The Inning of Brading Haven

In determining the geography and the nature of Sir Hugh Middleton's embankment and reclamation, a number of pieces of evidence need to be considered, as a result of which a more reasoned appraisal can be made.

In his book Bembridge Past and Present, Ernest du Boulay wrote that Middleton's embankment ran from "Woodnutt's sailmaker's store"on the end of St. Helen's Duver in a straight south-easterly line across to a point under the grounds of "The Lodge". Other publications, basing themselves on du Boulay, have reiterated his findings and consequently his words have become the standard accepted view. This is somewhat puzzling, given the inaccuracies that abound in his book. However, du Boulay may be forgiven slightly since it seems that he may have based his conclusions on a map produced by the engineers of the 1879-80 reclamation. Unfortunately, over the years, a number of misleading layers of information have covered the original evidence, and these layers need to be stripped back to reveal the underlying facts.

Parish boundaries
The alignment of old parish boundaries are significant and can often reveal useful information about ancient topograhy and geography. Parish boundaries usually followed natural features or boundaries and where they followed a river or waterway, as they often did, then the boundary was set down the middle of the waterway. In this case, the boundary between the parish of St. Helen's and Brading is a significant feature.

Until the twentieth century, the dividing line between these two parishes lay through the north-west end of what is called today "St. Helen's Duver". The parish line passed through the southern part of the garden of the easternmost of three detached houses in Dover Road, close to St. Helen's seamark. The three houses are constructed on land that has been built up to form a platform. The lawn of Moorlands House shows the more natural level of the land. This boundary is clearly shown marked on the 1842 tithe map of Brading parish (JER/T/32), the John Andrews map of 1769 and the 1862 Ordnance Survey map, suggesting that the original mouth or river outlet of Brading Haven was on the St. Helen's side. Early maps of the Island also support this. Speed's map of 1610 clearly shows the duver extending like a narrow spit from the Bembridge side with the outlet next to the original St. Helen's church. This is also confirmed by the map commissioned by Lord Burghley in about 1590, which shows a similar alignment.

Ownership of the Duver
The name given to the duver is also indicative of its past geography. On the 1842 tithe map, it is called "Brading Dover" and had been known by that name continuously until then. Until 1781, it had always formed part of a large estate comprising most of the Bembridge peninsula. and was firmly a part of the Bembridge estate. From 1616, this estate had wholly belonged for almost two centuries to the Worsley family as part of their Bembridge properties. In 1774, Sir Richard Worsley had a map of his Bembridge estate drawn up. On this, the duver is marked as the "Duffer". The accompanying schedule also shows that the Worsley claimed the Haven too, which has always been called either Brading Haven or "Bimbridge Marsh als. Bimbridge Haven" (JER/WA/3/39).
Index of Binbridge Manor
Waste included
The Haven725a 3r 28p
The Duffer 38 -- 3
A. At the Haven's mouth 4 1 29
B. Rough Shore 5 2 32
However, in 1781, Sir Richard Worsley conveyed the duver to Nash Grose, who owned St. Helen's Priory and the duver then became part of his St. Helen's estates, although still remaining in Brading parish.
3 March 1781 Conveyance
St. Helen's Dover (38a 3p) abbs: S & E, the sea-low water. W & N, St. Helen's Priory.
1. Sir Richard Worsley Bt. of Appuldercombe Park.
2. Nash Grose of Red Lyon Square, Middx, Sergeant at Law.
Consid: 100
Until the 19th century, the duver was never called St. Helen's Duver, a name which it would have been given if the duver had always been connected to the St. Helen's side. Indeed, the duver was so clearly part of Bembridge that when Middleton's embankment gave way, it was the Bembridge landowner of the duver, Worsley, who was taken to court by the owner of the reclaimed lands, Thelwell, in order to reclaim compensation.

A further piece of evidence arises in "An Account of the State of the Parish of St. Helens in the Isle of Wight given the 24th of January 1640 by Sir Wm Hopkins there inhabiting"(STH/3), in which he states that

