A NEW information plaque has been unveiled at ‘the best place in the world’ to see mega tides, with the fastest rising tide in the world and the third largest tidal range, as the rivers Wye and Severn prepare for the first of this year’s peak high tides next week.

The new plaque, mounted on the flood defence wall next to the 203-year-old Chepstow Bridge over the River Wye, compares mega tides across the globe. It was researched and designed by John Burrows, who has been measuring high tides at Chepstow for the past 10 years.

The plaque was made by local potter Ned Heywood and shows that the Severn Estuary has Europe’s highest tidal range.

“Chepstow is probably the best place in the world to see high tides,” John said.

“The full range of a world mega tide is usually a kilometre offshore, but at Chepstow it is within 50m of the river bank, and you can stand directly above it on Chepstow Bridge, alogside Chepstow Castle.

“The largest tides since 2015 are due soon. The first 14.5 m (46ft) high tide is due at Chepstow at 8.47am on Thursday, February 21, and at 9.30am the following day, with an incredible 14.6m (48ft) high tide due on Friday, March 22.

“The astronomical tides at Chepstow and in the Severn Estuary do not exceed 14.7m, so 14.6m is very rare.

“The highest tides are impressive to watch from a safe path and will not create damage unless accompanied by a storm surge.

“This sort of surge can result from the wind blowing from the south west directly up the Bristol Channel and Severn Estuary and low atmospheric pressure, or high rainfall, or snow melt.

“If these meteorological conditions combine with the high ‘astronomical’ tides (caused by the Moon and the Sun) then tides could be up to 1.5 m higher than predicted.

“The highest tide recently in Chepstow was on January 3, 2014. A one-metre storm surge on top of a 14.2m astronomical tide, created a 15.2m (50ft) tide at Chepstow Bridge,” he added.

“Chepstow has the world’s third highest tide and the world’s fastest rising tide – capable of rising 13m (43 feet) in four hours.

“The days with the highest tides this year also have the lowest tides of the year and these are interesting to look at as well to see what is on the river bed.”

A tides information leaflet published by Chepstow Town Council is also available.

See it online at www.chepstow.co.uk