Simeon Disley

Case Study - Wrangle seabank project

Life, as they say, is full of changes.  One of the changes the people of South Lincolnshire are going to have to adjust to is the predicted increase in sea levels of one metre in the next 100 years.

They have already had several tastes of what may be to come.

The Witham Fourth District Internal Drainage Boards records at the Hop Hole pumping station show that the highest recorded tide on 31 January 1953 was 5.2 metres. This rose to 5.49 metres on 11 January 1978.  And on 5 December 2013, the tide was at a height of six metres.  The effect of that tide on the town of Boston is well known and the flooding of some 400 properties received significant publicity.

However, there was also substantial damage in the surrounding countryside which received comparatively little public attention. 

The sea bank from Boston to Skegness is, on average, at least one metre lower than the banks to the south of Boston.

In many places the water overflowed the tops of the bank in what is known as an “over-topping event”, resulting in the flooding of adjacent agricultural land.  The Jubilee Bank at Friskney, so called because it was constructed in 1977, and the mostly recently erected sea bank, was breached in three places, causing 550 acres of arable land to be flooded with 900 million litres of sea water. 

The image below shows the extent of the damage.  The water was prevented from reaching further inland by the 1948 bank.

It is worth giving some thought to the effect of land reclamation from the sea. The plan below shows the land mass in the 1300s compared with the current coastline.  “Joy Hill” at Wrangle is so named as at that time it was the high land adjacent to a small estuary. 


The pictures below show the extent and timings of subsequent reclamations.


Reclamation over the years had two benefits.  Firstly, it expanded the area of land available for agriculture production.  Secondly, and possibly not so immediately apparent, each reclamation resulted in an improvement to the sea defences.  However, in 1982 following a public enquiry, further reclamations were prohibited on the grounds that accretion – which is the creation of new land by silting-up - in this case of The Wash – had ceased.  In 2010, the Ordnance Survey carried out a survey of the coastline of The Wash at the request of Roythornes partner, Simeon Disley.  This showed approximately 10,000 acres of additional land had accreted over the previous 50 years, which does suggest that the evidence given to the public enquiry was incorrect.

As a result, there were no substantial improvements to the sea banks along the coastline of The Wash for some 35 years.  This, in the context of sea level rise, made it inevitable that major flooding would happen at some point.  Whilst the events of December 2013 were awful, perhaps there is a small silver lining in that it focused minds on the perilous state of our sea defences.

The potential susceptibility of Boston to flooding has been identified as a major issue for some years now.  It has hampered development in the area and the Boston Flood Barrier was planned long before December 2013. 

Further protection for the surrounding countryside, however, was not on the agenda.  In fact, policy was leaning towards “managed retreat”.  The reasons for this were inevitably financial.  In the Environment Agency’s model, at a time of public financial constraint, an agricultural area with low household density is a low priority for funding.

Common sense suggests that Boston’s economy is primarily based on the surrounding agricultural industry with the mass employers of the vegetable sector centred on the reclaimed land to the north of the town.

To really protect Boston, and other towns in the Fens, the surrounding agricultural land must be preserved.  It is also worth remembering that 55% of UK electricity generation is based in low lying areas protected by internal drainage boards.

The flooding of farm land in 2013 served as a wakeup call to a number of local farmers.  Stafford Proctor, whose family farms in the Sutton Bridge area, decided to reform The Wash Frontagers Group – a group which had not met since the 1982 public enquiry, when further reclamation was banned.  Landowners and tenants along the coastline from Gibraltar Point to Wolferton Creek were identified; Stafford became the group’s chairman, with Simeon Disley alongside him as vice.  The group is, indeed, a diverse one and its members include charities, corporate bodies and individuals, ranging from the Royal Family at Sandringham to Mr Cheffin who owns 160 metres of sea frontage at Leverton.

In August 2014 a meeting was attended by the majority in number of the landowners, who in turn farmed a far greater majority of the land, and a committee was formed with a mandate to campaign for improvements in the sea defences around The Wash.

It was identified that the forthcoming General Election in 2015 would provide an opportunity to push local flood defence improvements up the political agenda.

As luck would have it, the area was being put under a spotlight due to the activities of UKIP, and it was anticipated to be a very close election.  Local candidates could not afford to be seen to not be paying attention to the flood risk issue following the storm in December 2013.

Meetings were held with the major local election candidates.  They were invited to photo calls which were publicised by the National Farmers Union and the Country Landowners Association.  Further meetings with two successive Secretaries of State – Owen Patterson and Liz Truss were also held. 

The Wash Frontagers Group was delighted to hear that the Environment Agency had offered some money for improvements to the lowest lying sector of the sea bank which is between Leverton and Wrangle.  Nobody was under any illusion that this was to protect agriculture.  Large sections of this bank date back to 1810 and there is no bank behind it.  This left the population of Wrangle exposed to catastrophic flooding. 

