An Extraordinary High Tide at East Mersea

17th February 2026

A lovely sunny day at Cudmore Grove and was therefore a bit surprising that I almost had the whole place to myself. I started off by walking along the borrowdyke leading to Stone Point. As usual the borrowdyke was full of Wigeon sleeping in the margins after a couple of hours grazing on the meadows.

Behind the borrowdyke 1000+ Brent Geese were grazing on the meadow accompanied by a handful of Curlews.

Now on to Stone Point and was immediately welcomed by the Turnstones feeding on the water's edge.

And never far away the site speciality the Sanderling busy chasing the waves.

Even more flying in now with the occasional Redshank.

Now a walk along the sea wall from Stone Point to the Oyster Fishery. Waders were already starting to gather for the high tide roost on and around the pools on the saltmarsh like these Dunlins, Curlews, Grey Plovers and Redshanks..

 

Many of the Brent Geese had flown from the meadow and were now feeding on the saltmarsh and shallows.

And still more flying in all the time.

On the way back a 2nd winter Mediterranean Gull flew past, not particularly unusual you would think, but the first I have ever seen at East Mersea. I have seen several Med Gulls on Mersea before but all at Sea View.

And what is going on here?As I approaced the wader high tide roost pools I could see the water levels were exceptionally high with the islands almost underwater and many of the waders displaced to higher ground.

Well what a fantastic day at my favourite East Mersea. I had checked the tide before setting off and high tide was predicted to be at 12.20pm with a height of 4.76m, a very average height. Therefore when I arrived at 10.20am, two hours before high tide, I would expect there still to be some bare mud and the incoming tide would push the waders closer to shore, but today every square inch of mud was already underwater.

Also, when I walked back from the Oyster Fishery there were very few waders in the high tide wader roost pools because the water was very high, the small islands were virtually underwater, and the pools were joined to the river, so many of the roosting waders had to go in search of higher ground.

I found out this was because of a storm surge. Storm surges are caused when a strong northerly wind as today pushes the North Sea southwards until it meets the restriction at the eastern end of the Engish Channel, which causes it to back up and causes exceptionally high tides down the east coast. Based on my experiences with the normal tides at East Mersea todays surge added an extra 1 metre to the tide. This was borne out when I went to the Strood causeway to leave the island an hour after the predicted high tide and still had to wait a further 20 minutes for the flood across the causeway to subside. For a 4.76 metre high tide the causeway would not be covered.

My special thanks go to Andy Field for the storm surge information.