, we rely on mobile phone technology to send the data.

There are a variety of reasons for discharges to occur.

• There could be something blocking the pipe or the overflow that’s causing it to operate when it shouldn’t. Blockages can be made up of things like wet wipes, which shouldn’t be flushed down the loo, or debris and rubble from a damaged sewer
• Groundwater or surface water could be getting into our network when it shouldn’t be. This could be from a pipe that’s been plumbed in incorrectly, a watercourse that’s connected into the network or high groundwater levels entering our pipes meaning they’re filling up with water that shouldn’t be there
• Storm overflows can also discharge when it’s not raining if they cover a large catchment. This can happen when it’s rained heavily in one part of the catchment, which might be a different village or town, and it takes some time for the flows make their way to the wastewater treatment works – and when it finally does, it can overwhelm that part of the network. The wastewater will be screened, settled in storm tanks and be diluted by rainwater.

Our monitors only measure the start and stop times of discharges. We don’t hold data on discharge volumes in the same way that river volumes aren’t measured.

We understand that it can be frustrating to see an overflow discharging for multiple days. We want to assure you that during periods of heavy or continuous rainfall, or when there are high groundwater levels, the sewer system can become overwhelmed and cause the overflows to act as a relief valve to prevent sewer flooding in our towns, villages and customers’ homes. Our environmental regulator, the Environment Agency, provides us with a permit to release excess water in these situations when we need to get the rainwater out of the system.

However, we do recognise the need to improve our system and reduce these discharges. That's why we’re investing £180m and have submitted plans to Ofwat for approval, which includes a further investment of more than £1bn to reduce the use of storm overflows from 2025 onwards.

It's possible that this is also a surface water outfall, which is designed to discharge rainwater from impermeable areas like roads and buildings into a nearby watercourse. However, to ensure that everything is operating as it should, could you please provide us with the location so that our teams can investigate and confirm that there are no issues?

View our historic data

We understand how frustrating it is for our customers to see and hear about pollution in Yorkshire’s rivers and seas. As part of our efforts to improve, we’re investing £180m over the next couple of years to reduce discharges. We have also recently submitted plans to Ofwat for their approval, which includes an investment of more than £1bn to reduce the use of storm overflows.

This map shows the current status of the monitors as well as the most recent discharge.

View our historic data from our 2023 interactive EDM map

Our annual EDM report to the Environment Agency uses the 12/24 counted discharges method.

Within the annual report, one or more overflow events within a period of 12 hours or less will be considered to be one discharge. One or more overflow events over a period of between 12 and 36 hours will be considered to be two discharges. Each subsequent 24 hour duration counts as one additional discharge and the whole of the 24 hour block is included.

Find more information on how the Environment Agency regulates storm overflows.

Some of our locations have more than one monitor fitted. If any of the monitors indicate a discharge, the pin will go blue. It will only go green once all the discharge points at that location have stopped.

The pins on our map show the location of where the overflow is and therefore the monitor is located as this is a requirement of the legislation. This isn't necessarily where the discharge would be made into the watercourse. Sometimes these monitors are in manholes in roads as this is where the overflow is, and it'll then flow through a pipe into the watercourse. On the map there is the detail of where the overflow discharges to.

The Safer Seas and Rivers app shows a discharge alert for overflows that have been active at any point in the last 48 hours. Our map shows near live data and will only be showing that it’s operating if it is currently discharging, if it then stops it will then change to recently operated.

If there's a discharge or sewage problem we don't know about about, please report it so we can get it sorted.

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A dry discharge is when a storm overflow may operate on a day when it’s not been heavily raining or had any prolonged rainfall.  

We understand our customers’ frustration about pollution in Yorkshire’s rivers and seas and we’re working to improve our performance. There’s a few reasons why discharges might happen when it’s not raining which includes a blockage in the pipe or overflow which blocks the flow or groundwater or surface water has gotten into the network when it shouldn’t be there. Another reason is if the overflow covers a large area and heavy rainfall in one area can mean the flows may take time getting to our wastewater treatment works and overwhelm that part of the network. This wastewater will then be screened, settled in storm tanks and diluted by rainwater. We’re working to tackle these issues and we’re committed to playing our part to help improve water quality in Yorkshire and investing £180m before April 2025 to reduce the use of storm overflows. 

We completely understand the frustration around pollution in Yorkshire’s rivers and seas, and we’re sorry we didn’t tackle the issue sooner, but please be assured we’re working to turn our performance around. In parts of Yorkshire where we know high groundwater levels get into our network, where we can, we’ll try to remove any incorrectly connected pipes or drains and reline the inside of our sewers to stop water seeping in through small cracks or joints.  

If the storm overflow has a large available land, we’re looking at nature-based solutions such as wetlands to help the network from being overwhelmed when the flows get to the wastewater treatment works. 

Dry discharges can also happen because of a blockage in the pipe or overflow, which could be unsuitable items being flushed down the loo, debris or rubble. So we’re investing in smart monitoring systems to help us keep an eye on our network and predict when there might be a blockage, so we can fix any issues before they even happen. 

The rivers are displayed if you zoom in on the map. If you know the direction of flow for the river you can work out if it’s being affected. 

We've kept the surface water outfalls off our map for a couple of reasons. Firstly, we don't own many of them, so it's tricky to get all the information we'd need. Also, there are already over 2,100 overflows shown on the map, and we're worried that adding more would make it too crowded and confusing. We want to keep things clear and straightforward for you! 

We understand how important it is to have all the information easily accessible. However, at this time we'll be focusing on displaying the most recent discharges on the map. Don't worry, we're still committed to transparency and will make sure all the data for the year gets to the Environment Agency as usual. They'll publish this in their EDM (event duration monitoring) annual return report at the end of March, so you'll have all the details then.