According to the Environment Agency, a minimum sea bank height of 6.5 metres was sufficient.   The events of 2013 had proved that this was incorrect and subsequent surveys revealed that, in the Leverton to Wrangle section, some areas of the bank were beneath six metres in height, hence the substantial over-topping. 

In an attempt to increase awareness of the issue, the Environment Agency, members of the local drainage boards and local politicians were also invited to the Wash Frontagers Group’s meeting in August 2014.  Conversations followed and flood defence works started to appear on agendas.  The Lincolnshire Local Enterprise Partnership (LEP) provided further support for the issue and recognised the importance of water management for the economy of the area as whole.The Environment Agency confirmed that the funding available was £570,000 and they could not deliver the works for such an amount.

Peter Bateson, the chief executive of the Witham Fourth District Internal Drainage Board, stepped in with the novel suggestion that the drainage board would act as “agent” for the Environment Agency in managing the works and procuring them through their own model.  In simple terms, a drainage board can deliver two pounds’ worth (or more) of value for an Environment Agency one pound. 

With the support of the LEP, an application was made to the EU for further funding on the grounds that the Lincolnshire economy needed protection from flooding and a further half a million pounds was made available. 

The funding could be used to raise the section of bank to a height of 7 metres.  This would be the first major improvement to sea defences since 1982 and, as such, would send a very important political message – managed retreat was no longer the prevailing policy.

A sea bank provides protection not only by its height by also by its design and it was the design of the 1977 bank at Friskney which may have contributed to its collapse.  It should also be borne in mind that the presence of badger sets in a sea bank is estimated to reduce its strength by some 70%.  In December 2013, torrents of water could be seen projecting through badger holes in the sea banks.  The design of the majority of the eastern sea banks is that they have steep sides to their rear, so if over-topping does occur, run-off has real momentum which can “eat away” the soft landward side of the bank, thus leading to collapse from its back.

In addition to increasing the height of the banks, the rear sides need to be re-profiled to a gradient of 1:3 so that any flow over the top is taken gently away into new large drains without creating erosion.

Over-topping only occurs for a short period of time.  The all-important factor here is delivering the extra protection from damage during these crucial minutes.

Even with the funding in place, there were still significant issues to be addressed.

Traditionally, sea banks were built with material from the seaward side, which is excavated from “borrow pits” in the marsh.  The marshland in The Wash is amongst the most protected areas in the country.  In some places, it has been subject to six different environmental classifications, including an SSSI and Ramsar site.  A farmer whose sea bank collapsed in 2013 was threatened with prosecution for driving on the adjacent marsh to inspect the damage to the sea bank.

It is a great irony that one of the few things you are, in fact, allowed to do on some parts of the out-marsh is to blow it up.  That, apparently, is in the national interest.  RAF Holbeach, based on The Wash, is the home of the National High Altitude Bombing Range and the Americans use the marsh as a long range bombing test facility, too.

The proposal for the new works was that the material would be procured from the landward side of the new bank by removing the topsoil and extracting down to a depth of an average of .85 metres.  This would result in a strip of land, on average, some 35 metres in depth from the current base of the sea banks losing agricultural productivity. 

To the fourteen farmers who, between them, owned some of the largest farming operations in the area, the decision was a “no brainer”.  To a minority of the smaller-scale landowners, the loss of productive capacity (particularly of organic pasture land) was a bitter pill to swallow.

Simeon Disley was invited to join the project board formed to oversee the proposed works, working alongside representatives from the Witham Fourth Internal Drainage Board, the Environment Agency, Natural England and the consulting engineers.

By February 2017, the funding from the Environment Agency and European Union was agreed.  However, different sources of funding had different requirements.  The UK funding was to be spent with a degree of supervision.  The European funding, on the other hand, was promised on the basis that once the works had been completed, the project would then be evaluated and if it was felt the funds had not been spent in a satisfactory manner, then funds could be subject to a “clawback”.  This presented the project board with a substantial problem in that the drainage board, which was managing the project, was not in a financial position to underwrite the project. They were lending their management expertise and it was not appropriate for them to bear a potential loss on it. 

Another possible option was to ask the 14 landowners to underwrite the works, but this presented two further difficulties.  Firstly, the works were not being carried out solely for their benefit so why should they bear the potential cost of a clawback?  And secondly, trying to agree terms quickly to satisfy the European Union would be practically impossible. 

Lincolnshire County Council seemed a suitable candidate to help out in that they had the financial resources which were easily accessible and also their role in society is meant to be for the benefit of all. 

Peter Bateson, who is chief executive of the Witham Fourth Drainage Board and was chairing the project, met with Matt Warman MP in London and, shortly afterwards, Lincolnshire County Council were approached. 