"ffive or sixe times since my comeing to this place, in the space of thease 8 yeares last past The washe of the sea in fowle weather hath borne downe all or part of the Church walles, Raysed wth stones as bigg as the Strength of men wth any usuall Art was able to move to the place; And the whole Church, since the takeing in of the Haven; not a little endangered. You knowe, it is very neere the Church, wheare the Newe walls & works were raysed for the takeing in of the Haven. So that the Tides which had an Outlett that way before, fall now, being there Resisted, with all their Weight uppon the Church, And have almost made the Churchyard a Peninsula, And will make it sea if not firmely prevented..."
Not only is this interesting as providing a cause for the rapid disintegration of the original St. Helen's church, but it also provides clues concerning the site of Middleton's embankment. He shows that the walls of this embankment were constructed "very neere" to the church and that the original outlet of Brading Haven was close by too. Sir John Oglander too, writing in his Commonplace book (OG/90/4), confirms this location.
"In 1622 (sic) they made ye banckes at St. Hellens, and so stoped owt ye seae..."
And again later he writes,
"Concerninge Bradinge Haven I am of Opinion yt Originoly when fyrst it wase a Haven, that ye Courrant wase where now it is (next to Bindbridge) and that in time it gott grownd to ye Weastwarde and lost grownd to ye Eastward, untell sutch time as ye Courrant Came next to St Hellins that it Could goe no farthor ffor ye Hill on St Hellens syde, ..."
Again when speaking of St. Helen's church, Oglander mentions that it was situated on the coast "at ye East poynt", suggesting that the shore extended no further than the church.
St. Hellens
This Church wase first Bwylt by Hildila yt wase Chapleyne to Sanctus Wilfydus then Bischopp of Chitchestor he placed it next to ye Open Seae at ye East poynt, that he mygh (sic) ye Oftenor behold Chitchestor ye place of his birth,...
(OG/90/4 f.41)
This point is further supported by the Royal Survey of 1559/60. This was a survey carried out for the King of the whole of the Isle of Wight for defence purposes. It mentioned that the parsonage at St. Helen's belonged to Eton College and that the parish church there needed "to be repayred with spede by cause yt stondeth upon the point of the haven". This same Survey also gives a description of all the landing places around the Island coast and specifically speaks of "Seinte Ellenes Creke" as the inlet of sea at this point.
Seinte Ellenes Creke one mile demi from Netles Heth bereth at full see a faddam water demi and at low water dry
From St. Ellenes creeke unto thest furlonde two miles alonge the cost of Binbridge goode rode and landinge at all tymes
In a letter to Oglander in 1631, Thelwell refers to a letter of Oglander's in which he stated "that the makeinge of my banke in stoppinge the sea of his ould Corrant was the cause of this breach". The use of the word "ould" suggests that the waterway no longer flowed in its original course.

In 1638,a dispute erupted between Sir William Hopkins, "ffermor" of the Priory, and the parishioners concerning the sea defences at St. Helen's church, resulting in a statement of differences between the two parties. It noted the poor state of defences

All wch bancks & firme grounde at the East ende of the Chauncell and Church yarde have wthyn these 12 yeares last past or thereaboute ben foundred & cleare taken away by the sea unto the very Chauncell wall & Churchyarde that bones have falne into the Sea & doe now appeare in the sides of the bancke of the Churchyarde by reason of certayne worke wch Sr Bevis Thelwall hath made neere thereunto to pen the Sea out of her wonted course for gayning of certayne grounds there...(STH/68)
The rocks that made up the foreshore had always afforded a certain amount of protection to the church but it is clear that Hopkins considered them a source of revenue and was selling significant amounts of this limestone to various people, including the governor of Portsmouth, Col. George Goring. However, this had a damaging effect on this area of the coastline, where the removal of the natural barrier of stone had led to accelerrated erosion of the churchyard and its church.
The Parishioners will obiect that the ffermor heretofore sold away the greate stones on the shore wch defended the Church yarde True heretofore before Sr Bevys Thellwalls works they did soe & then since also the parishioners have fetcht away many loads of stone for their necessary use But since Sr Willm Hopkins was ffermor wch hath ben 6 yeares he never sold any stones there
Du Boulay, writing in the first decade of the twentieth century, remarked that "to this day, within its limits, a marked difference in the soil and verdure can be seen by anyone who will carefully look for it." He also noticed "how different the soil, herbage and plants in the gardens of some of the Duver houses are to those further east,..." The reason was "the rich alluvial soil which has here filled up the old channel, so utterly different in its nature to the wind-blown sand forming the soil on either hand."

In addition, as mentioned in the section on the history of Bembridge, a ford called "Yarneforde" is said to have existed across the entrance channel to the harbour. This "Yarneforde" is located in St. Helen's, further suggesting that the outlet from Brading Haven was formerly on the St. Helen's side, not, as at present, on the Bembridge side.

