Some of the region's most popular resorts are facing an uncertain summer after their beaches were closed to bathers because of poor water quality.
'No-swim orders' have been in place for a number of days on beaches between Heacham and Wells, including at Hunstanton.
The orders were imposed by the Environment Agency after its water monitoring systems predicted large amounts of pollution.
Experts have identified a number of factors behind the problems, including waste from some homes and campsites not fitted to the mains sewers, and rain and high tides washing bird and animal droppings out to sea.
Some of the orders, which are put in place either by the council or the beach owner, have since been lifted, but local businesses and politicians have raised concerns about the impact of the warnings on visitor numbers as the peak tourism season approaches.
At Wells red warning flags have flown at the beach for four of the last six days.
They were taken down on Monday, but locals are still concerned about what they could mean for the vital tourism sector.
Roger Arguile, a town councillor at Wells responsible for tourism, said: "Any news about water quality is bad news for intending tourists. It's likely to make them less wanting to come."
Mel Catton, chairman of the town council, said the flags had come at the worst possible time for the town.
“It is certainly not good for Wells, any restrictions are not good for the town.
WELLS: The Council is pleased to confirm the Environment Agency’s Swimfo site is showing there are now no active water quality alerts in place for Wells.
— North Norfolk District Council (@NorthNorfolkDC) August 7, 2023
It is therefore safe for the public to responsibly enjoy bathing and paddling. pic.twitter.com/Hzi9E8f3ah
"It is annoying for it to happen right at the peak of the season. It could have happened before the start of the summer holidays and perhaps would not have had this same reaction. It is a difficult situation for everyone.
“It is the kids' holidays, and most people want to bring their family to the beach, but they will be cautious with these flags in place.
“We would like the matter resolved and do not want it to drag on for too long into the season.”
While visitor numbers have been down over recent days due to the bad weather, temperatures are expected to rise this week.
READ MORE - Heacham and Hunstanton: No-swim warnings for beaches
Jason Crook, manager of French’s Fish and Chips on the Quayside, was among those voicing concerns about the possible impact of the red flags on the town's reputation.
“These flags could discourage people from visiting. Families could panic if they see these flags and not come to Wells. Anything that stops people visiting is negative for us."
At Hunstanton, a swimming ban remained in force yesterday.
Amanda Bosworth, chairwoman of the Hunstanton Society, said: "I'm very concerned about it.
"I'm a member of a cold water swimming group and it's put me off going.
"We're a coastal town and it's got to have the potential to impact on our economy."
Harry Blathwayt, portfolio holder for the coast at North Norfolk District Council, said: “The current situation is unsatisfactory, and I think everyone must recognise that it is of interest why this is coming up more this summer than in previous years.
"My ward, Sea Palling, lost its blue flag this year, so I want to understand why this is happening.
“We've had a lot of rain this year, is this merely storm drain overflow or is this being caused by additional housing which is generating this issue?
"We need to get to the bottom of this.”
WHY ARE THE RED FLAGS FLOWN?
The no-swim orders are issued by the Environment Agency, which describes them as ‘pollution risk forecast alerts’.
They are based on data predictions and modelling, taking into account rainfall, wind and tidal patterns.
They do not necessarily indicate sewage entering the water from storm overflows.
At Wells, one of the factors has been a so-called marsh tide, where coastal marshes flood on the high tides, washing bird droppings and rabbit droppings out to sea.
At Hunstanton, bird droppings on the roof of the town's leisure centre have been washed into the sea by the recent rain, contributing to the problems.
The rain has also washed pollution from streets and pavements into the sea.
The EA has also said it suspects so-called 'misconnections' from local housing and campsites, where toilets or waste water are allowed to discharged into storm drains rather than the sewerage system, could account for some of the problems.
A spokesman for the Environment Agency said: "These forecasts are based on rainfall, wind and tidal patterns and alert people when water quality may be poor.
"Thundery showers and intense rainfall increase the likelihood of pollution entering the sea and rivers from many sources, including agricultural runoff, storm overflows and highway drainage."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here