At this point, it should be mentioned that increasing the height of the bank by an additional half metre above the level which the Environment Agency said was required was a pivotal moment in the project.  It would prove to be of both practical and political significance; it would set a standard for improving the height of all sea banks around The Wash.

Lincolnshire County Council, to their credit, were very cooperative and quickly agreed to underwrite the works.  Having agreed to do so, it was then necessary to ascertain that they were allowed to do so as the project board would not want to be exposed to them having acted outside their powers in the unlikely event that the clawback were to apply.  The required clearance was obtained following advice from another Roythornes partner, Peter Cusick.

To qualify for European funding, the works had to be offered out to tender under the rules of the OJEU (Official Journal of the European Union) which, in turn, meant it had to be advertised on a national contract tender portal for six weeks. 

Between August and October 2017 the ten submitted tenders were evaluated and ranked, based on price and qualitative factors.  The tenders also had to be evaluated to ensure they complied with environmental standards and that all the contracted works had been included.  References were also taken up.  The contract tender was awarded to D Morgan plc in October 2017. 

Simeon Disley represented the landowners and tenants, and spent 10 days visiting them all to understand their different requirements.  Many practical issues, such as interaction with the HLS agreements, BPS payments and maintaining access for grazing cattle on the out-marsh had to be addressed.  Between June and October 2017 Simeon negotiated agreements between the landowners and tenants and the drainage board to make sure the soil from the farmland was available to complete the project.  Two areas of land affected were ancient grazing and so material could not be extracted from them.

The last of the agreements was signed in November 2017. 

Also to be considered was the fact that the vast majority of the sea bank was a public footpath, so arrangements had to be made for it to be closed during the construction period and also for a up to two years afterwards.  This was to prevent any damage being caused to the bank during the vital settlement period, when the newly seeded grass was establishing itself.

Lincolnshire County Council can consent to the closure of a footpath for a period of six months; to go beyond that, Government consent is required. There was concern, therefore, that the timescale for closure of the sea bank would clash with proposals for a national coastal footpath. However, to date these issues have not materialised into practical problems.

In February 2018, a photographic study of the 5.8 kilometre section of the sea bank was made to record all the existing fencing, gates, water troughs and other features along the stretch of bank to ensure that they could be accurately replaced.  After the study was completed, all such features, together with the vegetation, was cleared to prevent nesting birds later in the year causing any delays to the project.

The proposed commencement date of the works was set for 3 April 2018.  The timescale was very tight - the project had to be completed by mid-September at the very latest, to avoid potential disturbance to migrating birds arriving on the adjacent out-marsh, which is an environmentally protected area.  When the day came, it rained very heavily and continued to do so, delaying the start by 13 days. 

As the water level in the area was very high, the extracted material was wet and had to be left to dry before it could be used.  Any long periods of rainfall or delay would have had severe consequences for the project and was of considerable concern at the time. 

There was also another practical problem.  It was a requirement that a metal detector scan of the site be carried out shortly before works commenced to identify any potential unexploded bombs.  This is standard industry practice. The expectation of a scan of an area such as this was that some 200 “potential hotspots” might be identified for further investigation.  Our survey results revealed some 3,000 areas of interest. 

There was grave concern when we found out that during World War II the Wrangle Home Guard had a cannon which they fired on a Sunday morning.  It sent explosive shells over the village which landed in the then out-marsh.  Post war reclamations meant these shelled areas were now in the fields we had to work in.  In addition, the Home Guard did, on occasions, like to have a bit of hand grenade practice, and so sea banks provided the ideal barriers over which hand grenades were thrown.  Sometimes, they failed to go off and have subsequently turned up on potato grading lines in the area.

A more refined metal detecting survey was carried out, to separate the wheat from the chaff, or rather the unexploded ordinance from shrapnel.  Luckily no UXBs were found, just a lot of old horseshoes and twisted metal.

The long hot dry summer of 2018 was a blessing; the extracted material dried out quickly and was able to be used.

As far as the land owners were concerned, it soon became apparent that the cost of bringing in material to the sea frontage by lorry was prohibitive.  After a round of negotiations, some neighbouring landowners agreed to give up additional soil, in return for a small payment, to make up the missing material.

As part of the process, in order to allow grazing cattle on the out-marsh to escape from high tides, access over the bank had to be maintained.  The accesses had to be re-profiled to take into account the increased gradient of the raised level of the sea bank.

As construction came to a close in August 2018, the cattle fencing, water troughs and gates were all reinstated, as planned.  The new sea bank will be fenced off from cattle as well as walkers for some two years.

The project was completed in September 2018 and there is a defects period for a further 12 months.

The successful completion of the works is something all involved are immensely proud of.

The model of partnership, with a local body spending national money in partnership with private individuals, delivered an economy of at least 50% and can deliver more flood defence works than the EA, for each £1 spent.  Having proved it can be successfully delivered, it has been proposed to use it elsewhere in the country.