High tides this have breached the inner bank at Horsey Island at Braunton Marsh more of the same is expected tonight.
Last night (Sunday, September 29) water was filmed flooding over the inner bank in what is thought to have been a record high tide, with tonight's expected to be slightly higher at around 8pm.
It is understood contractors are on site today (Monday) repairing some of the damage in advance of high tide at around 8pm.
The video here, filmed by Braunton Community News, shows the extent of the breach last night.
Dozens of fish were left stranded by the receding waters.
The Environment Agency has issued a flood alert for the Barnstaple, Braunton, Ilfracombe and Combe Martin areas, saying that heavy rainfall is expected from this afternoon into the evening.
In a statement, it said: "We are working with partners to determine what actions are required for the defences around Horsey Island.
"Property owners on Braunton Marshes are encouraged to keep up to date with the local news reports, and take action if required or these messages are updated.
"Take care near the areas of concern and monitor your local weather conditions. We will monitor the situation and update as required."
The outer bank of the Horsey Island defences was overwhelmed in late 2017 and again in January 2018.
It is not yet known what could happen with flooding and potential damage to the inner bank.
The Gazette has contacted Jasmine Chesters, chairman of the Marsh Drainage Board, for an update on the situation.