It is clear then that the original channel and outlet passed on the west side of the present St. Helen's Dover. The mouth of this outlet stretched from St. Helen's seamark across to a point slightly to the south of the Baywatch Cafe and this marks the width of the old waterway leading from Brading Haven to the open sea. Today, the carpark, Baywatch cafe and the three houses in Dover Road cover this area.

A possible reconstruction of the Duver spit in approximately 1600.
Based on late 16th century plans, Speed's 1611 map and local topography.

The History of the 'Inning' or Reclamation of Brading Haven.
'Inning'was the 17th century term used by Sir John Oglander for the reclaiming of marsh and tidal mud-flats from the sea by erecting a bank so as to enclose an area, thereby closing out the sea from that area, which could then be turned to pasture, with the subsequent raising in value of that piece of land.

The first recorded inning was that authorised by Sir William Russell of Yaverland in the early 13th century of various mudlands to the south of a causeway and a bridge, called Yarbridge, that he had also constructed. Although Oglander states by so doing, he effectively stopped the sea from flowing south of the bridge, the Cowdrey engraving tells another story. The Yarbridge seemed to carry the roadway across a number of arches, suggesting this was done to allow the tidal waters south of the bridge easy regress on the ebb tide through the bridge as they flowed out northwards. In fact in the Cowdrey picture, six to seven arches are shown. Most of these are either under the present causeway or were replaced by it.

In 1562, George Oglander and German Rychardes reclaimed a large area of marsh, called North Marsh and adjoining marshlands. These were situated in the north-west corner of Brading Haven, immediately to the east of the section of railway line between the railway bridge and Brading. Even today the beds of the former streams that used to run through the tidal mud-flats at low tide can be discerned as snaking depressions in the modern pasture.

The embankments are about 10 to 16 feet high, constructed from compacted clay, covered in turf with a small drainage ditch on the landward side running along the foot of the bank. Today, due to slumping and erosion, the walls are not quite so high in places, and where cattle have collected, parts of the bank have been eroded severely. In his Account books, Sir John Oglander regularly mentions sums of money paid out as wages to maintain these marsh walls or embankments. At the northern end is an overgrown sluice, set into the northern end of the embankment to let out water drained from the pastures but to prevent the sea returning on the flood tide.

In 1594, Edward Rychardes undertook a more challenging project, when he had constructed a bank or dam, running from a point at the eastern end of Quay Lane, near to the old quay, on the Brading side across the width of the haven in a south-easterly direction to a point close to the foot of Centurion's Hill on the Bembridge side. In doing this, he created a large extent of "feeding grounds" to the east of the modern Brading railway station. This embankment stretched across the haven and effectively cut it off from Yarbridge, which was now situated amongst pastures with the waters contained within the banks of the narrow River Yar. Because Rychardes's bank had to take more of the force of the tidal flood of Brading Haven, it had to be made more substantial than the previous 1562 banks. Consequently, a larger outlay of money was required in the building of a stone revetment to reinforce the earth bank. The bank is about 8 to 12 feet high and is made of a clay matrix, with stones distributed throughout. The Brading side of the bank makes use of broken chunks of Bembridge limestone, gathered from a local seam, while on the Bembridge side, broken chalk has been exploited from the nearby chalk pits. The stone face of the bank was also constructed using local Bembridge Limestone in a dry stone wall. A large sluice, called the "great Sluice" was built using coursed stone at the southern end to allow the River Yar to pass into the haven. The River Yar followed the couse of the old river bed that had been cut over the centuries into the mud-flats, uncovered at low tide and along which the waters drained at low tide.

The embankment constructed by Edward Rychardes in 1594
Fig. 1
Fig. 2

Fig. 1 : View of embankment showing stone facing wall from the former sea side.
Fig. 2 : Detail of stone facing wall.
Fig. 3 : View along the top of the bank - area of reclaimed land in 1594 is on left.
Fig. 4 : Section through the embankment shown in Figs. 1 & 3.

