The flood warning system relied on by hundreds of thousands of households in England will be put on permanent autopilot, officials have said, despite warnings it is inaccurate.
The Environment Agency has been trialling an automated flood warning system since December, when strike action by workers over years of below-inflation pay deals left gaps in incident rosters.
But members of the public who rely on it say they have received warnings of floods that fail to materialise, or that warnings have come after their homes are already inundated.
And even when warnings are accurate, users have said the level of detail on offer from the automated system is far less than the regular system, forcing people to guess the level of impact.
Nevertheless, a senior executive at The Environment Agency has said they will continue using the automated system even after they have resolved the dispute.
In an internal staff briefing, seen by the Guardian, Caroline Douglass, the agency’s executive director for flood and coastal risk management, described continuing the use of automation as “a logical step that we need to take”.
Speaking in January, Douglass said that although “many of the communities aren’t happy with what they’ve been getting” automation would be implemented “because, the point is, we have the technology and we do need to use it”.
Under normal circumstances, The Environment Agency’s flood warning system, which covers at-risk areas across England, is staffed by flood forecasters in 14 different areas 24 hours a day.
Readings from the river sensors are fed into computer models, which send alerts of potential floods to workers who will assess whether they are realistic, based on their knowledge of local geography, weather forecasts and groundwater levels.
Trained and experienced staff can then decide whether a flood warning should be issued, with up to three layers of human intervention before the most serious severe flood warnings – issued if there is a danger to lives – are sent out.
“So it does need a bit of training and a bit of human intuition to understand how the rivers react, and that local knowledge is really important,” an Environment Agency worker, who asked to remain anonymous, told the Guardian.
The automated system simply takes away the human element, with warnings issued automatically if sensors reach a certain threshold for a certain length of time. That means there is no human intervention to double check if the readings are anomalous or the predictions unrealistic.
Heather Shepherd, of the National Flood Forum, which advocates for communities at risk of flooding and maintains a network of local groups, said the automated system had led to a number of false alarms.
She described how in January warnings were issued around the River Severn predicting the worst flooding in recent memory, prompting her to spend two days preparing for disaster.
“Everybody was on high level prep. And, of course, do you know what? We didn’t even flood,” Shepherd said. “Nothing, nothing at all. Not a drop. It didn’t even come. I was up all through the night, walking down to look into the yard, to see in the street, see where it was, [and] nothing.”
Sources familiar with the automated system said false alarms were more likely than failures. But on 14 January, residents living near the River Wye in Herefordshire received a flood alert – the lowest level of warning – that came 24 hours after the highest peak in water levels for three years.
One resident of that area who emailed the Guardian described how that alert came after his home was already flooded.
Trade unions representing Environment Agency workers criticised the plans to increase automation of the flood warning system, which they said they had not been consulted on. Ben Middleton, national secretary at Prospect, said: “As one of the unions representing staff at The Environment Agency, we do not believe this will be an effective way of warning the public about potential floods.
“Without human review, warnings may be issued unnecessarily and cause undue alarm if faulty readings are given by the equipment. Automated systems may also fail to recognise fast-developing problems, which an expert staff member with experience of a particular area would be able to spot. To be effective, automation relies upon properly trained staff to service and maintain the equipment and to analyse and interpret warning triggers.”
Donna Rowe Merriman, head of environment at Unison, said: “Human judgment is irreplaceable when it comes to serious environmental issues. Dealing with deep staff shortages and resolving strikes must be the agency’s priorities, not relying on a flimsy and faulty automated system.
“The bottom line is that employees are underpaid and leaving en masse, meaning services aren’t operating safely. Without a pay boost to stop the staff exodus, there’s a serious risk of irreversible damage to rivers, coasts, properties and whole communities.”
An Environment Agency spokesperson said: “We are committed to improving the accuracy of the automated flood warning system and have taken on board feedback from the public when doing this.
“The automation of flood warnings has been developed as a mitigation for ongoing periods of industrial action to ensure that community members continue to receive timely information about their flood risk. We will review its use at a later date to determine whether it could contribute to our future flood warning service.”
