26th April: When Calshot was an Island!
Calshot Spit as depicted by John Speed in 1611
One of those random posts selected for me by Facebook showed John Speed’s map of the Isle of Wight. It appeared that Calshot Castle was cut off from the mainland, but, since the Facebook reprodution was not that clear, I bought a larger facsimile copy from The Old Map Company. On the Speed’s map, not only is there a clear channel shown, but there is an area of stippling similar to that used to depict the Bramble Bank suggesting that an area was underwater, or at least awash, with the tide in. The version I bought claimed to be published in 1627 but I’ve later found that there were previous issues including one published in John Speed’s atlas, “Theatre of the Empire of Great Britaine” in 1611. All are identical with regard to the depiction of Calshot Spit.
Repairs to Calshot Castle In 1612, Buhler C.F. (1952) with interpretation after Ian West
Ian West’s comprehensive website drew my attention to an estimate for the repair of Calshot Castle in 1612 (Buhler C.F., 1952) written by “His Majesty’s Surveyor” John Norden. The greatest cost is for repair to a breach in Calshot Spit described as follows:
“This breach being a thing much to be respected for that if it be not repaired, there will be shortly no passage without boat, to or from the Castle — as yet there is passage for horse and man at a low water, and it will cost the repairing,..either with stones or clay (but I take clay [to be] the surest & fittest) with some aid of the Country whom also it doth much concern about – £201.
“There must be wood allowed out of the [New] forest, to make a defensive hedge against the violence of the sea while the work is in hand, according as occasion shall require.”
This wording suggests that the breach was in 1612 relatively recent. I have looked through the “Old Hampshire Mapped” website to try to determine the history of this breach. In the early maps the accuracy of the coastline is very variable but comparing the depiction of Hurst Spit and Calshot Spit perhaps gives some guidance.
Significantly the 1595 map of Hampshire was surveyed and drawn by John Norden and shows Calshot Spit as continuous. So the breach occurred between 1595 and 1611. The spit is still shown as breached in a survey of Southampton Water and Solent by Edmund Dummer and Capt. Thomas Wiltshaw for the Royal Navy in 1698. However maps from 1767 and 1788 show the spit as continuous.
The breach in the beach berm at Lepe in April 2024
What caused the breach? In April 2024 a storm surge resulted in a record high tide which caused overtopping of Calshot Spit by waves. At Lepe a major breach in the beach berm was created which caused flooding into the nature reserve beyond. It appeared that the breach was caused by a combination of over topping by waves and back flow of the water through the shingle berm.
In 1607 there was a storm surge which caused a major inundation of the Somerset levels. It is estimated that 2,000 or more people were drowned; houses and villages were swept away, and an estimated 200 square miles of farmland and much livestock destroyed. The same storm also caused flooding at Kings Lynn in East Anglia.
However exceptional weather events were common during the period 1560 to 1630 (known as the Grindelwald Fluctuation) during which a cooling of the Earth’s climate has been ascribed to major volcanic eruptions (e.g. Jones et al. 2021). Thus, while the 1607 storm surge seems a likely explanation, the breach may have been caused by a different storm.