Fig. 4
Fig. 3

A far more ambitious project, that had the potential to reclaim unimagined acres of new pasture land, was undertaken in 1620. The driving force behind this attempt was Sir Bevis Thelwell, a page of the bedchamber of James I. Positions at the Royal Court were all based on patronage and royal gifts and grants all depended on connections and influence within that Court. Thelwell understood only too well that he would need to find a favourite of James I, if he were to have any chance of attaining lands or titles, or, in this case, the use of Brading Haven. Indeed, he had acquired a good estate by encouraging James's Scottish favourites to ask the king for various lands "and then himselve bwying of them with readie money under halfe ye value". Thelwell found that favourite in John Gibb, a groom of the bedchamber. Gibb was an older man, who had been a servant of James I's father, and who the king considered as a father figure. Once, Gibb had been granted the use of Brading Haven on condition that he paid the King an annual rent of 20, Thelwell waited to see the outcome of a court action that had been initiated by the local owners of land adjoining the haven, who claimed that parts of it belonged to them. Most probably, this was mainly on the part of the Worsley family, who by 1620 had come into possession of most of the Bembridge peninsula. In later documents, the Brading haven was clearly the property of the Worsleys, presumably coming to them in the early 16th century when they acquired the Wolverton, Hardley and La Wode estates. Oglander mentions that James took a close interest in this case since "itt woold be a leadinge case for ye fens in Lincolnshyre". And indeed the inning of Brading Haven was just one of a number of reclamations, both large and small, that would increasingly take place in the following years in various locations throughout England. In the early 17th century, James I and a number of the more powerful courtiers had become interested in the possibilities offered by the reclamation from the sea of the marginal wastes on their lands. In bringing more new land into cultivation or pasturage, the rents on that land could be increased, thus increasing their annual incomes in a relatively easy step. With this purpose in mind, James I looked towards potential areas of his kingdom, like the Fens and Sedgemoor in Somerset that could be exploited by reclamation. Next, Dutch engineers, the foremost experts in reclamation from the sea and drainage, were invited to England to manage these works.

The most notable of these Dutch engineers was Sir Cornelius Vermuyden, who oversaw the draining of Hatfield Chase in Lincolnshire and the larger, controversial draining and reclamation of the Fens. The latter project was to see the emergence of Oliver Cromwell as a spokesman and champion of the rights of the small Fens landowners. Nameless, less notable Dutch engineers were at work elsewhere in the country, as in the Isle of Wight, on similar but less substantial projects. However, the reclamation of Brading Haven seems to have been a comparatively early case. The draining of Hatfield Chase by Vermuyden did not start until 1626, while the contract for the vast undertaking of the draining of the 'Great Level' in the Fens was only drawn up in 1630, work beginning in 1631. The idea of draining and enclosing Sedgemoor in Somerset had arisen in 1621, but little happened until 1656 when Vermuyden petitioned Cromwell to drain it. The bill for this purpose was defeated and Sedgemoor had to wait till 1791 to be drained.

It was in 1616 that Henry Gibb, son of John Gibb, obtained a grant of "lands called Brading ... which have been much overflowed by the sea, and are to be inclosed at his expense" (S.P.Dom. 1611-18, p.381). By 1620, the Court of Exchequer found in favour of the King against the Island landowners and so Thelwell set to work. He invited Sir Hugh Middleton to join him in the venture and to manage the reclamation works. Middleton was a London goldsmith originally, but like many early 17th century "adventurers", he invested in various undertakings, such as the New River Company the "Royall Mines" in Wales. Both the Middleton and Thelwell families were neighbours in Denbighshire and both men knew each other well.

Middleton brought over Dutch engineers to undertake the reclamation, which started in December 1620 and was completed by 1622. Out of "706 akers", Oglander reckoned only 200 were worth 6s. 8d., while the rest was poor grade land, only worth 2s, 6d. an acre. Middleton tried a variety of crops on the new land but all, except for rape seed, were very disappointing. He also constructed a barn, a dwelling house and a water mill, as well as planting many enclosure hedges and digging drainage ditches across the reclaimed land.

In 1624, Middleton sold his interest to Thelwell, so that he, Thelwell, now had full ownership of the reclaimed lands. However, on 8 March 1630, the sea broke through the east end of the embankment. High rainfall had swollen the waters draining off the reclaimed lands in the River Yar and normally the sluices could cope. However a high spring tide, meeting with this excess of fresh water on the other side of the embankment had undermined it at its weakest point - the eastern end. This section, as indeed all the spit (called at a later date St. Helen's Dover), belonged to the Worsley family. Since the male heir at that time, Harry Worsley, was still a minor, his mother, Lady Worsley, was the head of the family. Thelwell immediately set off for the Island with a letter from Lord Conway, the Governor of the Island, to his deputies, requesting them to tell Lady Worsley to mend the breach. She refused, saying she believed the law would not require her to do so, but obviously put it in more diplomatic language. Thelwell, in several later court actions, failed each time in his bid to make the Worsleys pay for the repairs needed. In these court actions, Worsley successfully proved his title to the haven and Thelwell's action was thrown out of court. Thelwell eventually gave up trying to regain possession of the haven and finally in about 1652, Sir Harry Worsley was officially given ownership of the haven, thus restoring to the Worsley family the right to the haven. Possibly, one reason why the verdicts went against Thelwell was because he was associated as a court favourite with the Royal family and therefore in the unsettled times from 1640, the Parliamentarian courts were not sympathetic to his cause.

Worsley's right to the haven dated back to Medieval times when the Lords of Wolverton, La Wode and Middleton owned the fishery rights of the haven. In 1616, Brading Haven had been effectively usurped by the Crown, who claimed it was a bona fide haven, rather than drowned former lands and therefore it belonged to it. As mentioned above, local landowners, including the Worsleys, were defeated in the Court of the Exchequer and the haven was acquired, rather illegally, by James to give to his favourites. This may be yet another reason why several of the gentry were indisposed towards the Crown on the eve of the Civil War. In 1657, Worsley granted a lease of the haven to a Mr. Dickenson and a Mr. Hutchinson, who, knowing that his right to it was secure, again reconstructed the old embankment and reclaimed the haven to pasture. However, due to the carelessness of some of the workmen, the sea broke through again. Dickenson and Hutchinson were unable to raise the necessary money to repair the damage and the haven remained flooded until the 19th century when Jabez Balfour and the Liberator Company built the present, much longer embankment, which has successfully kept out the sea from Brading pastures.

Not everyone was supportive of the reclamation works and like in the Fens and at Hatfield Chase, many of the people who relied on the haven for their livelihood were unhappy about the transformation of the marshes and estuary into pastures. The haven had provided fish and seafood , wild foul and sedges and reeds for roofing. However, the number of people who directly earned a living from the haven can only have been small and therefore very little active resistance, as in the Fens, was witnessed. When the bank finally did give way, Oglander mentions that the "commoner sorte" were "glad". Indeed, "those wiked people of St Ellins and bembridge" actually helped themselves to the stones and shingle from the damaged area to use in patching up their roads, thereby aggravating the situation, much to the anger of Thelwell. As Deputy-Lieutenant of the Island, Oglander also had misgivings about the reclaimed land, for he felt that it now provided a perfect opportunity for an enemy to land his troops easily.

A note of other defectes within ye Isle of Wight
Therre wantes a fforte to be Bwilded at St. Hellens for since ye Haven there wase Inned by Sr Bevis Thelwell, and Middelton itt is by that meanes made ye best landinge place for ye enemie within Owre Islande.
The Inning of Brading Haven : Sir John Oglander's account.

The Construction of the Reclamation Works.
When Rychardes constructed his bank across the haven in 1594, he used clay with stones mixed in to construct his bank. This was then faced with a revetment wall of stone. Middleton's embankment would require a more substantial construction since it would have to face the full force of the sea, especially in north to north-easterly storms.

It seems he started by driving a long line of piles from Bembridge along the seaward line of the duver spit across to a point close to St. Helens church. Rocks were then piled in behind this line, in a similar fashion to a section of old coastal defence at the south end of Seagrove Bay.[right]

In a letter to his friend, Sir John Wynn of Qwydir in Wales, who was hoping to reclaim marshland on his land, Sir Hugh Middleton referred to the rocks that were used on the Island and that Wynn would need for his reclamation.

"Touchinge the drowned lands near your lyvinge, there are many things considerable therein. Iff to be gayned, which will hardlie be performed without great stones, which was plentifull at the Weight [Isle of Wight], as well as wood; and great sums of money to be spent, not hundreds, but thousands - and first of all his Majesty's interest must be got".
Letter from Sir Hugh Middleton to Sir John Wynn of Qwydir, Wales. 2 Sept. 1625. (No. 1367, Cal. Wynn Papers, National Library Wales)
The stones were easily acquired from a beach quarry adjacent to St. Helen's church. Indeed it may have been the removal of these stones from the foreshore that caused the rapid erosion of churchyard and church of St. Helen's.

Seeing as Dutchmen were involved, then presumably similar techniques to those they used in the Netherlands can be expected. Some sort of packing material, most probably clay, would be used to cover the rocks and consolidate it all. In 1699, Worsley had an estimate drawn up for re-establishing the embankment again on roughly the same line as the original. Money was to be spent on making a wall that was "to consist of the nearest matter at hand; which is a strong stiffe clay". To provide strength, "some other proper materials" were to be added to the clay, in a similar way to Rychardes's 1594 embankment. All these materials needed "filling" and "ramming" into the stones, positioned behing the row of piles. In time, grass would be grown on these embankments and this would help to further knit the whole mass. However, given what Oglander says about the rapid accumulation of sand in those parts, it was not long before the whole bank was covered in sand.

The Destruction of the Reclamation Works.
On 8 March 1630, a number of factors, acting in conjunction, caused the breaching of the embankment which in turn led to the reflooding of Brading Haven, which would remain a tidal inlet until the late 19th century. The breach occurred at the eastern end of the embankment in the area slightly to the west of the old Spithead Hotel.

Oglander considers the reason for the breach was a simultaneous high spring tide and a haven full of fresh water.

The cawse of ye laste breache wase by reason of a wet tyme when the hauen was ful of fresch, and then a high springe tyde, when boath the waters met underneathe in the loose sand. (OG/90/4)
Later in the same Commonplace Book, he also highlights the fact that an accumulation of sand at the sluice outlet also played a part in overcoming the works. Even today a great amount of sand and shingle accumulates at the mouth of the harbour and it is this propensity for sand to be deposited in this area that has lead to the forming of the large shoal of sand on the Bembridge side as well as having caused the swamping of the old harbour wall.
The greate inconvenionce wase, in itt ye seae browght so mutch sand and ooaze and seaeweed that choaked up the passage of ye fresch to go owt; insomutch that I am of opynion that if ye seae had not broake in, Sir Bevis coold hardlie haue kept itt; for ther woold haue been no current for the fresch to go owt; for ye easterne tydes browght so mutch sand that ye fresch wase not of fforce to drive itt awaie, so that in tyme itt woold have lain to ye seae, or else ye fresch woold haue drowned ye whoole countery.
And later on in the same book, Oglander points out that so much is deposited on the east side of the breach that the spit on the Bembridge side was growing in a westerly direction. This elongation towards St. Helen's continued for the next two centuries but now, due to modern harbour works, has slowed down.
ye hedland on Bindbridge Syde is Sutch as Upon an Eastorly, South or Northeastorly wynd casteth up so mutch Sand and Beach in those partes as forceth ye Haven to winn Courrant ffarthor, and to loose land to ye Eastward, as for example, this last Breach hapened in March 1630, in our yere ye Hedland had vomited up so mutch Sande and Beach on ye Eastormost syde of ye Breach, yt it forced ye Courrant to gayne to ye westward and hath gayned in our yere a yarde or 2 to ye East of what it wase when ye Breach wase first made so that it is my Opinion that in a matter of 100 yeres or littel more ye Courrant will come to St Hellens syde and be in Statu quo prius./ Hereupon I conclude yt the Breache may safely be stopped, but by reason of the hedland in Binbridge syde it will be a difficult mattor to gayne a passage to Continnue and abyd free and open for ye Conveyance of ye ffresch. my Sonn meddle not with it : Monitus: Munitus:
This was still a problem in the late 18th century when Hassell was writing about Brading Haven.
Many attempts have been made to procure a constant entrance into this haven for ships of burden, but without success; the sand being driven in as fast as it is cleared away.
Tour of the ISLE OF WIGHT by J. Hassell (T. Hookham, London. 1790)
Due to the complex system of tides, a large amount of sand and gravel is deposited on the shore of the Bembridge side of the haven mouth, accumulating to form extensive sands that stretch out towards St. Helen's Fort. A direct cause of much of this is the longshore drift in these parts. From Whitecliff Bay, the direction of the longshore drift is south to north. This continues round Forelands and so on until Seaview. However, the presence of the waters of the haven ebbing and flowing disturbs this drift, which allows for a larger scale of accumulation and deposition of sand in the lee of Forelands. These sands are also evident off Priory and Seagrove Bay within a zone between two tidal streams, where large sandbanks and shoals are uncovered at low tides.

However, Sir Bevis Thelwell points to a more human cause for the failure of the embankment, for he presents the fact that Worsley's tenants were removing sand and shingle from the bank to mend the local roads.

And wheareas youe say in your letter that the makeinge of my banke in stoppinge the sea of his ould Corrant was the cause of this breach it doth Evidently appeare that the takeinge away of the beach & stones was the cause of it more then any thinge els,... (OG/16/4)
Possibly this removal of materials had lowered or weakened the bank at the eastern end to a dangerous extent. With an excess of fresh water in the reclaimed lands behind the embankment, coupled with a high spring tide, that would have caused the sluice to be firmly shut, the dam wall was simultaneously overcome by waves and undermined by ground water at the weakest point - the eastern area where the bank had been reduced by the removal of sand and shingle.